DATAMONGO-2454 - Release version 3.0 M2 (Neumann).

Previously we falsely converted the sort value (1/-1) into the id types target value when a Field annotation had been present.

Original pull request: #822.

.travis.yml

@@ -0,0 +1,38 @@
+language: java
+
+jdk:
+  - oraclejdk8
+
+before_install:
+  - mkdir -p downloads
+  - mkdir -p var/db var/log
+  - if [[ ! -d downloads/mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION} ]] ; then cd downloads && wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION}.tgz && tar xzf mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION}.tgz && cd ..; fi
+  - downloads/mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION}/bin/mongod --version
+  - downloads/mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION}/bin/mongod --dbpath var/db --replSet rs0 --fork --logpath var/log/mongod.log
+  - sleep 10
+  - |-
+    downloads/mongodb-linux-x86_64-ubuntu1604-${MONGO_VERSION}/bin/mongo --eval "rs.initiate({_id: 'rs0', members:[{_id: 0, host: '127.0.0.1:27017'}]});"
+    sleep 15
+
+env:
+  matrix:
+    - MONGO_VERSION=4.1.10
+    - MONGO_VERSION=4.0.4
+    - MONGO_VERSION=3.6.12
+    - MONGO_VERSION=3.4.20
+  global:
+    - PROFILE=ci
+
+addons:
+  apt:
+    packages:
+      - oracle-java8-installer
+
+sudo: false
+
+cache:
+  directories:
+    - $HOME/.m2
+    - downloads
+
+script: "mvn clean dependency:list test -P${PROFILE} -Dsort"

Jenkinsfile

@@ -1,123 +1,219 @@
 pipeline {
-    agent none
+	agent none
 
-    triggers {
-        pollSCM 'H/10 * * * *'
-        upstream(upstreamProjects: "spring-data-commons/2.1.x", threshold: hudson.model.Result.SUCCESS)
-    }
+	triggers {
+		pollSCM 'H/10 * * * *'
+		upstream(upstreamProjects: "spring-data-commons/master", threshold: hudson.model.Result.SUCCESS)
+	}
 
-    options {
-        disableConcurrentBuilds()
-        buildDiscarder(logRotator(numToKeepStr: '14'))
-    }
+	options {
+		disableConcurrentBuilds()
+		buildDiscarder(logRotator(numToKeepStr: '14'))
+	}
 
-    stages {
-        stage("Test") {
-            when {
-                anyOf {
-                    branch '2.1.x'
-                    not { triggeredBy 'UpstreamCause' }
-                }
-            }
-            parallel {
-                stage("test: baseline") {
-                    agent {
-                        docker {
-                            image 'springci/spring-data-openjdk8-with-mongodb-4.0:latest'
-                            label 'data'
-                            args '-v $HOME:/tmp/jenkins-home'
-                        }
-                    }
-                    options { timeout(time: 30, unit: 'MINUTES') }
-                    steps {
-                        sh 'rm -rf ?'
-                        sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
-                        sh 'mongod --dbpath /tmp/mongodb/db --replSet rs0 --fork --logpath /tmp/mongodb/log/mongod.log &'
-                        sh 'sleep 10'
-                        sh 'mongo --eval "rs.initiate({_id: \'rs0\', members:[{_id: 0, host: \'127.0.0.1:27017\'}]});"'
-                        sh 'sleep 15'
-                        sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw clean dependency:list test -Dsort -U -B'
-                    }
+	stages {
+		stage("Docker images") {
+			parallel {
+				stage('Publish JDK 8 + MongoDB 4.0') {
+					when {
+						changeset "ci/openjdk8-mongodb-4.0/**"
+					}
+					agent { label 'data' }
+					options { timeout(time: 30, unit: 'MINUTES') }
+
+					steps {
+						script {
+							def image = docker.build("springci/spring-data-openjdk8-with-mongodb-4.0", "ci/openjdk8-mongodb-4.0/")
+							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
+								image.push()
+							}
+						}
+					}
+				}
+				stage('Publish JDK 8 + MongoDB 4.1') {
+					when {
+						changeset "ci/openjdk8-mongodb-4.1/**"
+					}
+					agent { label 'data' }
+					options { timeout(time: 30, unit: 'MINUTES') }
+
+					steps {
+						script {
+							def image = docker.build("springci/spring-data-openjdk8-with-mongodb-4.1", "ci/openjdk8-mongodb-4.1/")
+							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
+								image.push()
+							}
+						}
+					}
+				}
+				stage('Publish JDK 8 + MongoDB 4.2') {
+                	when {
+                		changeset "ci/openjdk8-mongodb-4.2/**"
+                	}
+                	agent { label 'data' }
+                	options { timeout(time: 30, unit: 'MINUTES') }
+
+                	steps {
+                		script {
+                			def image = docker.build("springci/spring-data-openjdk8-with-mongodb-4.2", "ci/openjdk8-mongodb-4.2/")
+                			docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
+                				image.push()
+                			}
+                		}
+                	}
                 }
+			}
+		}
 
-            }
-        }
+		stage("test: baseline") {
+			when {
+				anyOf {
+					branch 'master'
+					not { triggeredBy 'UpstreamCause' }
+				}
+			}
+			agent {
+				docker {
+					image 'springci/spring-data-openjdk8-with-mongodb-4.2:latest'
+					label 'data'
+					args '-v $HOME:/tmp/jenkins-home'
+				}
+			}
+			options { timeout(time: 30, unit: 'MINUTES') }
+			steps {
+				sh 'rm -rf ?'
+				sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
+				sh 'mongod --dbpath /tmp/mongodb/db --replSet rs0 --fork --logpath /tmp/mongodb/log/mongod.log &'
+				sh 'sleep 10'
+				sh 'mongo --eval "rs.initiate({_id: \'rs0\', members:[{_id: 0, host: \'127.0.0.1:27017\'}]});"'
+				sh 'sleep 15'
+				sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw clean dependency:list test -Dsort -U -B'
+			}
+		}
 
-        stage('Release to artifactory') {
-            when {
-                branch 'issue/*'
-                not { triggeredBy 'UpstreamCause' }
-            }
-            agent {
-                docker {
-                    image 'adoptopenjdk/openjdk8:latest'
-                    label 'data'
-                    args '-v $HOME:/tmp/jenkins-home'
-                }
-            }
-            options { timeout(time: 20, unit: 'MINUTES') }
+		stage("Test other configurations") {
+			when {
+				anyOf {
+					branch 'master'
+					not { triggeredBy 'UpstreamCause' }
+				}
+			}
+			parallel {
+				stage("test: mongodb 4.0") {
+					agent {
+						docker {
+							image 'springci/spring-data-openjdk8-with-mongodb-4.0:latest'
+							label 'data'
+							args '-v $HOME:/tmp/jenkins-home'
+						}
+					}
+					options { timeout(time: 30, unit: 'MINUTES') }
+					steps {
+						sh 'rm -rf ?'
+						sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
+						sh 'mongod --dbpath /tmp/mongodb/db --replSet rs0 --fork --logpath /tmp/mongodb/log/mongod.log &'
+						sh 'sleep 10'
+						sh 'mongo --eval "rs.initiate({_id: \'rs0\', members:[{_id: 0, host: \'127.0.0.1:27017\'}]});"'
+						sh 'sleep 15'
+						sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw clean dependency:list test -Dsort -U -B'
+					}
+				}
+				stage("test: mongodb 4.1") {
+					agent {
+						docker {
+							image 'springci/spring-data-openjdk8-with-mongodb-4.1:latest'
+							label 'data'
+							args '-v $HOME:/tmp/jenkins-home'
+						}
+					}
+					options { timeout(time: 30, unit: 'MINUTES') }
+					steps {
+						sh 'rm -rf ?'
+						sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
+						sh 'mongod --dbpath /tmp/mongodb/db --replSet rs0 --fork --logpath /tmp/mongodb/log/mongod.log &'
+						sh 'sleep 10'
+						sh 'mongo --eval "rs.initiate({_id: \'rs0\', members:[{_id: 0, host: \'127.0.0.1:27017\'}]});"'
+						sh 'sleep 15'
+						sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw clean dependency:list test -Dsort -U -B'
+					}
+				}
+			}
+		}
 
-            environment {
-                ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
-            }
+		stage('Release to artifactory') {
+			when {
+				anyOf {
+					branch 'master'
+					not { triggeredBy 'UpstreamCause' }
+				}
+			}
+			agent {
+				docker {
+					image 'adoptopenjdk/openjdk8:latest'
+					label 'data'
+					args '-v $HOME:/tmp/jenkins-home'
+				}
+			}
+			options { timeout(time: 20, unit: 'MINUTES') }
 
-            steps {
-                sh 'rm -rf ?'
-                sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
-                        '-Dartifactory.server=https://repo.spring.io ' +
-                        "-Dartifactory.username=${ARTIFACTORY_USR} " +
-                        "-Dartifactory.password=${ARTIFACTORY_PSW} " +
-                        "-Dartifactory.staging-repository=libs-snapshot-local " +
-                        "-Dartifactory.build-name=spring-data-mongodb-2.1 " +
-                        "-Dartifactory.build-number=${BUILD_NUMBER} " +
-                        '-Dmaven.test.skip=true clean deploy -U -B'
-            }
-        }
+			environment {
+				ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+			}
 
-        stage('Release to artifactory with docs') {
-            when {
-                branch '2.1.x'
-            }
-            agent {
-                docker {
-                    image 'adoptopenjdk/openjdk8:latest'
-                    label 'data'
-                    args '-v $HOME:/tmp/jenkins-home'
-                }
-            }
-            options { timeout(time: 20, unit: 'MINUTES') }
+			steps {
+				sh 'rm -rf ?'
+				sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
+						'-Dartifactory.server=https://repo.spring.io ' +
+						"-Dartifactory.username=${ARTIFACTORY_USR} " +
+						"-Dartifactory.password=${ARTIFACTORY_PSW} " +
+						"-Dartifactory.staging-repository=libs-snapshot-local " +
+						"-Dartifactory.build-name=spring-data-mongodb " +
+						"-Dartifactory.build-number=${BUILD_NUMBER} " +
+						'-Dmaven.test.skip=true clean deploy -U -B'
+			}
+		}
 
-            environment {
-                ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
-            }
+		stage('Publish documentation') {
+			when {
+				branch 'master'
+			}
+			agent {
+				docker {
+					image 'adoptopenjdk/openjdk8:latest'
+					label 'data'
+					args '-v $HOME:/tmp/jenkins-home'
+				}
+			}
+			options { timeout(time: 20, unit: 'MINUTES') }
 
-            steps {
-                sh 'rm -rf ?'
-                sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
-                        '-Dartifactory.server=https://repo.spring.io ' +
-                        "-Dartifactory.username=${ARTIFACTORY_USR} " +
-                        "-Dartifactory.password=${ARTIFACTORY_PSW} " +
-                        "-Dartifactory.staging-repository=libs-snapshot-local " +
-                        "-Dartifactory.build-name=spring-data-mongodb-2.1 " +
-                        "-Dartifactory.build-number=${BUILD_NUMBER} " +
-                        '-Dmaven.test.skip=true clean deploy -U -B'
-            }
-        }
-    }
+			environment {
+				ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+			}
 
-    post {
-        changed {
-            script {
-                slackSend(
-                        color: (currentBuild.currentResult == 'SUCCESS') ? 'good' : 'danger',
-                        channel: '#spring-data-dev',
-                        message: "${currentBuild.fullDisplayName} - `${currentBuild.currentResult}`\n${env.BUILD_URL}")
-                emailext(
-                        subject: "[${currentBuild.fullDisplayName}] ${currentBuild.currentResult}",
-                        mimeType: 'text/html',
-                        recipientProviders: [[$class: 'CulpritsRecipientProvider'], [$class: 'RequesterRecipientProvider']],
-                        body: "<a href=\"${env.BUILD_URL}\">${currentBuild.fullDisplayName} is reported as ${currentBuild.currentResult}</a>")
-            }
-        }
-    }
+			steps {
+				sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,distribute ' +
+						'-Dartifactory.server=https://repo.spring.io ' +
+						"-Dartifactory.username=${ARTIFACTORY_USR} " +
+						"-Dartifactory.password=${ARTIFACTORY_PSW} " +
+						"-Dartifactory.distribution-repository=temp-private-local " +
+						'-Dmaven.test.skip=true clean deploy -U -B'
+			}
+		}
+	}
+
+	post {
+		changed {
+			script {
+				slackSend(
+						color: (currentBuild.currentResult == 'SUCCESS') ? 'good' : 'danger',
+						channel: '#spring-data-dev',
+						message: "${currentBuild.fullDisplayName} - `${currentBuild.currentResult}`\n${env.BUILD_URL}")
+				emailext(
+						subject: "[${currentBuild.fullDisplayName}] ${currentBuild.currentResult}",
+						mimeType: 'text/html',
+						recipientProviders: [[$class: 'CulpritsRecipientProvider'], [$class: 'RequesterRecipientProvider']],
+						body: "<a href=\"${env.BUILD_URL}\">${currentBuild.fullDisplayName} is reported as ${currentBuild.currentResult}</a>")
+			}
+		}
+	}
 }

SECURITY.adoc

@@ -0,0 +1,9 @@
+# Security Policy
+
+## Supported Versions
+
+Please see the https://spring.io/projects/spring-data-mongodb[Spring Data MongoDB] project page for supported versions.
+
+## Reporting a Vulnerability
+
+Please don't raise security vulnerabilities here. Head over to https://pivotal.io/security to learn how to disclose them responsibly.

ci/README.adoc

@@ -0,0 +1,39 @@
+== Running CI tasks locally
+
+Since Concourse is built on top of Docker, it's easy to:
+
+* Debug what went wrong on your local machine.
+* Test out a a tweak to your `test.sh` script before sending it out.
+* Experiment against a new image before submitting your pull request.
+
+All of these use cases are great reasons to essentially run what Concourse does on your local machine.
+
+IMPORTANT: To do this you must have Docker installed on your machine.
+
+1. `docker run -it --mount type=bind,source="$(pwd)",target=/spring-data-mongodb-github springci/spring-data-8-jdk-with-mongodb /bin/bash`
++
+This will launch the Docker image and mount your source code at `spring-data-mongodb-github`.
++
+Next, run the `test.sh` script from inside the container:
++
+2. `PROFILE=none spring-data-mongodb-github/ci/test.sh`
+
+Since the container is binding to your source, you can make edits from your IDE and continue to run build jobs.
+
+If you need to test the `build.sh` script, do this:
+
+1. `mkdir /tmp/spring-data-mongodb-artifactory`
+2. `docker run -it --mount type=bind,source="$(pwd)",target=/spring-data-mongodb-github --mount type=bind,source="/tmp/spring-data-mongodb-artifactory",target=/spring-data-mongodb-artifactory springci/spring-data-8-jdk-with-mongodb /bin/bash`
++
+This will launch the Docker image and mount your source code at `spring-data-mongodb-github` and the temporary
+artifactory output directory at `spring-data-mongodb-artifactory`.
++
+Next, run the `build.sh` script from inside the container:
++
+3. `spring-data-mongodb-github/ci/build.sh`
+
+IMPORTANT: `build.sh` doesn't actually push to Artifactory so don't worry about accidentally deploying anything.
+It just deploys to a local folder. That way, the `artifactory-resource` later in the pipeline can pick up these artifacts
+and deliver them to artifactory.
+
+NOTE: Docker containers can eat up disk space fast! From time to time, run `docker system prune` to clean out old images.

ci/openjdk8-mongodb-4.2/Dockerfile

@@ -0,0 +1,14 @@
+FROM adoptopenjdk/openjdk8:latest
+
+RUN apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2
+
+RUN apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv e162f504a20cdf15827f718d4b7c549a058f8b6b
+
+RUN echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list
+
+RUN apt-get update
+
+RUN apt-get install -y mongodb-org=4.2.0 mongodb-org-server=4.2.0 mongodb-org-shell=4.2.0 mongodb-org-mongos=4.2.0 mongodb-org-tools=4.2.0
+
+RUN apt-get clean \
+ && rm -rf /var/lib/apt/lists/*

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>2.1.22.BUILD-SNAPSHOT</version>
+	<version>3.0.0.M2</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data MongoDB</name>
@@ -15,21 +15,20 @@
 	<parent>
 		<groupId>org.springframework.data.build</groupId>
 		<artifactId>spring-data-parent</artifactId>
-		<version>2.1.22.BUILD-SNAPSHOT</version>
+		<version>2.3.0.M2</version>
 	</parent>
 
 	<modules>
 		<module>spring-data-mongodb</module>
-		<module>spring-data-mongodb-cross-store</module>
 		<module>spring-data-mongodb-distribution</module>
 	</modules>
 
 	<properties>
 		<project.type>multi</project.type>
 		<dist.id>spring-data-mongodb</dist.id>
-		<springdata.commons>2.1.22.BUILD-SNAPSHOT</springdata.commons>
-		<mongo>3.8.2</mongo>
-		<mongo.reactivestreams>1.9.2</mongo.reactivestreams>
+		<springdata.commons>2.3.0.M2</springdata.commons>
+		<mongo>3.12.0</mongo>
+		<mongo.reactivestreams>1.13.0</mongo.reactivestreams>
 		<jmh.version>1.19</jmh.version>
 	</properties>
 
@@ -118,30 +117,10 @@
 			<id>benchmarks</id>
 			<modules>
 				<module>spring-data-mongodb</module>
-				<module>spring-data-mongodb-cross-store</module>
 				<module>spring-data-mongodb-distribution</module>
 				<module>spring-data-mongodb-benchmarks</module>
 			</modules>
 		</profile>
-
-		<profile>
-			<id>distribute</id>
-			<build>
-				<plugins>
-					<plugin>
-						<groupId>org.asciidoctor</groupId>
-						<artifactId>asciidoctor-maven-plugin</artifactId>
-						<configuration>
-							<attributes>
-								<mongo-reactivestreams>${mongo.reactivestreams}</mongo-reactivestreams>
-								<reactor>${reactor}</reactor>
-							</attributes>
-						</configuration>
-					</plugin>
-				</plugins>
-			</build>
-		</profile>
-
 	</profiles>
 
 	<dependencies>
@@ -155,8 +134,8 @@
 
 	<repositories>
 		<repository>
-			<id>spring-libs-snapshot</id>
-			<url>https://repo.spring.io/libs-snapshot</url>
+			<id>spring-libs-milestone</id>
+			<url>https://repo.spring.io/libs-milestone</url>
 		</repository>
 	</repositories>
 

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.1.22.BUILD-SNAPSHOT</version>
+		<version>3.0.0.M2</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -87,6 +87,7 @@
 			<plugin>
 				<artifactId>maven-surefire-plugin</artifactId>
 				<configuration>
+					<useSystemClassLoader>false</useSystemClassLoader>
 					<testSourceDirectory>${project.build.sourceDirectory}</testSourceDirectory>
 					<testClassesDirectory>${project.build.outputDirectory}</testClassesDirectory>
 					<excludes>

spring-data-mongodb-cross-store/aop.xml

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<aspectj>
-    <aspects>
-        <aspect name="org.springframework.beans.factory.aspectj.AnnotationBeanConfigurerAspect" />
-        <aspect name="org.springframework.data.mongodb.crossstore.MongoDocumentBacking" />
-    </aspects>
-</aspectj>

spring-data-mongodb-cross-store/pom.xml

@@ -1,148 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd">
-
-	<modelVersion>4.0.0</modelVersion>
-
-	<parent>
-		<groupId>org.springframework.data</groupId>
-		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.1.22.BUILD-SNAPSHOT</version>
-		<relativePath>../pom.xml</relativePath>
-	</parent>
-
-	<artifactId>spring-data-mongodb-cross-store</artifactId>
-	<name>Spring Data MongoDB - Cross-Store Support</name>
-
-	<properties>
-		<jpa>2.1.1</jpa>
-		<hibernate>5.2.1.Final</hibernate>
-		<java-module-name>spring.data.mongodb.cross.store</java-module-name>
-		<project.root>${basedir}/..</project.root>
-	</properties>
-
-	<dependencies>
-
-		<!-- Spring -->
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-beans</artifactId>
-			<exclusions>
-				<exclusion>
-					<groupId>commons-logging</groupId>
-					<artifactId>commons-logging</artifactId>
-				</exclusion>
-			</exclusions>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-tx</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-aspects</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-orm</artifactId>
-		</dependency>
-
-		<!-- Spring Data -->
-		<dependency>
-			<groupId>org.springframework.data</groupId>
-			<artifactId>spring-data-mongodb</artifactId>
-			<version>2.1.22.BUILD-SNAPSHOT</version>
-		</dependency>
-
-		<!-- reactive -->
-		<dependency>
-		 	<groupId>io.projectreactor</groupId>
-			<artifactId>reactor-core</artifactId>
-			<optional>true</optional>
-		</dependency>
-
-		<dependency>
-			<groupId>org.aspectj</groupId>
-			<artifactId>aspectjrt</artifactId>
-			<version>${aspectj}</version>
-		</dependency>
-
-		<!-- JPA -->
-		<dependency>
-			<groupId>org.eclipse.persistence</groupId>
-			<artifactId>javax.persistence</artifactId>
-			<version>${jpa}</version>
-			<optional>true</optional>
-		</dependency>
-
-		<!-- For Tests -->
-		<dependency>
-			<groupId>org.hibernate</groupId>
-			<artifactId>hibernate-entitymanager</artifactId>
-			<version>${hibernate}</version>
-			<scope>test</scope>
-		</dependency>
-		<dependency>
-			<groupId>hsqldb</groupId>
-			<artifactId>hsqldb</artifactId>
-			<version>1.8.0.10</version>
-			<scope>test</scope>
-		</dependency>
-		<dependency>
-			<groupId>javax.validation</groupId>
-			<artifactId>validation-api</artifactId>
-			<version>${validation}</version>
-			<scope>test</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.hibernate</groupId>
-			<artifactId>hibernate-validator</artifactId>
-			<version>5.2.4.Final</version>
-			<scope>test</scope>
-		</dependency>
-
-	</dependencies>
-
-	<build>
-		<plugins>
-			<plugin>
-				<groupId>org.codehaus.mojo</groupId>
-				<artifactId>aspectj-maven-plugin</artifactId>
-				<version>1.6</version>
-				<dependencies>
-					<dependency>
-						<groupId>org.aspectj</groupId>
-						<artifactId>aspectjrt</artifactId>
-						<version>${aspectj}</version>
-					</dependency>
-					<dependency>
-						<groupId>org.aspectj</groupId>
-						<artifactId>aspectjtools</artifactId>
-						<version>${aspectj}</version>
-					</dependency>
-				</dependencies>
-				<executions>
-					<execution>
-						<goals>
-							<goal>compile</goal>
-							<goal>test-compile</goal>
-						</goals>
-					</execution>
-				</executions>
-				<configuration>
-					<outxml>true</outxml>
-					<aspectLibraries>
-						<aspectLibrary>
-							<groupId>org.springframework</groupId>
-							<artifactId>spring-aspects</artifactId>
-						</aspectLibrary>
-					</aspectLibraries>
-					<complianceLevel>${source.level}</complianceLevel>
-					<source>${source.level}</source>
-					<target>${source.level}</target>
-					<xmlConfigured>aop.xml</xmlConfigured>
-				</configuration>
-			</plugin>
-		</plugins>
-	</build>
-
-</project>

spring-data-mongodb-cross-store/src/main/java/org/springframework/data/mongodb/crossstore/MongoChangeSetPersister.java

@@ -1,214 +0,0 @@
-/*
- * Copyright 2011-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore;
-
-import javax.persistence.EntityManagerFactory;
-
-import org.bson.Document;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.springframework.dao.DataAccessException;
-import org.springframework.dao.DataAccessResourceFailureException;
-import org.springframework.dao.DataIntegrityViolationException;
-import org.springframework.data.crossstore.ChangeSet;
-import org.springframework.data.crossstore.ChangeSetBacked;
-import org.springframework.data.crossstore.ChangeSetPersister;
-import org.springframework.data.mongodb.core.CollectionCallback;
-import org.springframework.data.mongodb.core.MongoTemplate;
-import org.springframework.util.ClassUtils;
-
-import com.mongodb.MongoException;
-import com.mongodb.client.MongoCollection;
-import com.mongodb.client.model.Filters;
-import com.mongodb.client.result.DeleteResult;
-
-/**
- * @author Thomas Risberg
- * @author Oliver Gierke
- * @author Alex Vengrovsk
- * @author Mark Paluch
- * @deprecated will be removed without replacement.
- */
-@Deprecated
-public class MongoChangeSetPersister implements ChangeSetPersister<Object> {
-
-	private static final String ENTITY_CLASS = "_entity_class";
-	private static final String ENTITY_ID = "_entity_id";
-	private static final String ENTITY_FIELD_NAME = "_entity_field_name";
-	private static final String ENTITY_FIELD_CLASS = "_entity_field_class";
-
-	private final Logger log = LoggerFactory.getLogger(getClass());
-
-	private MongoTemplate mongoTemplate;
-	private EntityManagerFactory entityManagerFactory;
-
-	public void setMongoTemplate(MongoTemplate mongoTemplate) {
-		this.mongoTemplate = mongoTemplate;
-	}
-
-	public void setEntityManagerFactory(EntityManagerFactory entityManagerFactory) {
-		this.entityManagerFactory = entityManagerFactory;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.crossstore.ChangeSetPersister#getPersistentState(java.lang.Class, java.lang.Object, org.springframework.data.crossstore.ChangeSet)
-	 */
-	public void getPersistentState(Class<? extends ChangeSetBacked> entityClass, Object id, final ChangeSet changeSet)
-			throws DataAccessException, NotFoundException {
-
-		if (id == null) {
-			log.debug("Unable to load MongoDB data for null id");
-			return;
-		}
-
-		String collName = getCollectionNameForEntity(entityClass);
-
-		final Document dbk = new Document();
-		dbk.put(ENTITY_ID, id);
-		dbk.put(ENTITY_CLASS, entityClass.getName());
-		if (log.isDebugEnabled()) {
-			log.debug("Loading MongoDB data for {}", dbk);
-		}
-		mongoTemplate.execute(collName, new CollectionCallback<Object>() {
-			public Object doInCollection(MongoCollection<Document> collection) throws MongoException, DataAccessException {
-				for (Document dbo : collection.find(dbk)) {
-					String key = (String) dbo.get(ENTITY_FIELD_NAME);
-					if (log.isDebugEnabled()) {
-						log.debug("Processing key: {}", key);
-					}
-					if (!changeSet.getValues().containsKey(key)) {
-						String className = (String) dbo.get(ENTITY_FIELD_CLASS);
-						if (className == null) {
-							throw new DataIntegrityViolationException(
-									"Unble to convert property " + key + ": Invalid metadata, " + ENTITY_FIELD_CLASS + " not available");
-						}
-						Class<?> clazz = ClassUtils.resolveClassName(className, ClassUtils.getDefaultClassLoader());
-						Object value = mongoTemplate.getConverter().read(clazz, dbo);
-						if (log.isDebugEnabled()) {
-							log.debug("Adding to ChangeSet: {}", key);
-						}
-						changeSet.set(key, value);
-					}
-				}
-				return null;
-			}
-		});
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.crossstore.ChangeSetPersister#getPersistentId(org.springframework.data.crossstore.ChangeSetBacked, org.springframework.data.crossstore.ChangeSet)
-	 */
-	public Object getPersistentId(ChangeSetBacked entity, ChangeSet cs) throws DataAccessException {
-		if (log.isDebugEnabled()) {
-			log.debug("getPersistentId called on {}", entity);
-		}
-		if (entityManagerFactory == null) {
-			throw new DataAccessResourceFailureException("EntityManagerFactory cannot be null");
-		}
-
-		return entityManagerFactory.getPersistenceUnitUtil().getIdentifier(entity);
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.crossstore.ChangeSetPersister#persistState(org.springframework.data.crossstore.ChangeSetBacked, org.springframework.data.crossstore.ChangeSet)
-	 */
-	public Object persistState(ChangeSetBacked entity, ChangeSet cs) throws DataAccessException {
-		if (cs == null) {
-			log.debug("Flush: changeset was null, nothing to flush.");
-			return 0L;
-		}
-
-		if (log.isDebugEnabled()) {
-			log.debug("Flush: changeset: {}", cs.getValues());
-		}
-
-		String collName = getCollectionNameForEntity(entity.getClass());
-		if (mongoTemplate.getCollection(collName) == null) {
-			mongoTemplate.createCollection(collName);
-		}
-
-		for (String key : cs.getValues().keySet()) {
-			if (key != null && !key.startsWith("_") && !key.equals(ChangeSetPersister.ID_KEY)) {
-				Object value = cs.getValues().get(key);
-				final Document dbQuery = new Document();
-				dbQuery.put(ENTITY_ID, getPersistentId(entity, cs));
-				dbQuery.put(ENTITY_CLASS, entity.getClass().getName());
-				dbQuery.put(ENTITY_FIELD_NAME, key);
-				final Document dbId = mongoTemplate.execute(collName, new CollectionCallback<Document>() {
-					public Document doInCollection(MongoCollection<Document> collection)
-							throws MongoException, DataAccessException {
-						Document id = collection.find(dbQuery).first();
-						return id;
-					}
-				});
-
-				if (value == null) {
-					if (log.isDebugEnabled()) {
-						log.debug("Flush: removing: {}", dbQuery);
-					}
-					mongoTemplate.execute(collName, new CollectionCallback<Object>() {
-						public Object doInCollection(MongoCollection<Document> collection)
-								throws MongoException, DataAccessException {
-							DeleteResult dr = collection.deleteMany(dbQuery);
-							return null;
-						}
-					});
-				} else {
-					final Document dbDoc = new Document();
-					dbDoc.putAll(dbQuery);
-					if (log.isDebugEnabled()) {
-						log.debug("Flush: saving: {}", dbQuery);
-					}
-					mongoTemplate.getConverter().write(value, dbDoc);
-					dbDoc.put(ENTITY_FIELD_CLASS, value.getClass().getName());
-					if (dbId != null) {
-						dbDoc.put("_id", dbId.get("_id"));
-					}
-					mongoTemplate.execute(collName, new CollectionCallback<Object>() {
-						public Object doInCollection(MongoCollection<Document> collection)
-								throws MongoException, DataAccessException {
-
-							if (dbId != null) {
-								collection.replaceOne(Filters.eq("_id", dbId.get("_id")), dbDoc);
-							} else {
-
-								if (dbDoc.containsKey("_id") && dbDoc.get("_id") == null) {
-									dbDoc.remove("_id");
-								}
-								collection.insertOne(dbDoc);
-							}
-							return null;
-						}
-					});
-				}
-			}
-		}
-		return 0L;
-	}
-
-	/**
-	 * Returns the collection the given entity type shall be persisted to.
-	 *
-	 * @param entityClass must not be {@literal null}.
-	 * @return
-	 */
-	private String getCollectionNameForEntity(Class<? extends ChangeSetBacked> entityClass) {
-		return mongoTemplate.getCollectionName(entityClass);
-	}
-}

spring-data-mongodb-cross-store/src/main/java/org/springframework/data/mongodb/crossstore/MongoDocumentBacking.aj

@@ -1,272 +0,0 @@
-/*
- * Copyright 2011-2019 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore;
-
-import java.lang.reflect.Field;
-
-import javax.persistence.EntityManager;
-import javax.persistence.Transient;
-import javax.persistence.Entity;
-
-import org.aspectj.lang.JoinPoint;
-import org.aspectj.lang.reflect.FieldSignature;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.springframework.dao.DataAccessException;
-import org.springframework.data.mongodb.crossstore.RelatedDocument;
-import org.springframework.data.mongodb.crossstore.DocumentBacked;
-import org.springframework.data.crossstore.ChangeSetBackedTransactionSynchronization;
-import org.springframework.data.crossstore.ChangeSet;
-import org.springframework.data.crossstore.ChangeSetPersister;
-import org.springframework.data.crossstore.ChangeSetPersister.NotFoundException;
-import org.springframework.data.crossstore.HashMapChangeSet;
-import org.springframework.transaction.support.TransactionSynchronizationManager;
-
-/**
- * Aspect to turn an object annotated with @Document into a persistent document using Mongo.
- * 
- * @author Thomas Risberg
- * @deprecated will be removed without replacement.
- */
-@Deprecated
-public aspect MongoDocumentBacking {
-
-	private static final Logger LOGGER = LoggerFactory.getLogger(MongoDocumentBacking.class);
-
-	// Aspect shared config
-	private ChangeSetPersister<Object> changeSetPersister;
-
-	public void setChangeSetPersister(ChangeSetPersister<Object> changeSetPersister) {
-		this.changeSetPersister = changeSetPersister;
-	}
-
-	// ITD to introduce N state to Annotated objects
-	declare parents : (@Entity *) implements DocumentBacked;
-
-	// The annotated fields that will be persisted in MongoDB rather than with JPA
-	declare @field: @RelatedDocument * (@Entity+ *).*:@Transient;
-
-	// -------------------------------------------------------------------------
-	// Advise user-defined constructors of ChangeSetBacked objects to create a new
-	// backing ChangeSet
-	// -------------------------------------------------------------------------
-	pointcut arbitraryUserConstructorOfChangeSetBackedObject(DocumentBacked entity) : 
-		execution((DocumentBacked+).new(..)) &&
-		!execution((DocumentBacked+).new(ChangeSet)) &&
-		this(entity);
-
-	pointcut finderConstructorOfChangeSetBackedObject(DocumentBacked entity, ChangeSet cs) : 
-		execution((DocumentBacked+).new(ChangeSet)) &&
-		this(entity) && 
-		args(cs);
-
-	protected pointcut entityFieldGet(DocumentBacked entity) :
-        get(@RelatedDocument * DocumentBacked+.*) &&
-        this(entity) &&
-        !get(* DocumentBacked.*);
-
-	protected pointcut entityFieldSet(DocumentBacked entity, Object newVal) :
-        set(@RelatedDocument * DocumentBacked+.*) &&
-        this(entity) &&
-        args(newVal) &&
-        !set(* DocumentBacked.*);
-
-	// intercept EntityManager.merge calls
-	public pointcut entityManagerMerge(EntityManager em, Object entity) : 
-    call(* EntityManager.merge(Object)) &&
-    target(em) &&
-    args(entity);
-
-	// intercept EntityManager.remove calls
-	// public pointcut entityManagerRemove(EntityManager em, Object entity) :
-	// call(* EntityManager.remove(Object)) &&
-	// target(em) &&
-	// args(entity);
-
-	// move changeSet from detached entity to the newly merged persistent object
-	Object around(EntityManager em, Object entity) : entityManagerMerge(em, entity) {
-		Object mergedEntity = proceed(em, entity);
-		if (entity instanceof DocumentBacked && mergedEntity instanceof DocumentBacked) {
-			((DocumentBacked) mergedEntity).changeSet = ((DocumentBacked) entity).getChangeSet();
-		}
-		return mergedEntity;
-	}
-
-	// clear changeSet from removed entity
-	// Object around(EntityManager em, Object entity) : entityManagerRemove(em, entity) {
-	// if (entity instanceof DocumentBacked) {
-	// removeChangeSetValues((DocumentBacked)entity);
-	// }
-	// return proceed(em, entity);
-	// }
-
-	private static void removeChangeSetValues(DocumentBacked entity) {
-		LOGGER.debug("Removing all change-set values for " + entity);
-		ChangeSet nulledCs = new HashMapChangeSet();
-		DocumentBacked documentEntity = (DocumentBacked) entity;
-		@SuppressWarnings("unchecked")
-		ChangeSetPersister<Object> changeSetPersister = (ChangeSetPersister<Object>) documentEntity.itdChangeSetPersister;
-		try {
-			changeSetPersister.getPersistentState(documentEntity.getClass(), documentEntity.get_persistent_id(),
-					documentEntity.getChangeSet());
-		} catch (DataAccessException e) {
-		} catch (NotFoundException e) {
-		}
-		for (String key : entity.getChangeSet().getValues().keySet()) {
-			nulledCs.set(key, null);
-		}
-		entity.setChangeSet(nulledCs);
-	}
-
-	before(DocumentBacked entity) : arbitraryUserConstructorOfChangeSetBackedObject(entity) {
-		LOGGER.debug("User-defined constructor called on DocumentBacked object of class " + entity.getClass());
-		// Populate all ITD fields
-		entity.setChangeSet(new HashMapChangeSet());
-		entity.itdChangeSetPersister = changeSetPersister;
-		entity.itdTransactionSynchronization = new ChangeSetBackedTransactionSynchronization(changeSetPersister, entity);
-		// registerTransactionSynchronization(entity);
-	}
-
-	private static void registerTransactionSynchronization(DocumentBacked entity) {
-		if (TransactionSynchronizationManager.isSynchronizationActive()) {
-			if (!TransactionSynchronizationManager.getSynchronizations().contains(entity.itdTransactionSynchronization)) {
-				if (LOGGER.isDebugEnabled()) {
-					LOGGER.debug("Adding transaction synchronization for " + entity);
-				}
-				TransactionSynchronizationManager.registerSynchronization(entity.itdTransactionSynchronization);
-			} else {
-				if (LOGGER.isDebugEnabled()) {
-					LOGGER.debug("Transaction synchronization already active for " + entity);
-				}
-			}
-		} else {
-			if (LOGGER.isDebugEnabled()) {
-				LOGGER.debug("Transaction synchronization is not active for " + entity);
-			}
-		}
-	}
-
-	// -------------------------------------------------------------------------
-	// ChangeSet-related mixins
-	// -------------------------------------------------------------------------
-	// Introduced field
-	@Transient
-	private ChangeSet DocumentBacked.changeSet;
-
-	@Transient
-	private ChangeSetPersister<?> DocumentBacked.itdChangeSetPersister;
-
-	@Transient
-	private ChangeSetBackedTransactionSynchronization DocumentBacked.itdTransactionSynchronization;
-
-	public void DocumentBacked.setChangeSet(ChangeSet cs) {
-		this.changeSet = cs;
-	}
-
-	public ChangeSet DocumentBacked.getChangeSet() {
-		return changeSet;
-	}
-
-	// Flush the entity state to the persistent store
-	public void DocumentBacked.flush() {
-		Object id = itdChangeSetPersister.getPersistentId(this, this.changeSet);
-		itdChangeSetPersister.persistState(this, this.changeSet);
-	}
-
-	public Object DocumentBacked.get_persistent_id() {
-		return itdChangeSetPersister.getPersistentId(this, this.changeSet);
-	}
-
-	// lifecycle methods
-	@javax.persistence.PostPersist
-	public void DocumentBacked.itdPostPersist() {
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("JPA lifecycle event PrePersist: " + this.getClass().getName());
-		}
-		registerTransactionSynchronization(this);
-	}
-
-	@javax.persistence.PreUpdate
-	public void DocumentBacked.itdPreUpdate() {
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("JPA lifecycle event PreUpdate: " + this.getClass().getName() + " :: " + this);
-		}
-		registerTransactionSynchronization(this);
-	}
-
-	@javax.persistence.PostUpdate
-	public void DocumentBacked.itdPostUpdate() {
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("JPA lifecycle event PostUpdate: " + this.getClass().getName() + " :: " + this);
-		}
-		registerTransactionSynchronization(this);
-	}
-
-	@javax.persistence.PostRemove
-	public void DocumentBacked.itdPostRemove() {
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("JPA lifecycle event PostRemove: " + this.getClass().getName() + " :: " + this);
-		}
-		registerTransactionSynchronization(this);
-		removeChangeSetValues(this);
-	}
-
-	@javax.persistence.PostLoad
-	public void DocumentBacked.itdPostLoad() {
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("JPA lifecycle event PostLoad: " + this.getClass().getName() + " :: " + this);
-		}
-		registerTransactionSynchronization(this);
-	}
-
-	/**
-	 * delegates field reads to the state accessors instance
-	 */
-	Object around(DocumentBacked entity): entityFieldGet(entity) {
-		Field f = field(thisJoinPoint);
-		String propName = f.getName();
-		LOGGER.trace("GET " + f + " -> ChangeSet value property [" + propName + "] using: " + entity.getChangeSet());
-		if (entity.getChangeSet().getValues().get(propName) == null) {
-			try {
-				this.changeSetPersister
-						.getPersistentState(entity.getClass(), entity.get_persistent_id(), entity.getChangeSet());
-			} catch (NotFoundException e) {
-			}
-		}
-		Object fValue = entity.getChangeSet().getValues().get(propName);
-		if (fValue != null) {
-			return fValue;
-		}
-		return proceed(entity);
-	}
-
-	/**
-	 * delegates field writes to the state accessors instance
-	 */
-	Object around(DocumentBacked entity, Object newVal) : entityFieldSet(entity, newVal) {
-		Field f = field(thisJoinPoint);
-		String propName = f.getName();
-		LOGGER.trace("SET " + f + " -> ChangeSet number value property [" + propName + "] with value=[" + newVal + "]");
-		entity.getChangeSet().set(propName, newVal);
-		return proceed(entity, newVal);
-	}
-
-	Field field(JoinPoint joinPoint) {
-		FieldSignature fieldSignature = (FieldSignature) joinPoint.getSignature();
-		return fieldSignature.getField();
-	}
-}

spring-data-mongodb-cross-store/src/main/java/org/springframework/data/mongodb/crossstore/package-info.java

@@ -1,5 +0,0 @@
-/**
- * Infrastructure for Spring Data's MongoDB cross store support.
- */
-package org.springframework.data.mongodb.crossstore;
-

spring-data-mongodb-cross-store/src/test/java/org/springframework/data/mongodb/crossstore/CrossStoreMongoTests.java

@@ -1,195 +0,0 @@
-/*
- * Copyright 2011-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore;
-
-import javax.persistence.EntityManager;
-import javax.persistence.PersistenceContext;
-
-import org.bson.Document;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.data.mongodb.core.MongoTemplate;
-import org.springframework.data.mongodb.crossstore.test.Address;
-import org.springframework.data.mongodb.crossstore.test.Person;
-import org.springframework.data.mongodb.crossstore.test.Resume;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-import org.springframework.transaction.PlatformTransactionManager;
-import org.springframework.transaction.TransactionStatus;
-import org.springframework.transaction.annotation.Transactional;
-import org.springframework.transaction.support.TransactionCallback;
-import org.springframework.transaction.support.TransactionTemplate;
-
-/**
- * Integration tests for MongoDB cross-store persistence (mainly {@link MongoChangeSetPersister}).
- *
- * @author Thomas Risberg
- * @author Oliver Gierke
- */
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration("classpath:/META-INF/spring/applicationContext.xml")
-public class CrossStoreMongoTests {
-
-	@Autowired MongoTemplate mongoTemplate;
-
-	@PersistenceContext EntityManager entityManager;
-
-	@Autowired PlatformTransactionManager transactionManager;
-	TransactionTemplate txTemplate;
-
-	@Before
-	public void setUp() {
-
-		txTemplate = new TransactionTemplate(transactionManager);
-
-		clearData(Person.class);
-
-		Address address = new Address(12, "MAin St.", "Boston", "MA", "02101");
-
-		Resume resume = new Resume();
-		resume.addEducation("Skanstulls High School, 1975");
-		resume.addEducation("Univ. of Stockholm, 1980");
-		resume.addJob("DiMark, DBA, 1990-2000");
-		resume.addJob("VMware, Developer, 2007-");
-
-		final Person person = new Person("Thomas", 20);
-		person.setAddress(address);
-		person.setResume(resume);
-		person.setId(1L);
-
-		txTemplate.execute(new TransactionCallback<Void>() {
-			public Void doInTransaction(TransactionStatus status) {
-				entityManager.persist(person);
-				return null;
-			}
-		});
-	}
-
-	@After
-	public void tearDown() {
-		txTemplate.execute(new TransactionCallback<Void>() {
-			public Void doInTransaction(TransactionStatus status) {
-				entityManager.remove(entityManager.find(Person.class, 1L));
-				return null;
-			}
-		});
-	}
-
-	private void clearData(Class<?> domainType) {
-
-		String collectionName = mongoTemplate.getCollectionName(domainType);
-		mongoTemplate.dropCollection(collectionName);
-	}
-
-	@Test
-	@Transactional
-	public void testReadJpaToMongoEntityRelationship() {
-
-		Person found = entityManager.find(Person.class, 1L);
-		Assert.assertNotNull(found);
-		Assert.assertEquals(Long.valueOf(1), found.getId());
-		Assert.assertNotNull(found);
-		Assert.assertEquals(Long.valueOf(1), found.getId());
-		Assert.assertNotNull(found.getResume());
-		Assert.assertEquals("DiMark, DBA, 1990-2000" + "; " + "VMware, Developer, 2007-", found.getResume().getJobs());
-	}
-
-	@Test
-	@Transactional
-	public void testUpdatedJpaToMongoEntityRelationship() {
-
-		Person found = entityManager.find(Person.class, 1L);
-		found.setAge(44);
-		found.getResume().addJob("SpringDeveloper.com, Consultant, 2005-2006");
-
-		entityManager.merge(found);
-
-		Assert.assertNotNull(found);
-		Assert.assertEquals(Long.valueOf(1), found.getId());
-		Assert.assertNotNull(found);
-		Assert.assertEquals(Long.valueOf(1), found.getId());
-		Assert.assertNotNull(found.getResume());
-		Assert.assertEquals("DiMark, DBA, 1990-2000" + "; " + "VMware, Developer, 2007-" + "; "
-				+ "SpringDeveloper.com, Consultant, 2005-2006", found.getResume().getJobs());
-	}
-
-	@Test
-	public void testMergeJpaEntityWithMongoDocument() {
-
-		final Person detached = entityManager.find(Person.class, 1L);
-		entityManager.detach(detached);
-		detached.getResume().addJob("TargetRx, Developer, 2000-2005");
-
-		Person merged = txTemplate.execute(new TransactionCallback<Person>() {
-			public Person doInTransaction(TransactionStatus status) {
-				Person result = entityManager.merge(detached);
-				entityManager.flush();
-				return result;
-			}
-		});
-
-		Assert.assertTrue(detached.getResume().getJobs().contains("TargetRx, Developer, 2000-2005"));
-		Assert.assertTrue(merged.getResume().getJobs().contains("TargetRx, Developer, 2000-2005"));
-		final Person updated = entityManager.find(Person.class, 1L);
-		Assert.assertTrue(updated.getResume().getJobs().contains("TargetRx, Developer, 2000-2005"));
-	}
-
-	@Test
-	public void testRemoveJpaEntityWithMongoDocument() {
-
-		txTemplate.execute(new TransactionCallback<Person>() {
-			public Person doInTransaction(TransactionStatus status) {
-				Person p2 = new Person("Thomas", 20);
-				Resume r2 = new Resume();
-				r2.addEducation("Skanstulls High School, 1975");
-				r2.addJob("DiMark, DBA, 1990-2000");
-				p2.setResume(r2);
-				p2.setId(2L);
-				entityManager.persist(p2);
-				Person p3 = new Person("Thomas", 20);
-				Resume r3 = new Resume();
-				r3.addEducation("Univ. of Stockholm, 1980");
-				r3.addJob("VMware, Developer, 2007-");
-				p3.setResume(r3);
-				p3.setId(3L);
-				entityManager.persist(p3);
-				return null;
-			}
-		});
-		txTemplate.execute(new TransactionCallback<Person>() {
-			public Person doInTransaction(TransactionStatus status) {
-				final Person found2 = entityManager.find(Person.class, 2L);
-				entityManager.remove(found2);
-				return null;
-			}
-		});
-
-		boolean weFound3 = false;
-
-		for (Document dbo : this.mongoTemplate.getCollection(mongoTemplate.getCollectionName(Person.class)).find()) {
-			Assert.assertTrue(!dbo.get("_entity_id").equals(2L));
-			if (dbo.get("_entity_id").equals(3L)) {
-				weFound3 = true;
-			}
-		}
-		Assert.assertTrue(weFound3);
-	}
-
-}

spring-data-mongodb-cross-store/src/test/java/org/springframework/data/mongodb/crossstore/test/Address.java

@@ -1,75 +0,0 @@
-/*
- * Copyright 2011-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore.test;
-
-public class Address {
-
-	private Integer streetNumber;
-	private String streetName;
-	private String city;
-	private String state;
-	private String zip;
-
-	public Address(Integer streetNumber, String streetName, String city, String state, String zip) {
-		super();
-		this.streetNumber = streetNumber;
-		this.streetName = streetName;
-		this.city = city;
-		this.state = state;
-		this.zip = zip;
-	}
-
-	public Integer getStreetNumber() {
-		return streetNumber;
-	}
-
-	public void setStreetNumber(Integer streetNumber) {
-		this.streetNumber = streetNumber;
-	}
-
-	public String getStreetName() {
-		return streetName;
-	}
-
-	public void setStreetName(String streetName) {
-		this.streetName = streetName;
-	}
-
-	public String getCity() {
-		return city;
-	}
-
-	public void setCity(String city) {
-		this.city = city;
-	}
-
-	public String getState() {
-		return state;
-	}
-
-	public void setState(String state) {
-		this.state = state;
-	}
-
-	public String getZip() {
-		return zip;
-	}
-
-	public void setZip(String zip) {
-		this.zip = zip;
-	}
-
-}

spring-data-mongodb-cross-store/src/test/java/org/springframework/data/mongodb/crossstore/test/Person.java

@@ -1,102 +0,0 @@
-/*
- * Copyright 2011-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore.test;
-
-import javax.persistence.Entity;
-import javax.persistence.Id;
-
-import org.springframework.data.mongodb.crossstore.RelatedDocument;
-
-@Entity
-public class Person {
-
-	@Id
-	Long id;
-
-	private String name;
-
-	private int age;
-
-	private java.util.Date birthDate;
-
-	@RelatedDocument
-	private Address address;
-
-	@RelatedDocument
-	private Resume resume;
-
-	public Person() {
-	}
-
-	public Person(String name, int age) {
-		this.name = name;
-		this.age = age;
-		this.birthDate = new java.util.Date();
-	}
-
-	public void birthday() {
-		++age;
-	}
-
-	public Long getId() {
-		return id;
-	}
-
-	public void setId(Long id) {
-		this.id = id;
-	}
-
-	public String getName() {
-		return name;
-	}
-
-	public void setName(String name) {
-		this.name = name;
-	}
-
-	public int getAge() {
-		return age;
-	}
-
-	public void setAge(int age) {
-		this.age = age;
-	}
-
-	public java.util.Date getBirthDate() {
-		return birthDate;
-	}
-
-	public void setBirthDate(java.util.Date birthDate) {
-		this.birthDate = birthDate;
-	}
-
-	public Resume getResume() {
-		return resume;
-	}
-
-	public void setResume(Resume resume) {
-		this.resume = resume;
-	}
-
-	public Address getAddress() {
-		return address;
-	}
-
-	public void setAddress(Address address) {
-		this.address = address;
-	}
-
-}

spring-data-mongodb-cross-store/src/test/java/org/springframework/data/mongodb/crossstore/test/Resume.java

@@ -1,63 +0,0 @@
-/*
- * Copyright 2011-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.crossstore.test;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.bson.types.ObjectId;
-import org.springframework.data.annotation.Id;
-import org.springframework.data.mongodb.core.mapping.Document;
-
-@Document
-public class Resume {
-
-	private static final Log LOGGER = LogFactory.getLog(Resume.class);
-
-	@Id
-	private ObjectId id;
-
-	private String education = "";
-
-	private String jobs = "";
-
-	public String getId() {
-		return id.toString();
-	}
-
-	public String getEducation() {
-		return education;
-	}
-
-	public void addEducation(String education) {
-		LOGGER.debug("Adding education " + education);
-		this.education = this.education + (this.education.length() > 0 ? "; " : "") + education;
-	}
-
-	public String getJobs() {
-		return jobs;
-	}
-
-	public void addJob(String job) {
-		LOGGER.debug("Adding job " + job);
-		this.jobs = this.jobs + (this.jobs.length() > 0 ? "; " : "") + job;
-	}
-
-	@Override
-	public String toString() {
-		return "Resume [education=" + education + ", jobs=" + jobs + "]";
-	}
-
-}

spring-data-mongodb-cross-store/src/test/resources/META-INF/persistence.xml

@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-             version="2.0"
-             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
-  <persistence-unit name="test" transaction-type="RESOURCE_LOCAL">
-    <provider>org.hibernate.ejb.HibernatePersistence</provider>
-    <class>org.springframework.data.mongodb.crossstore.test.Person</class>
-    <properties>
-      <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
-      <!--value='create' to build a new database on each run; value='update' to modify an existing database; value='create-drop' means the same as 'create' but also drops tables when Hibernate closes; value='validate' makes no changes to the database-->
-      <property name="hibernate.hbm2ddl.auto" value="update"/>
-      <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.ImprovedNamingStrategy"/>
-    </properties>
-  </persistence-unit>
-</persistence>

spring-data-mongodb-cross-store/src/test/resources/META-INF/spring/applicationContext.xml

@@ -1,72 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<beans xmlns="http://www.springframework.org/schema/beans"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xmlns:tx="http://www.springframework.org/schema/tx"
-	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
-	xmlns:context="http://www.springframework.org/schema/context"
-	xmlns:mongo="http://www.springframework.org/schema/data/mongo"
-	xsi:schemaLocation="http://www.springframework.org/schema/data/mongo https://www.springframework.org/schema/data/mongo/spring-mongo.xsd
-		http://www.springframework.org/schema/jdbc https://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
-		http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans-3.0.xsd
-		http://www.springframework.org/schema/tx https://www.springframework.org/schema/tx/spring-tx-3.0.xsd
-		http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context-3.0.xsd">
-
-  <context:spring-configured/>
-
-  <context:component-scan base-package="org.springframework.persistence.mongodb.test">
-    <context:exclude-filter expression="org.springframework.stereotype.Controller" type="annotation"/>
-  </context:component-scan>
-
-  <mongo:mapping-converter/>
-  
-  <!--  Mongo config -->
-  <bean id="mongoClient" class="org.springframework.data.mongodb.core.MongoClientFactoryBean">
-    <property name="host" value="localhost"/>
-    <property name="port" value="27017"/>
-  </bean>
-
-  <bean id="mongoDbFactory" class="org.springframework.data.mongodb.core.SimpleMongoDbFactory">
-  	<constructor-arg name="mongoClient" ref="mongoClient"/>
-  	<constructor-arg name="databaseName" value="database"/>
-  </bean>
-
-  <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">
-    <constructor-arg name="mongoDbFactory" ref="mongoDbFactory"/>
-    <constructor-arg name="mongoConverter" ref="mappingConverter"/>
-  </bean>
-
-  <bean class="org.springframework.data.mongodb.core.MongoExceptionTranslator"/>
-
-  <!--  Mongo aspect config -->
-  <bean class="org.springframework.data.mongodb.crossstore.MongoDocumentBacking"
-        factory-method="aspectOf">
-    <property name="changeSetPersister" ref="mongoChangeSetPersister"/>
-  </bean>
-  <bean id="mongoChangeSetPersister" 
-      class="org.springframework.data.mongodb.crossstore.MongoChangeSetPersister">
-    <property name="mongoTemplate" ref="mongoTemplate"/>
-    <property name="entityManagerFactory" ref="entityManagerFactory"/>
-  </bean>
-
-  <jdbc:embedded-database id="dataSource" type="HSQL">
-  </jdbc:embedded-database>
-
-  <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
-    <property name="entityManagerFactory" ref="entityManagerFactory"/>
-  </bean>
-
-  <tx:annotation-driven mode="aspectj" transaction-manager="transactionManager"/>
-
-  <bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
-    <property name="persistenceUnitName" value="test"/>
-    <property name="dataSource" ref="dataSource"/>
-    <property name="jpaVendorAdapter">
-      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
-        <property name="showSql" value="true"/>
-        <property name="generateDdl" value="true"/>
-        <property name="databasePlatform" value="org.hibernate.dialect.HSQLDialect"/>
-      </bean>
-    </property>
-  </bean>
-
-</beans>

spring-data-mongodb-cross-store/src/test/resources/logback.xml

@@ -1,18 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<configuration>
-
-	<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
-		<encoder>
-			<pattern>%d %5p %40.40c:%4L - %m%n</pattern>
-		</encoder>
-	</appender>
-
-	<!-- 
-	<logger name="org.springframework" level="debug" />
-	 -->
-
-	<root level="error">
-		<appender-ref ref="console" />
-	</root>
-
-</configuration>

spring-data-mongodb-distribution/pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 
 	<modelVersion>4.0.0</modelVersion>
 
@@ -13,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.1.22.BUILD-SNAPSHOT</version>
+		<version>3.0.0.M2</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -31,8 +32,15 @@
 			<plugin>
 				<groupId>org.asciidoctor</groupId>
 				<artifactId>asciidoctor-maven-plugin</artifactId>
+				<configuration>
+					<attributes>
+						<mongo-reactivestreams>${mongo.reactivestreams}</mongo-reactivestreams>
+						<reactor>${reactor}</reactor>
+					</attributes>
+				</configuration>
 			</plugin>
 		</plugins>
+
 	</build>
 
 </project>

spring-data-mongodb/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.1.22.BUILD-SNAPSHOT</version>
+		<version>3.0.0.M2</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -83,14 +83,14 @@
 
 		<!-- reactive -->
 		<dependency>
-		 	<groupId>org.mongodb</groupId>
+			<groupId>org.mongodb</groupId>
 			<artifactId>mongodb-driver-reactivestreams</artifactId>
 			<version>${mongo.reactivestreams}</version>
 			<optional>true</optional>
 		</dependency>
 
 		<dependency>
-		 	<groupId>org.mongodb</groupId>
+			<groupId>org.mongodb</groupId>
 			<artifactId>mongodb-driver-async</artifactId>
 			<version>${mongo}</version>
 			<optional>true</optional>
@@ -107,7 +107,7 @@
 		</dependency>
 
 		<dependency>
-		 	<groupId>io.projectreactor</groupId>
+			<groupId>io.projectreactor</groupId>
 			<artifactId>reactor-core</artifactId>
 			<optional>true</optional>
 		</dependency>
@@ -119,14 +119,14 @@
 		</dependency>
 
 		<dependency>
-		 	<groupId>io.reactivex</groupId>
+			<groupId>io.reactivex</groupId>
 			<artifactId>rxjava</artifactId>
 			<version>${rxjava}</version>
 			<optional>true</optional>
 		</dependency>
 
 		<dependency>
-		 	<groupId>io.reactivex</groupId>
+			<groupId>io.reactivex</groupId>
 			<artifactId>rxjava-reactive-streams</artifactId>
 			<version>${rxjava-reactive-streams}</version>
 			<optional>true</optional>
@@ -264,20 +264,25 @@
 		<dependency>
 			<groupId>org.jetbrains.kotlin</groupId>
 			<artifactId>kotlin-stdlib</artifactId>
-			<version>${kotlin}</version>
 			<optional>true</optional>
 		</dependency>
+
 		<dependency>
 			<groupId>org.jetbrains.kotlin</groupId>
 			<artifactId>kotlin-reflect</artifactId>
-			<version>${kotlin}</version>
 			<optional>true</optional>
 		</dependency>
+
 		<dependency>
-			<groupId>org.jetbrains.kotlin</groupId>
-			<artifactId>kotlin-test</artifactId>
-			<version>${kotlin}</version>
-			<scope>test</scope>
+			<groupId>org.jetbrains.kotlinx</groupId>
+			<artifactId>kotlinx-coroutines-core</artifactId>
+			<optional>true</optional>
+		</dependency>
+
+		<dependency>
+			<groupId>org.jetbrains.kotlinx</groupId>
+			<artifactId>kotlinx-coroutines-reactor</artifactId>
+			<optional>true</optional>
 		</dependency>
 
 		<dependency>
@@ -322,6 +327,7 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
 				<configuration>
+					<useSystemClassLoader>false</useSystemClassLoader>
 					<useFile>false</useFile>
 					<includes>
 						<include>**/*Tests.java</include>

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/CannotGetMongoDbConnectionException.java

@@ -1,69 +0,0 @@
-/*
- * Copyright 2010-2020 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb;
-
-import org.springframework.dao.DataAccessResourceFailureException;
-import org.springframework.data.authentication.UserCredentials;
-import org.springframework.lang.Nullable;
-
-/**
- * Exception being thrown in case we cannot connect to a MongoDB instance.
- *
- * @author Oliver Gierke
- * @author Mark Paluch
- */
-public class CannotGetMongoDbConnectionException extends DataAccessResourceFailureException {
-
-	private final UserCredentials credentials;
-	private final @Nullable String database;
-
-	private static final long serialVersionUID = 1172099106475265589L;
-
-	public CannotGetMongoDbConnectionException(String msg, Throwable cause) {
-		super(msg, cause);
-		this.database = null;
-		this.credentials = UserCredentials.NO_CREDENTIALS;
-	}
-
-	public CannotGetMongoDbConnectionException(String msg) {
-		this(msg, null, UserCredentials.NO_CREDENTIALS);
-	}
-
-	public CannotGetMongoDbConnectionException(String msg, @Nullable String database, UserCredentials credentials) {
-		super(msg);
-		this.database = database;
-		this.credentials = credentials;
-	}
-
-	/**
-	 * Returns the {@link UserCredentials} that were used when trying to connect to the MongoDB instance.
-	 *
-	 * @return
-	 */
-	public UserCredentials getCredentials() {
-		return this.credentials;
-	}
-
-	/**
-	 * Returns the name of the database trying to be accessed.
-	 *
-	 * @return
-	 */
-	@Nullable
-	public String getDatabase() {
-		return database;
-	}
-}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoDatabaseFactory.java

@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.springframework.data.mongodb;
 
 import reactor.core.publisher.Mono;
@@ -88,4 +87,16 @@ public interface ReactiveMongoDatabaseFactory extends CodecRegistryProvider {
 	 * @since 2.1
 	 */
 	ReactiveMongoDatabaseFactory withSession(ClientSession session);
+
+	/**
+	 * Returns if the given {@link ReactiveMongoDatabaseFactory} is bound to a
+	 * {@link com.mongodb.reactivestreams.client.ClientSession} that has an
+	 * {@link com.mongodb.reactivestreams.client.ClientSession#hasActiveTransaction() active transaction}.
+	 *
+	 * @return {@literal true} if there's an active transaction, {@literal false} otherwise.
+	 * @since 2.2
+	 */
+	default boolean isTransactionActive() {
+		return false;
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoDatabaseUtils.java

@@ -0,0 +1,278 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb;
+
+import reactor.core.publisher.Mono;
+import reactor.util.context.Context;
+
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.NoTransactionException;
+import org.springframework.transaction.reactive.ReactiveResourceSynchronization;
+import org.springframework.transaction.reactive.TransactionSynchronization;
+import org.springframework.transaction.reactive.TransactionSynchronizationManager;
+import org.springframework.transaction.support.ResourceHolderSynchronization;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.reactivestreams.client.ClientSession;
+import com.mongodb.reactivestreams.client.MongoCollection;
+import com.mongodb.reactivestreams.client.MongoDatabase;
+
+/**
+ * Helper class for managing reactive {@link MongoDatabase} instances via {@link ReactiveMongoDatabaseFactory}. Used for
+ * obtaining {@link ClientSession session bound} resources, such as {@link MongoDatabase} and {@link MongoCollection}
+ * suitable for transactional usage.
+ * <p />
+ * <strong>Note:</strong> Intended for internal usage only.
+ *
+ * @author Mark Paluch
+ * @author Christoph Strobl
+ * @since 2.2
+ */
+public class ReactiveMongoDatabaseUtils {
+
+	/**
+	 * Check if the {@link ReactiveMongoDatabaseFactory} is actually bound to a
+	 * {@link com.mongodb.reactivestreams.client.ClientSession} that has an active transaction, or if a
+	 * {@link org.springframework.transaction.reactive.TransactionSynchronization} has been registered for the
+	 * {@link ReactiveMongoDatabaseFactory resource} and if the associated
+	 * {@link com.mongodb.reactivestreams.client.ClientSession} has an
+	 * {@link com.mongodb.reactivestreams.client.ClientSession#hasActiveTransaction() active transaction}.
+	 *
+	 * @param databaseFactory the resource to check transactions for. Must not be {@literal null}.
+	 * @return a {@link Mono} emitting {@literal true} if the factory has an ongoing transaction.
+	 */
+	public static Mono<Boolean> isTransactionActive(ReactiveMongoDatabaseFactory databaseFactory) {
+
+		if (databaseFactory.isTransactionActive()) {
+			return Mono.just(true);
+		}
+
+		return TransactionSynchronizationManager.forCurrentTransaction() //
+				.map(it -> {
+
+					ReactiveMongoResourceHolder holder = (ReactiveMongoResourceHolder) it.getResource(databaseFactory);
+					return holder != null && holder.hasActiveTransaction();
+				}) //
+				.onErrorResume(NoTransactionException.class, e -> Mono.just(false));
+	}
+
+	/**
+	 * Obtain the default {@link MongoDatabase database} form the given {@link ReactiveMongoDatabaseFactory factory} using
+	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
+	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param factory the {@link ReactiveMongoDatabaseFactory} to get the {@link MongoDatabase} from.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static Mono<MongoDatabase> getDatabase(ReactiveMongoDatabaseFactory factory) {
+		return doGetMongoDatabase(null, factory, SessionSynchronization.ON_ACTUAL_TRANSACTION);
+	}
+
+	/**
+	 * Obtain the default {@link MongoDatabase database} form the given {@link ReactiveMongoDatabaseFactory factory}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
+	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param factory the {@link ReactiveMongoDatabaseFactory} to get the {@link MongoDatabase} from.
+	 * @param sessionSynchronization the synchronization to use. Must not be {@literal null}.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static Mono<MongoDatabase> getDatabase(ReactiveMongoDatabaseFactory factory,
+			SessionSynchronization sessionSynchronization) {
+		return doGetMongoDatabase(null, factory, sessionSynchronization);
+	}
+
+	/**
+	 * Obtain the {@link MongoDatabase database} with given name form the given {@link ReactiveMongoDatabaseFactory
+	 * factory} using {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
+	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param dbName the name of the {@link MongoDatabase} to get.
+	 * @param factory the {@link ReactiveMongoDatabaseFactory} to get the {@link MongoDatabase} from.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static Mono<MongoDatabase> getDatabase(String dbName, ReactiveMongoDatabaseFactory factory) {
+		return doGetMongoDatabase(dbName, factory, SessionSynchronization.ON_ACTUAL_TRANSACTION);
+	}
+
+	/**
+	 * Obtain the {@link MongoDatabase database} with given name form the given {@link ReactiveMongoDatabaseFactory
+	 * factory}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
+	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param dbName the name of the {@link MongoDatabase} to get.
+	 * @param factory the {@link ReactiveMongoDatabaseFactory} to get the {@link MongoDatabase} from.
+	 * @param sessionSynchronization the synchronization to use. Must not be {@literal null}.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static Mono<MongoDatabase> getDatabase(String dbName, ReactiveMongoDatabaseFactory factory,
+			SessionSynchronization sessionSynchronization) {
+		return doGetMongoDatabase(dbName, factory, sessionSynchronization);
+	}
+
+	private static Mono<MongoDatabase> doGetMongoDatabase(@Nullable String dbName, ReactiveMongoDatabaseFactory factory,
+			SessionSynchronization sessionSynchronization) {
+
+		Assert.notNull(factory, "DatabaseFactory must not be null!");
+
+		return TransactionSynchronizationManager.forCurrentTransaction()
+				.filter(TransactionSynchronizationManager::isSynchronizationActive) //
+				.flatMap(synchronizationManager -> {
+
+					return doGetSession(synchronizationManager, factory, sessionSynchronization) //
+							.map(it -> getMongoDatabaseOrDefault(dbName, factory.withSession(it)));
+				})
+				.onErrorResume(NoTransactionException.class,
+						e -> Mono.fromSupplier(() -> getMongoDatabaseOrDefault(dbName, factory)))
+				.defaultIfEmpty(getMongoDatabaseOrDefault(dbName, factory));
+	}
+
+	private static MongoDatabase getMongoDatabaseOrDefault(@Nullable String dbName,
+			ReactiveMongoDatabaseFactory factory) {
+		return StringUtils.hasText(dbName) ? factory.getMongoDatabase(dbName) : factory.getMongoDatabase();
+	}
+
+	private static Mono<ClientSession> doGetSession(TransactionSynchronizationManager synchronizationManager,
+			ReactiveMongoDatabaseFactory dbFactory, SessionSynchronization sessionSynchronization) {
+
+		final ReactiveMongoResourceHolder registeredHolder = (ReactiveMongoResourceHolder) synchronizationManager
+				.getResource(dbFactory);
+
+		// check for native MongoDB transaction
+		if (registeredHolder != null
+				&& (registeredHolder.hasSession() || registeredHolder.isSynchronizedWithTransaction())) {
+
+			return registeredHolder.hasSession() ? Mono.just(registeredHolder.getSession())
+					: createClientSession(dbFactory).map(registeredHolder::setSessionIfAbsent);
+		}
+
+		if (SessionSynchronization.ON_ACTUAL_TRANSACTION.equals(sessionSynchronization)) {
+			return Mono.empty();
+		}
+
+		// init a non native MongoDB transaction by registering a MongoSessionSynchronization
+		return createClientSession(dbFactory).map(session -> {
+
+			ReactiveMongoResourceHolder newHolder = new ReactiveMongoResourceHolder(session, dbFactory);
+			newHolder.getRequiredSession().startTransaction();
+
+			synchronizationManager
+					.registerSynchronization(new MongoSessionSynchronization(synchronizationManager, newHolder, dbFactory));
+			newHolder.setSynchronizedWithTransaction(true);
+			synchronizationManager.bindResource(dbFactory, newHolder);
+
+			return newHolder.getSession();
+		});
+	}
+
+	private static Mono<ClientSession> createClientSession(ReactiveMongoDatabaseFactory dbFactory) {
+		return dbFactory.getSession(ClientSessionOptions.builder().causallyConsistent(true).build());
+	}
+
+	/**
+	 * MongoDB specific {@link ResourceHolderSynchronization} for resource cleanup at the end of a transaction when
+	 * participating in a non-native MongoDB transaction, such as a R2CBC transaction.
+	 *
+	 * @author Mark Paluch
+	 * @since 2.2
+	 */
+	private static class MongoSessionSynchronization
+			extends ReactiveResourceSynchronization<ReactiveMongoResourceHolder, Object> {
+
+		private final ReactiveMongoResourceHolder resourceHolder;
+
+		MongoSessionSynchronization(TransactionSynchronizationManager synchronizationManager,
+				ReactiveMongoResourceHolder resourceHolder, ReactiveMongoDatabaseFactory dbFactory) {
+
+			super(resourceHolder, dbFactory, synchronizationManager);
+			this.resourceHolder = resourceHolder;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#shouldReleaseBeforeCompletion()
+		 */
+		@Override
+		protected boolean shouldReleaseBeforeCompletion() {
+			return false;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#processResourceAfterCommit(java.lang.Object)
+		 */
+		@Override
+		protected Mono<Void> processResourceAfterCommit(ReactiveMongoResourceHolder resourceHolder) {
+
+			if (isTransactionActive(resourceHolder)) {
+				return Mono.from(resourceHolder.getRequiredSession().commitTransaction());
+			}
+
+			return Mono.empty();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#afterCompletion(int)
+		 */
+		@Override
+		public Mono<Void> afterCompletion(int status) {
+
+			return Mono.defer(() -> {
+
+				if (status == TransactionSynchronization.STATUS_ROLLED_BACK && isTransactionActive(this.resourceHolder)) {
+
+					return Mono.from(resourceHolder.getRequiredSession().abortTransaction()) //
+							.then(super.afterCompletion(status));
+				}
+
+				return super.afterCompletion(status);
+			});
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#releaseResource(java.lang.Object, java.lang.Object)
+		 */
+		@Override
+		protected Mono<Void> releaseResource(ReactiveMongoResourceHolder resourceHolder, Object resourceKey) {
+
+			return Mono.fromRunnable(() -> {
+				if (resourceHolder.hasActiveSession()) {
+					resourceHolder.getRequiredSession().close();
+				}
+			});
+		}
+
+		private boolean isTransactionActive(ReactiveMongoResourceHolder resourceHolder) {
+
+			if (!resourceHolder.hasSession()) {
+				return false;
+			}
+
+			return resourceHolder.getRequiredSession().hasActiveTransaction();
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoResourceHolder.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb;
+
+import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.support.ResourceHolderSupport;
+
+import com.mongodb.reactivestreams.client.ClientSession;
+
+/**
+ * MongoDB specific resource holder, wrapping a {@link ClientSession}. {@link ReactiveMongoTransactionManager} binds
+ * instances of this class to the subscriber context.
+ * <p />
+ * <strong>Note:</strong> Intended for internal usage only.
+ *
+ * @author Mark Paluch
+ * @author Christoph Strobl
+ * @since 2.2
+ * @see ReactiveMongoTransactionManager
+ * @see ReactiveMongoTemplate
+ */
+class ReactiveMongoResourceHolder extends ResourceHolderSupport {
+
+	private @Nullable ClientSession session;
+	private ReactiveMongoDatabaseFactory databaseFactory;
+
+	/**
+	 * Create a new {@link ReactiveMongoResourceHolder} for a given {@link ClientSession session}.
+	 *
+	 * @param session the associated {@link ClientSession}. Can be {@literal null}.
+	 * @param databaseFactory the associated {@link MongoDbFactory}. must not be {@literal null}.
+	 */
+	ReactiveMongoResourceHolder(@Nullable ClientSession session, ReactiveMongoDatabaseFactory databaseFactory) {
+
+		this.session = session;
+		this.databaseFactory = databaseFactory;
+	}
+
+	/**
+	 * @return the associated {@link ClientSession}. Can be {@literal null}.
+	 */
+	@Nullable
+	ClientSession getSession() {
+		return session;
+	}
+
+	/**
+	 * @return the required associated {@link ClientSession}.
+	 * @throws IllegalStateException if no session is associated.
+	 */
+	ClientSession getRequiredSession() {
+
+		ClientSession session = getSession();
+
+		if (session == null) {
+			throw new IllegalStateException("No ClientSession associated");
+		}
+		return session;
+	}
+
+	/**
+	 * @return the associated {@link ReactiveMongoDatabaseFactory}.
+	 */
+	public ReactiveMongoDatabaseFactory getDatabaseFactory() {
+		return databaseFactory;
+	}
+
+	/**
+	 * Set the {@link ClientSession} to guard.
+	 *
+	 * @param session can be {@literal null}.
+	 */
+	public void setSession(@Nullable ClientSession session) {
+		this.session = session;
+	}
+
+	/**
+	 * @return {@literal true} if session is not {@literal null}.
+	 */
+	boolean hasSession() {
+		return session != null;
+	}
+
+	/**
+	 * If the {@link ReactiveMongoResourceHolder} is {@link #hasSession() not already associated} with a
+	 * {@link ClientSession} the given value is {@link #setSession(ClientSession) set} and returned, otherwise the current
+	 * bound session is returned.
+	 * 
+	 * @param session
+	 * @return
+	 */
+	@Nullable
+	public ClientSession setSessionIfAbsent(@Nullable ClientSession session) {
+
+		if (!hasSession()) {
+			setSession(session);
+		}
+
+		return session;
+	}
+
+	/**
+	 * @return {@literal true} if the session is active and has not been closed.
+	 */
+	boolean hasActiveSession() {
+
+		if (!hasSession()) {
+			return false;
+		}
+
+		return hasServerSession() && !getRequiredSession().getServerSession().isClosed();
+	}
+
+	/**
+	 * @return {@literal true} if the session has an active transaction.
+	 * @see #hasActiveSession()
+	 */
+	boolean hasActiveTransaction() {
+
+		if (!hasActiveSession()) {
+			return false;
+		}
+
+		return getRequiredSession().hasActiveTransaction();
+	}
+
+	/**
+	 * @return {@literal true} if the {@link ClientSession} has a {@link com.mongodb.session.ServerSession} associated
+	 *         that is accessible via {@link ClientSession#getServerSession()}.
+	 */
+	boolean hasServerSession() {
+
+		try {
+			return getRequiredSession().getServerSession() != null;
+		} catch (IllegalStateException serverSessionClosed) {
+			// ignore
+		}
+
+		return false;
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoTransactionManager.java

@@ -0,0 +1,530 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.TransactionDefinition;
+import org.springframework.transaction.TransactionException;
+import org.springframework.transaction.TransactionSystemException;
+import org.springframework.transaction.reactive.AbstractReactiveTransactionManager;
+import org.springframework.transaction.reactive.GenericReactiveTransaction;
+import org.springframework.transaction.reactive.TransactionSynchronizationManager;
+import org.springframework.transaction.support.SmartTransactionObject;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.MongoException;
+import com.mongodb.TransactionOptions;
+import com.mongodb.reactivestreams.client.ClientSession;
+
+/**
+ * A {@link org.springframework.transaction.ReactiveTransactionManager} implementation that manages
+ * {@link com.mongodb.reactivestreams.client.ClientSession} based transactions for a single
+ * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory}.
+ * <p />
+ * Binds a {@link ClientSession} from the specified
+ * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory} to the subscriber
+ * {@link reactor.util.context.Context}.
+ * <p />
+ * {@link org.springframework.transaction.TransactionDefinition#isReadOnly() Readonly} transactions operate on a
+ * {@link ClientSession} and enable causal consistency, and also {@link ClientSession#startTransaction() start},
+ * {@link com.mongodb.reactivestreams.client.ClientSession#commitTransaction() commit} or
+ * {@link ClientSession#abortTransaction() abort} a transaction.
+ * <p />
+ * Application code is required to retrieve the {@link com.mongodb.reactivestreams.client.MongoDatabase} via
+ * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseUtils#getDatabase(ReactiveMongoDatabaseFactory)} instead
+ * of a standard {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory#getMongoDatabase()} call. Spring
+ * classes such as {@link org.springframework.data.mongodb.core.ReactiveMongoTemplate} use this strategy implicitly.
+ * <p />
+ * By default failure of a {@literal commit} operation raises a {@link TransactionSystemException}. You can override
+ * {@link #doCommit(TransactionSynchronizationManager, ReactiveMongoTransactionObject)} to implement the
+ * <a href="https://docs.mongodb.com/manual/core/transactions/#retry-commit-operation">Retry Commit Operation</a>
+ * behavior as outlined in the MongoDB reference manual.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.2
+ * @see <a href="https://www.mongodb.com/transactions">MongoDB Transaction Documentation</a>
+ * @see ReactiveMongoDatabaseUtils#getDatabase(ReactiveMongoDatabaseFactory, SessionSynchronization)
+ */
+public class ReactiveMongoTransactionManager extends AbstractReactiveTransactionManager implements InitializingBean {
+
+	private @Nullable ReactiveMongoDatabaseFactory databaseFactory;
+	private @Nullable TransactionOptions options;
+
+	/**
+	 * Create a new {@link ReactiveMongoTransactionManager} for bean-style usage.
+	 * <p />
+	 * <strong>Note:</strong>The {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory db factory} has to
+	 * be {@link #setDatabaseFactory(ReactiveMongoDatabaseFactory)} set} before using the instance. Use this constructor
+	 * to prepare a {@link ReactiveMongoTransactionManager} via a {@link org.springframework.beans.factory.BeanFactory}.
+	 * <p />
+	 * Optionally it is possible to set default {@link TransactionOptions transaction options} defining
+	 * {@link com.mongodb.ReadConcern} and {@link com.mongodb.WriteConcern}.
+	 *
+	 * @see #setDatabaseFactory(ReactiveMongoDatabaseFactory)
+	 */
+	public ReactiveMongoTransactionManager() {}
+
+	/**
+	 * Create a new {@link ReactiveMongoTransactionManager} obtaining sessions from the given
+	 * {@link ReactiveMongoDatabaseFactory}.
+	 *
+	 * @param databaseFactory must not be {@literal null}.
+	 */
+	public ReactiveMongoTransactionManager(ReactiveMongoDatabaseFactory databaseFactory) {
+		this(databaseFactory, null);
+	}
+
+	/**
+	 * Create a new {@link ReactiveMongoTransactionManager} obtaining sessions from the given
+	 * {@link ReactiveMongoDatabaseFactory} applying the given {@link TransactionOptions options}, if present, when
+	 * starting a new transaction.
+	 *
+	 * @param databaseFactory must not be {@literal null}.
+	 * @param options can be {@literal null}.
+	 */
+	public ReactiveMongoTransactionManager(ReactiveMongoDatabaseFactory databaseFactory,
+			@Nullable TransactionOptions options) {
+
+		Assert.notNull(databaseFactory, "DatabaseFactory must not be null!");
+
+		this.databaseFactory = databaseFactory;
+		this.options = options;
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doGetTransaction(org.springframework.transaction.reactive.TransactionSynchronizationManager)
+	 */
+	@Override
+	protected Object doGetTransaction(TransactionSynchronizationManager synchronizationManager)
+			throws TransactionException {
+
+		ReactiveMongoResourceHolder resourceHolder = (ReactiveMongoResourceHolder) synchronizationManager
+				.getResource(getRequiredDatabaseFactory());
+		return new ReactiveMongoTransactionObject(resourceHolder);
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#isExistingTransaction(java.lang.Object)
+	 */
+	@Override
+	protected boolean isExistingTransaction(Object transaction) throws TransactionException {
+		return extractMongoTransaction(transaction).hasResourceHolder();
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doBegin(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object, org.springframework.transaction.TransactionDefinition)
+	 */
+	@Override
+	protected Mono<Void> doBegin(TransactionSynchronizationManager synchronizationManager, Object transaction,
+			TransactionDefinition definition) throws TransactionException {
+
+		return Mono.defer(() -> {
+
+			ReactiveMongoTransactionObject mongoTransactionObject = extractMongoTransaction(transaction);
+
+			Mono<ReactiveMongoResourceHolder> holder = newResourceHolder(definition,
+					ClientSessionOptions.builder().causallyConsistent(true).build());
+
+			return holder.doOnNext(resourceHolder -> {
+
+				mongoTransactionObject.setResourceHolder(resourceHolder);
+
+				if (logger.isDebugEnabled()) {
+					logger.debug(
+							String.format("About to start transaction for session %s.", debugString(resourceHolder.getSession())));
+				}
+
+			}).doOnNext(resourceHolder -> {
+
+				mongoTransactionObject.startTransaction(options);
+
+				if (logger.isDebugEnabled()) {
+					logger.debug(String.format("Started transaction for session %s.", debugString(resourceHolder.getSession())));
+				}
+
+			})//
+					.onErrorMap(
+							ex -> new TransactionSystemException(String.format("Could not start Mongo transaction for session %s.",
+									debugString(mongoTransactionObject.getSession())), ex))
+					.doOnSuccess(resourceHolder -> {
+
+						synchronizationManager.bindResource(getRequiredDatabaseFactory(), resourceHolder);
+					}).then();
+		});
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doSuspend(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object)
+	 */
+	@Override
+	protected Mono<Object> doSuspend(TransactionSynchronizationManager synchronizationManager, Object transaction)
+			throws TransactionException {
+
+		return Mono.fromSupplier(() -> {
+
+			ReactiveMongoTransactionObject mongoTransactionObject = extractMongoTransaction(transaction);
+			mongoTransactionObject.setResourceHolder(null);
+
+			return synchronizationManager.unbindResource(getRequiredDatabaseFactory());
+		});
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doResume(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object, java.lang.Object)
+	 */
+	@Override
+	protected Mono<Void> doResume(TransactionSynchronizationManager synchronizationManager, @Nullable Object transaction,
+			Object suspendedResources) {
+		return Mono
+				.fromRunnable(() -> synchronizationManager.bindResource(getRequiredDatabaseFactory(), suspendedResources));
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doCommit(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
+	 */
+	@Override
+	protected final Mono<Void> doCommit(TransactionSynchronizationManager synchronizationManager,
+			GenericReactiveTransaction status) throws TransactionException {
+
+		return Mono.defer(() -> {
+
+			ReactiveMongoTransactionObject mongoTransactionObject = extractMongoTransaction(status);
+
+			if (logger.isDebugEnabled()) {
+				logger.debug(String.format("About to commit transaction for session %s.",
+						debugString(mongoTransactionObject.getSession())));
+			}
+
+			return doCommit(synchronizationManager, mongoTransactionObject).onErrorMap(ex -> {
+				return new TransactionSystemException(String.format("Could not commit Mongo transaction for session %s.",
+						debugString(mongoTransactionObject.getSession())), ex);
+			});
+		});
+	}
+
+	/**
+	 * Customization hook to perform an actual commit of the given transaction.<br />
+	 * If a commit operation encounters an error, the MongoDB driver throws a {@link MongoException} holding
+	 * {@literal error labels}. <br />
+	 * By default those labels are ignored, nevertheless one might check for
+	 * {@link MongoException#UNKNOWN_TRANSACTION_COMMIT_RESULT_LABEL transient commit errors labels} and retry the the
+	 * commit.
+	 *
+	 * @param synchronizationManager reactive synchronization manager.
+	 * @param transactionObject never {@literal null}.
+	 */
+	protected Mono<Void> doCommit(TransactionSynchronizationManager synchronizationManager,
+			ReactiveMongoTransactionObject transactionObject) {
+		return transactionObject.commitTransaction();
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doRollback(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
+	 */
+	@Override
+	protected Mono<Void> doRollback(TransactionSynchronizationManager synchronizationManager,
+			GenericReactiveTransaction status) {
+
+		return Mono.defer(() -> {
+
+			ReactiveMongoTransactionObject mongoTransactionObject = extractMongoTransaction(status);
+
+			if (logger.isDebugEnabled()) {
+				logger.debug(String.format("About to abort transaction for session %s.",
+						debugString(mongoTransactionObject.getSession())));
+			}
+
+			return mongoTransactionObject.abortTransaction().onErrorResume(MongoException.class, ex -> {
+				return Mono
+						.error(new TransactionSystemException(String.format("Could not abort Mongo transaction for session %s.",
+								debugString(mongoTransactionObject.getSession())), ex));
+			});
+		});
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doSetRollbackOnly(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
+	 */
+	@Override
+	protected Mono<Void> doSetRollbackOnly(TransactionSynchronizationManager synchronizationManager,
+			GenericReactiveTransaction status) throws TransactionException {
+
+		return Mono.fromRunnable(() -> {
+			ReactiveMongoTransactionObject transactionObject = extractMongoTransaction(status);
+			transactionObject.getRequiredResourceHolder().setRollbackOnly();
+		});
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doCleanupAfterCompletion(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object)
+	 */
+	@Override
+	protected Mono<Void> doCleanupAfterCompletion(TransactionSynchronizationManager synchronizationManager,
+			Object transaction) {
+
+		Assert.isInstanceOf(ReactiveMongoTransactionObject.class, transaction,
+				() -> String.format("Expected to find a %s but it turned out to be %s.", ReactiveMongoTransactionObject.class,
+						transaction.getClass()));
+
+		return Mono.fromRunnable(() -> {
+			ReactiveMongoTransactionObject mongoTransactionObject = (ReactiveMongoTransactionObject) transaction;
+
+			// Remove the connection holder from the thread.
+			synchronizationManager.unbindResource(getRequiredDatabaseFactory());
+			mongoTransactionObject.getRequiredResourceHolder().clear();
+
+			if (logger.isDebugEnabled()) {
+				logger.debug(String.format("About to release Session %s after transaction.",
+						debugString(mongoTransactionObject.getSession())));
+			}
+
+			mongoTransactionObject.closeSession();
+		});
+	}
+
+	/**
+	 * Set the {@link ReactiveMongoDatabaseFactory} that this instance should manage transactions for.
+	 *
+	 * @param databaseFactory must not be {@literal null}.
+	 */
+	public void setDatabaseFactory(ReactiveMongoDatabaseFactory databaseFactory) {
+
+		Assert.notNull(databaseFactory, "DatabaseFactory must not be null!");
+		this.databaseFactory = databaseFactory;
+	}
+
+	/**
+	 * Set the {@link TransactionOptions} to be applied when starting transactions.
+	 *
+	 * @param options can be {@literal null}.
+	 */
+	public void setOptions(@Nullable TransactionOptions options) {
+		this.options = options;
+	}
+
+	/**
+	 * Get the {@link ReactiveMongoDatabaseFactory} that this instance manages transactions for.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public ReactiveMongoDatabaseFactory getDatabaseFactory() {
+		return databaseFactory;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+	 */
+	@Override
+	public void afterPropertiesSet() {
+		getRequiredDatabaseFactory();
+	}
+
+	private Mono<ReactiveMongoResourceHolder> newResourceHolder(TransactionDefinition definition,
+			ClientSessionOptions options) {
+
+		ReactiveMongoDatabaseFactory dbFactory = getRequiredDatabaseFactory();
+
+		return dbFactory.getSession(options).map(session -> new ReactiveMongoResourceHolder(session, dbFactory));
+	}
+
+	/**
+	 * @throws IllegalStateException if {@link #databaseFactory} is {@literal null}.
+	 */
+	private ReactiveMongoDatabaseFactory getRequiredDatabaseFactory() {
+
+		Assert.state(databaseFactory != null,
+				"ReactiveMongoTransactionManager operates upon a ReactiveMongoDatabaseFactory. Did you forget to provide one? It's required.");
+
+		return databaseFactory;
+	}
+
+	private static ReactiveMongoTransactionObject extractMongoTransaction(Object transaction) {
+
+		Assert.isInstanceOf(ReactiveMongoTransactionObject.class, transaction,
+				() -> String.format("Expected to find a %s but it turned out to be %s.", ReactiveMongoTransactionObject.class,
+						transaction.getClass()));
+
+		return (ReactiveMongoTransactionObject) transaction;
+	}
+
+	private static ReactiveMongoTransactionObject extractMongoTransaction(GenericReactiveTransaction status) {
+
+		Assert.isInstanceOf(ReactiveMongoTransactionObject.class, status.getTransaction(),
+				() -> String.format("Expected to find a %s but it turned out to be %s.", ReactiveMongoTransactionObject.class,
+						status.getTransaction().getClass()));
+
+		return (ReactiveMongoTransactionObject) status.getTransaction();
+	}
+
+	private static String debugString(@Nullable ClientSession session) {
+
+		if (session == null) {
+			return "null";
+		}
+
+		String debugString = String.format("[%s@%s ", ClassUtils.getShortName(session.getClass()),
+				Integer.toHexString(session.hashCode()));
+
+		try {
+			if (session.getServerSession() != null) {
+				debugString += String.format("id = %s, ", session.getServerSession().getIdentifier());
+				debugString += String.format("causallyConsistent = %s, ", session.isCausallyConsistent());
+				debugString += String.format("txActive = %s, ", session.hasActiveTransaction());
+				debugString += String.format("txNumber = %d, ", session.getServerSession().getTransactionNumber());
+				debugString += String.format("closed = %d, ", session.getServerSession().isClosed());
+				debugString += String.format("clusterTime = %s", session.getClusterTime());
+			} else {
+				debugString += "id = n/a";
+				debugString += String.format("causallyConsistent = %s, ", session.isCausallyConsistent());
+				debugString += String.format("txActive = %s, ", session.hasActiveTransaction());
+				debugString += String.format("clusterTime = %s", session.getClusterTime());
+			}
+		} catch (RuntimeException e) {
+			debugString += String.format("error = %s", e.getMessage());
+		}
+
+		debugString += "]";
+
+		return debugString;
+	}
+
+	/**
+	 * MongoDB specific transaction object, representing a {@link MongoResourceHolder}. Used as transaction object by
+	 * {@link ReactiveMongoTransactionManager}.
+	 *
+	 * @author Christoph Strobl
+	 * @author Mark Paluch
+	 * @since 2.2
+	 * @see ReactiveMongoResourceHolder
+	 */
+	protected static class ReactiveMongoTransactionObject implements SmartTransactionObject {
+
+		private @Nullable ReactiveMongoResourceHolder resourceHolder;
+
+		ReactiveMongoTransactionObject(@Nullable ReactiveMongoResourceHolder resourceHolder) {
+			this.resourceHolder = resourceHolder;
+		}
+
+		/**
+		 * Set the {@link MongoResourceHolder}.
+		 *
+		 * @param resourceHolder can be {@literal null}.
+		 */
+		void setResourceHolder(@Nullable ReactiveMongoResourceHolder resourceHolder) {
+			this.resourceHolder = resourceHolder;
+		}
+
+		/**
+		 * @return {@literal true} if a {@link MongoResourceHolder} is set.
+		 */
+		final boolean hasResourceHolder() {
+			return resourceHolder != null;
+		}
+
+		/**
+		 * Start a MongoDB transaction optionally given {@link TransactionOptions}.
+		 *
+		 * @param options can be {@literal null}
+		 */
+		void startTransaction(@Nullable TransactionOptions options) {
+
+			ClientSession session = getRequiredSession();
+			if (options != null) {
+				session.startTransaction(options);
+			} else {
+				session.startTransaction();
+			}
+		}
+
+		/**
+		 * Commit the transaction.
+		 */
+		public Mono<Void> commitTransaction() {
+			return Mono.from(getRequiredSession().commitTransaction());
+		}
+
+		/**
+		 * Rollback (abort) the transaction.
+		 */
+		public Mono<Void> abortTransaction() {
+			return Mono.from(getRequiredSession().abortTransaction());
+		}
+
+		/**
+		 * Close a {@link ClientSession} without regard to its transactional state.
+		 */
+		void closeSession() {
+
+			ClientSession session = getRequiredSession();
+			if (session.getServerSession() != null && !session.getServerSession().isClosed()) {
+				session.close();
+			}
+		}
+
+		@Nullable
+		public ClientSession getSession() {
+			return resourceHolder != null ? resourceHolder.getSession() : null;
+		}
+
+		private ReactiveMongoResourceHolder getRequiredResourceHolder() {
+
+			Assert.state(resourceHolder != null, "ReactiveMongoResourceHolder is required but not present. o_O");
+			return resourceHolder;
+		}
+
+		private ClientSession getRequiredSession() {
+
+			ClientSession session = getSession();
+			Assert.state(session != null, "A Session is required but it turned out to be null.");
+			return session;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.SmartTransactionObject#isRollbackOnly()
+		 */
+		@Override
+		public boolean isRollbackOnly() {
+			return this.resourceHolder != null && this.resourceHolder.isRollbackOnly();
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.SmartTransactionObject#flush()
+		 */
+		@Override
+		public void flush() {
+			throw new UnsupportedOperationException("flush() not supported");
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/AbstractMongoClientConfiguration.java

@@ -105,6 +105,7 @@ public abstract class AbstractMongoClientConfiguration extends MongoConfiguratio
 		DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory());
 		MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext());
 		converter.setCustomConversions(customConversions());
+		converter.setCodecRegistryProvider(mongoDbFactory());
 
 		return converter;
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/AbstractMongoConfiguration.java

@@ -42,8 +42,10 @@ import com.mongodb.MongoClient;
  * @author Mark Paluch
  * @see MongoConfigurationSupport
  * @see AbstractMongoClientConfiguration
+ * @deprecated since 2.2 in favor of {@link AbstractMongoClientConfiguration}.
  */
 @Configuration
+@Deprecated
 public abstract class AbstractMongoConfiguration extends MongoConfigurationSupport {
 
 	/**
@@ -111,6 +113,7 @@ public abstract class AbstractMongoConfiguration extends MongoConfigurationSuppo
 		DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory());
 		MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext());
 		converter.setCustomConversions(customConversions());
+		converter.setCodecRegistryProvider(mongoDbFactory());
 
 		return converter;
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/AbstractReactiveMongoConfiguration.java

@@ -83,6 +83,7 @@ public abstract class AbstractReactiveMongoConfiguration extends MongoConfigurat
 
 		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mongoMappingContext());
 		converter.setCustomConversions(customConversions());
+		converter.setCodecRegistryProvider(reactiveMongoDbFactory());
 
 		return converter;
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MappingMongoConverterParser.java

@@ -51,7 +51,6 @@ import org.springframework.core.type.filter.AssignableTypeFilter;
 import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.data.annotation.Persistent;
 import org.springframework.data.config.BeanComponentDefinitionBuilder;
-import org.springframework.data.mapping.context.MappingContextIsNewStrategyFactory;
 import org.springframework.data.mapping.model.CamelCaseAbbreviatingFieldNamingStrategy;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
@@ -102,8 +101,6 @@ public class MappingMongoConverterParser implements BeanDefinitionParser {
 		BeanDefinition conversionsDefinition = getCustomConversions(element, parserContext);
 		String ctxRef = potentiallyCreateMappingContext(element, parserContext, conversionsDefinition, id);
 
-		createIsNewStrategyFactoryBeanDefinition(ctxRef, parserContext, element);
-
 		// Need a reference to a Mongo instance
 		String dbFactoryRef = element.getAttribute("db-factory-ref");
 		if (!StringUtils.hasText(dbFactoryRef)) {
@@ -348,20 +345,6 @@ public class MappingMongoConverterParser implements BeanDefinitionParser {
 		return null;
 	}
 
-	public static String createIsNewStrategyFactoryBeanDefinition(String mappingContextRef, ParserContext context,
-			Element element) {
-
-		BeanDefinitionBuilder mappingContextStrategyFactoryBuilder = BeanDefinitionBuilder
-				.rootBeanDefinition(MappingContextIsNewStrategyFactory.class);
-		mappingContextStrategyFactoryBuilder.addConstructorArgReference(mappingContextRef);
-
-		BeanComponentDefinitionBuilder builder = new BeanComponentDefinitionBuilder(element, context);
-		context.registerBeanComponent(
-				builder.getComponent(mappingContextStrategyFactoryBuilder, IS_NEW_STRATEGY_FACTORY_BEAN_NAME));
-
-		return IS_NEW_STRATEGY_FACTORY_BEAN_NAME;
-	}
-
 	/**
 	 * {@link TypeFilter} that returns {@literal false} in case any of the given delegates matches.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoAuditingBeanDefinitionParser.java

@@ -18,6 +18,7 @@ package org.springframework.data.mongodb.config;
 import static org.springframework.data.config.ParsingUtils.*;
 import static org.springframework.data.mongodb.config.BeanNames.*;
 
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.RootBeanDefinition;
@@ -26,25 +27,33 @@ import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.data.auditing.config.IsNewAwareAuditingHandlerBeanDefinitionParser;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
-import org.springframework.data.mongodb.core.mapping.event.AuditingEventListener;
+import org.springframework.data.mongodb.core.mapping.event.AuditingEntityCallback;
+import org.springframework.data.mongodb.core.mapping.event.ReactiveAuditingEntityCallback;
+import org.springframework.lang.Nullable;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
+
 import org.w3c.dom.Element;
 
 /**
- * {@link BeanDefinitionParser} to register a {@link AuditingEventListener} to transparently set auditing information on
- * an entity.
+ * {@link BeanDefinitionParser} to register a {@link AuditingEntityCallback} to transparently set auditing information
+ * on an entity.
  *
  * @author Oliver Gierke
+ * @author Mark Paluch
  */
 public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
 
+	private static boolean PROJECT_REACTOR_AVAILABLE = ClassUtils.isPresent("reactor.core.publisher.Mono",
+			MongoAuditingRegistrar.class.getClassLoader());
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser#getBeanClass(org.w3c.dom.Element)
 	 */
 	@Override
 	protected Class<?> getBeanClass(Element element) {
-		return AuditingEventListener.class;
+		return AuditingEntityCallback.class;
 	}
 
 	/*
@@ -80,7 +89,24 @@ public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinit
 				mappingContextRef);
 		parser.parse(element, parserContext);
 
-		builder.addConstructorArgValue(getObjectFactoryBeanDefinition(parser.getResolvedBeanName(),
-				parserContext.extractSource(element)));
+		AbstractBeanDefinition isNewAwareAuditingHandler = getObjectFactoryBeanDefinition(parser.getResolvedBeanName(),
+				parserContext.extractSource(element));
+		builder.addConstructorArgValue(isNewAwareAuditingHandler);
+
+		if (PROJECT_REACTOR_AVAILABLE) {
+			registerReactiveAuditingEntityCallback(parserContext.getRegistry(), isNewAwareAuditingHandler,
+					parserContext.extractSource(element));
+		}
+	}
+
+	private void registerReactiveAuditingEntityCallback(BeanDefinitionRegistry registry,
+			AbstractBeanDefinition isNewAwareAuditingHandler, @Nullable Object source) {
+
+		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(ReactiveAuditingEntityCallback.class);
+
+		builder.addConstructorArgValue(isNewAwareAuditingHandler);
+		builder.getRawBeanDefinition().setSource(source);
+
+		registry.registerBeanDefinition(ReactiveAuditingEntityCallback.class.getName(), builder.getBeanDefinition());
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoAuditingRegistrar.java

@@ -32,17 +32,23 @@ import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
-import org.springframework.data.mongodb.core.mapping.event.AuditingEventListener;
+import org.springframework.data.mongodb.core.mapping.event.AuditingEntityCallback;
+import org.springframework.data.mongodb.core.mapping.event.ReactiveAuditingEntityCallback;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * {@link ImportBeanDefinitionRegistrar} to enable {@link EnableMongoAuditing} annotation.
  *
  * @author Thomas Darimont
  * @author Oliver Gierke
+ * @author Mark Paluch
  */
 class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
+	private static boolean PROJECT_REACTOR_AVAILABLE = ClassUtils.isPresent("reactor.core.publisher.Mono",
+			MongoAuditingRegistrar.class.getClassLoader());
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAnnotation()
@@ -104,12 +110,27 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		Assert.notNull(registry, "BeanDefinitionRegistry must not be null!");
 
 		BeanDefinitionBuilder listenerBeanDefinitionBuilder = BeanDefinitionBuilder
-				.rootBeanDefinition(AuditingEventListener.class);
+				.rootBeanDefinition(AuditingEntityCallback.class);
 		listenerBeanDefinitionBuilder
 				.addConstructorArgValue(ParsingUtils.getObjectFactoryBeanDefinition(getAuditingHandlerBeanName(), registry));
 
 		registerInfrastructureBeanWithId(listenerBeanDefinitionBuilder.getBeanDefinition(),
-				AuditingEventListener.class.getName(), registry);
+				AuditingEntityCallback.class.getName(), registry);
+
+		if (PROJECT_REACTOR_AVAILABLE) {
+			registerReactiveAuditingEntityCallback(registry, auditingHandlerDefinition.getSource());
+		}
+	}
+
+	private void registerReactiveAuditingEntityCallback(BeanDefinitionRegistry registry, Object source) {
+
+		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(ReactiveAuditingEntityCallback.class);
+
+		builder.addConstructorArgValue(ParsingUtils.getObjectFactoryBeanDefinition(getAuditingHandlerBeanName(), registry));
+		builder.getRawBeanDefinition().setSource(source);
+
+		registerInfrastructureBeanWithId(builder.getBeanDefinition(), ReactiveAuditingEntityCallback.class.getName(),
+				registry);
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoConfigurationSupport.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.mongodb.config;
 
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -28,17 +27,12 @@ import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.type.filter.AnnotationTypeFilter;
 import org.springframework.data.annotation.Persistent;
 import org.springframework.data.convert.CustomConversions;
-import org.springframework.data.mapping.context.MappingContext;
-import org.springframework.data.mapping.context.MappingContextIsNewStrategyFactory;
-import org.springframework.data.mapping.context.PersistentEntities;
 import org.springframework.data.mapping.model.CamelCaseAbbreviatingFieldNamingStrategy;
 import org.springframework.data.mapping.model.FieldNamingStrategy;
 import org.springframework.data.mapping.model.PropertyNameFieldNamingStrategy;
 import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
 import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
-import org.springframework.data.support.CachingIsNewStrategyFactory;
-import org.springframework.data.support.IsNewStrategyFactory;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
@@ -87,23 +81,11 @@ public abstract class MongoConfigurationSupport {
 		mappingContext.setInitialEntitySet(getInitialEntitySet());
 		mappingContext.setSimpleTypeHolder(customConversions().getSimpleTypeHolder());
 		mappingContext.setFieldNamingStrategy(fieldNamingStrategy());
+		mappingContext.setAutoIndexCreation(autoIndexCreation());
 
 		return mappingContext;
 	}
 
-	/**
-	 * Returns a {@link MappingContextIsNewStrategyFactory} wrapped into a {@link CachingIsNewStrategyFactory}.
-	 *
-	 * @return
-	 * @throws ClassNotFoundException
-	 */
-	@Bean
-	public IsNewStrategyFactory isNewStrategyFactory() throws ClassNotFoundException {
-
-		return new CachingIsNewStrategyFactory(new MappingContextIsNewStrategyFactory(
-				new PersistentEntities(Arrays.<MappingContext<?, ?>> asList(new MappingContext[] { mongoMappingContext() }))));
-	}
-
 	/**
 	 * Register custom {@link Converter}s in a {@link CustomConversions} object if required. These
 	 * {@link CustomConversions} will be registered with the {@link #mappingMongoConverter()} and
@@ -190,4 +172,16 @@ public abstract class MongoConfigurationSupport {
 		return abbreviateFieldNames() ? new CamelCaseAbbreviatingFieldNamingStrategy()
 				: PropertyNameFieldNamingStrategy.INSTANCE;
 	}
+
+	/**
+	 * Configure whether to automatically create indices for domain types by deriving the
+	 * {@link org.springframework.data.mongodb.core.index.IndexDefinition} from the entity or not.
+	 *
+	 * @return {@literal true} by default. <br />
+	 *         <strong>INFO</strong>: As of 3.x the default will be set to {@literal false}.
+	 * @since 2.2
+	 */
+	protected boolean autoIndexCreation() {
+		return true;
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoCredentialPropertyEditor.java

@@ -17,6 +17,7 @@ package org.springframework.data.mongodb.config;
 
 import java.beans.PropertyEditorSupport;
 import java.io.UnsupportedEncodingException;
+import java.lang.reflect.Method;
 import java.net.URLDecoder;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -26,6 +27,7 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 
 import com.mongodb.MongoCredential;
@@ -78,12 +80,23 @@ public class MongoCredentialPropertyEditor extends PropertyEditorSupport {
 
 						verifyUserNamePresent(userNameAndPassword);
 						credentials.add(MongoCredential.createGSSAPICredential(userNameAndPassword[0]));
-					} else if (MongoCredential.MONGODB_CR_MECHANISM.equals(authMechanism)) {
+					} else if ("MONGODB-CR".equals(authMechanism)) {
 
 						verifyUsernameAndPasswordPresent(userNameAndPassword);
 						verifyDatabasePresent(database);
-						credentials.add(MongoCredential.createMongoCRCredential(userNameAndPassword[0], database,
-								userNameAndPassword[1].toCharArray()));
+
+						Method createCRCredentialMethod = ReflectionUtils.findMethod(MongoCredential.class,
+								"createMongoCRCredential", String.class, String.class, char[].class);
+
+						if (createCRCredentialMethod == null) {
+							throw new IllegalArgumentException("MONGODB-CR is no longer supported.");
+						}
+
+						MongoCredential credential = MongoCredential.class
+								.cast(ReflectionUtils.invokeMethod(createCRCredentialMethod, null, userNameAndPassword[0], database,
+										userNameAndPassword[1].toCharArray()));
+						credentials.add(credential);
+
 					} else if (MongoCredential.MONGODB_X509_MECHANISM.equals(authMechanism)) {
 
 						verifyUserNamePresent(userNameAndPassword);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoParsingUtils.java

@@ -35,6 +35,7 @@ import org.w3c.dom.Element;
  * @author Oliver Gierke
  * @author Thomas Darimont
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 @SuppressWarnings("deprecation")
 abstract class MongoParsingUtils {
@@ -92,6 +93,7 @@ abstract class MongoParsingUtils {
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "heartbeat-socket-timeout", "heartbeatSocketTimeout");
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "ssl", "ssl");
 		setPropertyReference(clientOptionsDefBuilder, optionsElement, "ssl-socket-factory-ref", "sslSocketFactory");
+		setPropertyReference(clientOptionsDefBuilder, optionsElement, "encryption-settings-ref", "autoEncryptionSettings");
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "server-selection-timeout", "serverSelectionTimeout");
 
 		mongoClientBuilder.addPropertyValue("mongoClientOptions", clientOptionsDefBuilder.getBeanDefinition());

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/BulkOperations.java

@@ -31,6 +31,7 @@ import com.mongodb.bulk.BulkWriteResult;
  *
  * @author Tobias Trelle
  * @author Oliver Gierke
+ * @author Minsu Kim
  * @since 1.9
  */
 public interface BulkOperations {
@@ -135,6 +136,29 @@ public interface BulkOperations {
 	 */
 	BulkOperations remove(List<Query> removes);
 
+	/**
+	 * Add a single replace operation to the bulk operation.
+	 *
+	 * @param query Update criteria.
+	 * @param replacement the replacement document. Must not be {@literal null}.
+	 * @return the current {@link BulkOperations} instance with the replace added, will never be {@literal null}.
+	 * @since 2.2
+	 */
+	default BulkOperations replaceOne(Query query, Object replacement) {
+		return replaceOne(query, replacement, FindAndReplaceOptions.empty());
+	}
+
+	/**
+	 * Add a single replace operation to the bulk operation.
+	 *
+	 * @param query Update criteria.
+	 * @param replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @return the current {@link BulkOperations} instance with the replace added, will never be {@literal null}.
+	 * @since 2.2
+	 */
+	BulkOperations replaceOne(Query query, Object replacement, FindAndReplaceOptions options);
+
 	/**
 	 * Execute all bulk operations using the default write concern.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ChangeStreamEvent.java

@@ -20,6 +20,7 @@ import lombok.EqualsAndHashCode;
 import java.time.Instant;
 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
 
+import org.bson.BsonTimestamp;
 import org.bson.BsonValue;
 import org.bson.Document;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
@@ -84,8 +85,19 @@ public class ChangeStreamEvent<T> {
 	@Nullable
 	public Instant getTimestamp() {
 
-		return raw != null && raw.getClusterTime() != null
-				? converter.getConversionService().convert(raw.getClusterTime(), Instant.class) : null;
+		return getBsonTimestamp() != null ? converter.getConversionService().convert(raw.getClusterTime(), Instant.class)
+				: null;
+	}
+
+	/**
+	 * Get the {@link ChangeStreamDocument#getClusterTime() cluster time}.
+	 *
+	 * @return can be {@literal null}.
+	 * @since 2.2
+	 */
+	@Nullable
+	public BsonTimestamp getBsonTimestamp() {
+		return raw != null ? raw.getClusterTime() : null;
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ChangeStreamOptions.java

@@ -21,12 +21,17 @@ import java.time.Instant;
 import java.util.Arrays;
 import java.util.Optional;
 
+import org.bson.BsonDocument;
+import org.bson.BsonTimestamp;
 import org.bson.BsonValue;
 import org.bson.Document;
+
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ObjectUtils;
 
 import com.mongodb.client.model.changestream.ChangeStreamDocument;
 import com.mongodb.client.model.changestream.FullDocument;
@@ -47,7 +52,8 @@ public class ChangeStreamOptions {
 	private @Nullable BsonValue resumeToken;
 	private @Nullable FullDocument fullDocumentLookup;
 	private @Nullable Collation collation;
-	private @Nullable Instant resumeTimestamp;
+	private @Nullable Object resumeTimestamp;
+	private Resume resume = Resume.UNDEFINED;
 
 	protected ChangeStreamOptions() {}
 
@@ -83,7 +89,31 @@ public class ChangeStreamOptions {
 	 * @return {@link Optional#empty()} if not set.
 	 */
 	public Optional<Instant> getResumeTimestamp() {
-		return Optional.ofNullable(resumeTimestamp);
+		return Optional.ofNullable(resumeTimestamp).map(timestamp -> asTimestampOfType(timestamp, Instant.class));
+	}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 * @since 2.2
+	 */
+	public Optional<BsonTimestamp> getResumeBsonTimestamp() {
+		return Optional.ofNullable(resumeTimestamp).map(timestamp -> asTimestampOfType(timestamp, BsonTimestamp.class));
+	}
+
+	/**
+	 * @return {@literal true} if the change stream should be started after the {@link #getResumeToken() token}.
+	 * @since 2.2
+	 */
+	public boolean isStartAfter() {
+		return Resume.START_AFTER.equals(resume);
+	}
+
+	/**
+	 * @return {@literal true} if the change stream should be resumed after the {@link #getResumeToken() token}.
+	 * @since 2.2
+	 */
+	public boolean isResumeAfter() {
+		return Resume.RESUME_AFTER.equals(resume);
 	}
 
 	/**
@@ -103,6 +133,48 @@ public class ChangeStreamOptions {
 		return new ChangeStreamOptionsBuilder();
 	}
 
+	private static <T> T asTimestampOfType(Object timestamp, Class<T> targetType) {
+		return targetType.cast(doGetTimestamp(timestamp, targetType));
+	}
+
+	private static <T> Object doGetTimestamp(Object timestamp, Class<T> targetType) {
+
+		if (ClassUtils.isAssignableValue(targetType, timestamp)) {
+			return timestamp;
+		}
+
+		if (timestamp instanceof Instant) {
+			return new BsonTimestamp((int) ((Instant) timestamp).getEpochSecond(), 0);
+		}
+
+		if (timestamp instanceof BsonTimestamp) {
+			return Instant.ofEpochSecond(((BsonTimestamp) timestamp).getTime());
+		}
+
+		throw new IllegalArgumentException(
+				"o_O that should actually not happen. The timestamp should be an Instant or a BsonTimestamp but was "
+						+ ObjectUtils.nullSafeClassName(timestamp));
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.2
+	 */
+	enum Resume {
+
+		UNDEFINED,
+
+		/**
+		 * @see com.mongodb.client.ChangeStreamIterable#startAfter(BsonDocument)
+		 */
+		START_AFTER,
+
+		/**
+		 * @see com.mongodb.client.ChangeStreamIterable#resumeAfter(BsonDocument)
+		 */
+		RESUME_AFTER
+	}
+
 	/**
 	 * Builder for creating {@link ChangeStreamOptions}.
 	 *
@@ -115,7 +187,8 @@ public class ChangeStreamOptions {
 		private @Nullable BsonValue resumeToken;
 		private @Nullable FullDocument fullDocumentLookup;
 		private @Nullable Collation collation;
-		private @Nullable Instant resumeTimestamp;
+		private @Nullable Object resumeTimestamp;
+		private Resume resume = Resume.UNDEFINED;
 
 		private ChangeStreamOptionsBuilder() {}
 
@@ -183,6 +256,11 @@ public class ChangeStreamOptions {
 			Assert.notNull(resumeToken, "ResumeToken must not be null!");
 
 			this.resumeToken = resumeToken;
+
+			if (this.resume == Resume.UNDEFINED) {
+				this.resume = Resume.RESUME_AFTER;
+			}
+
 			return this;
 		}
 
@@ -224,6 +302,51 @@ public class ChangeStreamOptions {
 			return this;
 		}
 
+		/**
+		 * Set the cluster time to resume from.
+		 *
+		 * @param resumeTimestamp must not be {@literal null}.
+		 * @return this.
+		 * @since 2.2
+		 */
+		public ChangeStreamOptionsBuilder resumeAt(BsonTimestamp resumeTimestamp) {
+
+			Assert.notNull(resumeTimestamp, "ResumeTimestamp must not be null!");
+
+			this.resumeTimestamp = resumeTimestamp;
+			return this;
+		}
+
+		/**
+		 * Set the resume token after which to continue emitting notifications.
+		 *
+		 * @param resumeToken must not be {@literal null}.
+		 * @return this.
+		 * @since 2.2
+		 */
+		public ChangeStreamOptionsBuilder resumeAfter(BsonValue resumeToken) {
+
+			resumeToken(resumeToken);
+			this.resume = Resume.RESUME_AFTER;
+
+			return this;
+		}
+
+		/**
+		 * Set the resume token after which to start emitting notifications.
+		 *
+		 * @param resumeToken must not be {@literal null}.
+		 * @return this.
+		 * @since 2.2
+		 */
+		public ChangeStreamOptionsBuilder startAfter(BsonValue resumeToken) {
+
+			resumeToken(resumeToken);
+			this.resume = Resume.START_AFTER;
+
+			return this;
+		}
+
 		/**
 		 * @return the built {@link ChangeStreamOptions}
 		 */
@@ -231,11 +354,12 @@ public class ChangeStreamOptions {
 
 			ChangeStreamOptions options = new ChangeStreamOptions();
 
-			options.filter = filter;
-			options.resumeToken = resumeToken;
-			options.fullDocumentLookup = fullDocumentLookup;
-			options.collation = collation;
-			options.resumeTimestamp = resumeTimestamp;
+			options.filter = this.filter;
+			options.resumeToken = this.resumeToken;
+			options.fullDocumentLookup = this.fullDocumentLookup;
+			options.collation = this.collation;
+			options.resumeTimestamp = this.resumeTimestamp;
+			options.resume = this.resume;
 
 			return options;
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/CountQuery.java

@@ -0,0 +1,227 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+import org.bson.Document;
+
+import org.springframework.data.geo.Point;
+import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * Value object representing a count query. Count queries using {@code $near} or {@code $nearSphere} require a rewrite
+ * to {@code $geoWithin}.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 3.0
+ */
+class CountQuery {
+
+	private Document source;
+
+	private CountQuery(Document source) {
+		this.source = source;
+	}
+
+	public static CountQuery of(Document source) {
+		return new CountQuery(source);
+	}
+
+	/**
+	 * Returns the query {@link Document} that can be used with {@code countDocuments()}. Potentially rewrites the query
+	 * to be usable with {@code countDocuments()}.
+	 *
+	 * @return the query {@link Document} that can be used with {@code countDocuments()}.
+	 */
+	public Document toQueryDocument() {
+
+		if (!requiresRewrite(source)) {
+			return source;
+		}
+
+		Document target = new Document();
+
+		for (Map.Entry<String, Object> entry : source.entrySet()) {
+
+			if (entry.getValue() instanceof Document && requiresRewrite(entry.getValue())) {
+
+				Document theValue = (Document) entry.getValue();
+				target.putAll(createGeoWithin(entry.getKey(), theValue, source.get("$and")));
+				continue;
+			}
+
+			if (entry.getValue() instanceof Collection && requiresRewrite(entry.getValue())) {
+
+				Collection<?> source = (Collection<?>) entry.getValue();
+
+				target.put(entry.getKey(), rewriteCollection(source));
+				continue;
+			}
+
+			if ("$and".equals(entry.getKey()) && target.containsKey("$and")) {
+				// Expect $and to be processed with Document and createGeoWithin.
+				continue;
+			}
+
+			target.put(entry.getKey(), entry.getValue());
+		}
+
+		return target;
+	}
+
+	/**
+	 * @param valueToInspect
+	 * @return {@code true} if the enclosing element needs to be rewritten.
+	 */
+	private boolean requiresRewrite(Object valueToInspect) {
+
+		if (valueToInspect instanceof Document) {
+			return requiresRewrite((Document) valueToInspect);
+		}
+
+		if (valueToInspect instanceof Collection) {
+			return requiresRewrite((Collection) valueToInspect);
+		}
+
+		return false;
+	}
+
+	private boolean requiresRewrite(Collection<?> collection) {
+
+		for (Object o : collection) {
+			if (o instanceof Document && requiresRewrite((Document) o)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	private boolean requiresRewrite(Document document) {
+
+		if (containsNear(document)) {
+			return true;
+		}
+
+		for (Object entry : document.values()) {
+
+			if (requiresRewrite(entry)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	private Collection<Object> rewriteCollection(Collection<?> source) {
+
+		Collection<Object> rewrittenCollection = new ArrayList<>(source.size());
+
+		for (Object item : source) {
+			if (item instanceof Document && requiresRewrite(item)) {
+				rewrittenCollection.add(CountQuery.of((Document) item).toQueryDocument());
+			} else {
+				rewrittenCollection.add(item);
+			}
+		}
+
+		return rewrittenCollection;
+	}
+
+	/**
+	 * Rewrite the near query for field {@code key} to {@code $geoWithin}.
+	 *
+	 * @param key the queried field.
+	 * @param source source {@link Document}.
+	 * @param $and potentially existing {@code $and} condition.
+	 * @return the rewritten query {@link Document}.
+	 */
+	private static Document createGeoWithin(String key, Document source, @Nullable Object $and) {
+
+		boolean spheric = source.containsKey("$nearSphere");
+		Object $near = spheric ? source.get("$nearSphere") : source.get("$near");
+
+		Number maxDistance = source.containsKey("$maxDistance") ? (Number) source.get("$maxDistance") : Double.MAX_VALUE;
+		List<Object> $centerMax = Arrays.asList(toCenterCoordinates($near), maxDistance);
+		Document $geoWithinMax = new Document("$geoWithin",
+				new Document(spheric ? "$centerSphere" : "$center", $centerMax));
+
+		if (!containsNearWithMinDistance(source)) {
+			return new Document(key, $geoWithinMax);
+		}
+
+		Number minDistance = (Number) source.get("$minDistance");
+		List<Object> $centerMin = Arrays.asList(toCenterCoordinates($near), minDistance);
+		Document $geoWithinMin = new Document("$geoWithin",
+				new Document(spheric ? "$centerSphere" : "$center", $centerMin));
+
+		List<Document> criteria = new ArrayList<>();
+
+		if ($and != null) {
+			if ($and instanceof Collection) {
+				criteria.addAll((Collection) $and);
+			} else {
+				throw new IllegalArgumentException(
+						"Cannot rewrite query as it contains an '$and' element that is not a Collection!: Offending element: "
+								+ $and);
+			}
+		}
+
+		criteria.add(new Document("$nor", Collections.singletonList(new Document(key, $geoWithinMin))));
+		criteria.add(new Document(key, $geoWithinMax));
+		return new Document("$and", criteria);
+	}
+
+	private static boolean containsNear(Document source) {
+		return source.containsKey("$near") || source.containsKey("$nearSphere");
+	}
+
+	private static boolean containsNearWithMinDistance(Document source) {
+
+		if (!containsNear(source)) {
+			return false;
+		}
+
+		return source.containsKey("$minDistance");
+	}
+
+	private static Object toCenterCoordinates(Object value) {
+
+		if (ObjectUtils.isArray(value)) {
+			return value;
+		}
+
+		if (value instanceof Point) {
+			return Arrays.asList(((Point) value).getX(), ((Point) value).getY());
+		}
+
+		if (value instanceof Document && ((Document) value).containsKey("x")) {
+
+			Document point = (Document) value;
+			return Arrays.asList(point.get("x"), point.get("y"));
+		}
+
+		return value;
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/CursorPreparer.java

@@ -15,9 +15,15 @@
  */
 package org.springframework.data.mongodb.core;
 
-import org.bson.Document;
+import java.util.function.Function;
 
+import org.bson.Document;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+import com.mongodb.ReadPreference;
 import com.mongodb.client.FindIterable;
+import com.mongodb.client.MongoCollection;
 
 /**
  * Simple callback interface to allow customization of a {@link FindIterable}.
@@ -25,7 +31,14 @@ import com.mongodb.client.FindIterable;
  * @author Oliver Gierke
  * @author Christoph Strobl
  */
-public interface CursorPreparer {
+public interface CursorPreparer extends ReadPreferenceAware {
+
+	/**
+	 * Default {@link CursorPreparer} just passing on the given {@link FindIterable}.
+	 *
+	 * @since 2.2
+	 */
+	CursorPreparer NO_OP_PREPARER = (iterable -> iterable);
 
 	/**
 	 * Prepare the given cursor (apply limits, skips and so on). Returns the prepared cursor.
@@ -33,4 +46,37 @@ public interface CursorPreparer {
 	 * @param cursor
 	 */
 	FindIterable<Document> prepare(FindIterable<Document> cursor);
+
+	/**
+	 * Apply query specific settings to {@link MongoCollection} and initate a find operation returning a
+	 * {@link FindIterable} via the given {@link Function find} function.
+	 *
+	 * @param collection must not be {@literal null}.
+	 * @param find must not be {@literal null}.
+	 * @return
+	 * @throws IllegalArgumentException if one of the required arguments is {@literal null}.
+	 * @since 2.2
+	 */
+	default FindIterable<Document> initiateFind(MongoCollection<Document> collection,
+			Function<MongoCollection<Document>, FindIterable<Document>> find) {
+
+		Assert.notNull(collection, "Collection must not be null!");
+		Assert.notNull(find, "Find function must not be null!");
+
+		if (hasReadPreference()) {
+			collection = collection.withReadPreference(getReadPreference());
+		}
+
+		return prepare(find.apply(collection));
+	}
+
+	/**
+	 * @return the {@link ReadPreference} to apply or {@literal null} if none defined.
+	 * @since 2.2
+	 */
+	@Override
+	@Nullable
+	default ReadPreference getReadPreference() {
+		return null;
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/DefaultBulkOperations.java

@@ -26,30 +26,31 @@ import java.util.stream.Collectors;
 
 import org.bson.Document;
 import org.bson.conversions.Bson;
-import org.springframework.dao.DataAccessException;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
+import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.mongodb.core.convert.QueryMapper;
 import org.springframework.data.mongodb.core.convert.UpdateMapper;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.event.AfterSaveEvent;
+import org.springframework.data.mongodb.core.mapping.event.BeforeConvertCallback;
+import org.springframework.data.mongodb.core.mapping.event.BeforeConvertEvent;
+import org.springframework.data.mongodb.core.mapping.event.BeforeSaveCallback;
+import org.springframework.data.mongodb.core.mapping.event.BeforeSaveEvent;
+import org.springframework.data.mongodb.core.mapping.event.MongoMappingEvent;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
+import org.springframework.data.mongodb.core.query.UpdateDefinition.ArrayFilter;
 import org.springframework.data.util.Pair;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
-import com.mongodb.BulkWriteException;
 import com.mongodb.WriteConcern;
+import com.mongodb.bulk.BulkWriteResult;
 import com.mongodb.client.MongoCollection;
-import com.mongodb.client.model.BulkWriteOptions;
-import com.mongodb.client.model.DeleteManyModel;
-import com.mongodb.client.model.DeleteOneModel;
-import com.mongodb.client.model.DeleteOptions;
-import com.mongodb.client.model.InsertOneModel;
-import com.mongodb.client.model.UpdateManyModel;
-import com.mongodb.client.model.UpdateOneModel;
-import com.mongodb.client.model.UpdateOptions;
-import com.mongodb.client.model.WriteModel;
+import com.mongodb.client.model.*;
 
 /**
  * Default implementation for {@link BulkOperations}.
@@ -58,6 +59,8 @@ import com.mongodb.client.model.WriteModel;
  * @author Oliver Gierke
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Minsu Kim
+ * @author Jens Schauder
  * @author Michail Nikolaev
  * @since 1.9
  */
@@ -66,7 +69,7 @@ class DefaultBulkOperations implements BulkOperations {
 	private final MongoOperations mongoOperations;
 	private final String collectionName;
 	private final BulkOperationContext bulkOperationContext;
-	private final List<WriteModel<Document>> models = new ArrayList<>();
+	private final List<SourceAwareWriteModelHolder> models = new ArrayList<>();
 
 	private PersistenceExceptionTranslator exceptionTranslator;
 	private @Nullable WriteConcern defaultWriteConcern;
@@ -123,16 +126,9 @@ class DefaultBulkOperations implements BulkOperations {
 
 		Assert.notNull(document, "Document must not be null!");
 
-		if (document instanceof Document) {
-
-			models.add(new InsertOneModel<>((Document) document));
-			return this;
-		}
-
-		Document sink = new Document();
-		mongoOperations.getConverter().write(document, sink);
-
-		models.add(new InsertOneModel<>(sink));
+		maybeEmitEvent(new BeforeConvertEvent<>(document, collectionName));
+		Object source = maybeInvokeBeforeConvertCallback(document);
+		addModel(source, new InsertOneModel<>(getMappedObject(source)));
 
 		return this;
 	}
@@ -246,7 +242,7 @@ class DefaultBulkOperations implements BulkOperations {
 		DeleteOptions deleteOptions = new DeleteOptions();
 		query.getCollation().map(Collation::toMongoCollation).ifPresent(deleteOptions::collation);
 
-		models.add(new DeleteManyModel<>(query.getQueryObject(), deleteOptions));
+		addModel(query, new DeleteManyModel<>(query.getQueryObject(), deleteOptions));
 
 		return this;
 	}
@@ -267,6 +263,29 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.BulkOperations#replaceOne(org.springframework.data.mongodb.core.query.Query, java.lang.Object, org.springframework.data.mongodb.core.FindAndReplaceOptions)
+	 */
+	@Override
+	public BulkOperations replaceOne(Query query, Object replacement, FindAndReplaceOptions options) {
+
+		Assert.notNull(query, "Query must not be null!");
+		Assert.notNull(replacement, "Replacement must not be null!");
+		Assert.notNull(options, "Options must not be null!");
+
+		ReplaceOptions replaceOptions = new ReplaceOptions();
+		replaceOptions.upsert(options.isUpsert());
+		query.getCollation().map(Collation::toMongoCollation).ifPresent(replaceOptions::collation);
+
+		maybeEmitEvent(new BeforeConvertEvent<>(replacement, collectionName));
+		Object source = maybeInvokeBeforeConvertCallback(replacement);
+		addModel(source,
+				new ReplaceOneModel<>(getMappedQuery(query.getQueryObject()), getMappedObject(source), replaceOptions));
+
+		return this;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.BulkOperations#executeBulk()
@@ -276,18 +295,48 @@ class DefaultBulkOperations implements BulkOperations {
 
 		try {
 
-			return mongoOperations.execute(collectionName, collection -> {
+			com.mongodb.bulk.BulkWriteResult result = mongoOperations.execute(collectionName, this::bulkWriteTo);
 
-				if (defaultWriteConcern != null) {
-					collection = collection.withWriteConcern(defaultWriteConcern);
-				}
-				return collection.bulkWrite(models.stream().map(this::mapWriteModel).collect(Collectors.toList()), bulkOptions);
-			});
+			Assert.state(result != null, "Result must not be null.");
+
+			models.forEach(this::maybeEmitAfterSaveEvent);
+
+			return result;
 		} finally {
 			this.bulkOptions = getBulkWriteOptions(bulkOperationContext.getBulkMode());
 		}
 	}
 
+	private BulkWriteResult bulkWriteTo(MongoCollection<Document> collection) {
+
+		if (defaultWriteConcern != null) {
+			collection = collection.withWriteConcern(defaultWriteConcern);
+		}
+
+		return collection.bulkWrite( //
+				models.stream() //
+						.map(this::extractAndMapWriteModel) //
+						.collect(Collectors.toList()), //
+				bulkOptions);
+	}
+
+	private WriteModel<Document> extractAndMapWriteModel(SourceAwareWriteModelHolder it) {
+
+		maybeEmitBeforeSaveEvent(it);
+
+		if (it.getModel() instanceof InsertOneModel) {
+
+			Document target = ((InsertOneModel<Document>) it.getModel()).getDocument();
+			maybeInvokeBeforeSaveCallback(it.getSource(), target);
+		} else if (it.getModel() instanceof ReplaceOneModel) {
+
+			Document target = ((ReplaceOneModel<Document>) it.getModel()).getReplacement();
+			maybeInvokeBeforeSaveCallback(it.getSource(), target);
+		}
+
+		return mapWriteModel(it.getModel());
+	}
+
 	/**
 	 * Performs update and upsert bulk operations.
 	 *
@@ -302,14 +351,12 @@ class DefaultBulkOperations implements BulkOperations {
 		Assert.notNull(query, "Query must not be null!");
 		Assert.notNull(update, "Update must not be null!");
 
-		UpdateOptions options = new UpdateOptions();
-		options.upsert(upsert);
-		query.getCollation().map(Collation::toMongoCollation).ifPresent(options::collation);
+		UpdateOptions options = computeUpdateOptions(query, update, upsert);
 
 		if (multi) {
-			models.add(new UpdateManyModel<>(query.getQueryObject(), update.getUpdateObject(), options));
+			addModel(update, new UpdateManyModel<>(query.getQueryObject(), update.getUpdateObject(), options));
 		} else {
-			models.add(new UpdateOneModel<>(query.getQueryObject(), update.getUpdateObject(), options));
+			addModel(update, new UpdateOneModel<>(query.getQueryObject(), update.getUpdateObject(), options));
 		}
 
 		return this;
@@ -358,6 +405,76 @@ class DefaultBulkOperations implements BulkOperations {
 		return bulkOperationContext.getQueryMapper().getMappedObject(query, bulkOperationContext.getEntity());
 	}
 
+	private Document getMappedObject(Object source) {
+
+		if (source instanceof Document) {
+			return (Document) source;
+		}
+
+		Document sink = new Document();
+
+		mongoOperations.getConverter().write(source, sink);
+		return sink;
+	}
+
+	private void addModel(Object source, WriteModel<Document> model) {
+		models.add(new SourceAwareWriteModelHolder(source, model));
+	}
+
+	private void maybeEmitBeforeSaveEvent(SourceAwareWriteModelHolder it) {
+
+		if (it.getModel() instanceof InsertOneModel) {
+
+			Document target = ((InsertOneModel<Document>) it.getModel()).getDocument();
+			maybeEmitEvent(new BeforeSaveEvent<>(it.getSource(), target, collectionName));
+		} else if (it.getModel() instanceof ReplaceOneModel) {
+
+			Document target = ((ReplaceOneModel<Document>) it.getModel()).getReplacement();
+			maybeEmitEvent(new BeforeSaveEvent<>(it.getSource(), target, collectionName));
+		}
+	}
+
+	private void maybeEmitAfterSaveEvent(SourceAwareWriteModelHolder it) {
+
+		if (it.getModel() instanceof InsertOneModel) {
+
+			Document target = ((InsertOneModel<Document>) it.getModel()).getDocument();
+			maybeEmitEvent(new AfterSaveEvent<>(it.getSource(), target, collectionName));
+		} else if (it.getModel() instanceof ReplaceOneModel) {
+
+			Document target = ((ReplaceOneModel<Document>) it.getModel()).getReplacement();
+			maybeEmitEvent(new AfterSaveEvent<>(it.getSource(), target, collectionName));
+		}
+	}
+
+	private <E extends MongoMappingEvent<T>, T> E maybeEmitEvent(E event) {
+
+		if (null != bulkOperationContext.getEventPublisher()) {
+			bulkOperationContext.getEventPublisher().publishEvent(event);
+		}
+
+		return event;
+	}
+
+	private Object maybeInvokeBeforeConvertCallback(Object value) {
+
+		if (bulkOperationContext.getEntityCallbacks() == null) {
+			return value;
+		}
+
+		return bulkOperationContext.getEntityCallbacks().callback(BeforeConvertCallback.class, value, collectionName);
+	}
+
+	private Object maybeInvokeBeforeSaveCallback(Object value, Document mappedDocument) {
+
+		if (bulkOperationContext.getEntityCallbacks() == null) {
+			return value;
+		}
+
+		return bulkOperationContext.getEntityCallbacks().callback(BeforeSaveCallback.class, value, mappedDocument,
+				collectionName);
+	}
+
 	private static BulkWriteOptions getBulkWriteOptions(BulkMode bulkMode) {
 
 		BulkWriteOptions options = new BulkWriteOptions();
@@ -372,6 +489,29 @@ class DefaultBulkOperations implements BulkOperations {
 		throw new IllegalStateException("BulkMode was null!");
 	}
 
+	/**
+	 * @param filterQuery The {@link Query} to read a potential {@link Collation} from. Must not be {@literal null}.
+	 * @param update The {@link Update} to apply
+	 * @param upsert flag to indicate if document should be upserted.
+	 * @return new instance of {@link UpdateOptions}.
+	 */
+	private static UpdateOptions computeUpdateOptions(Query filterQuery, UpdateDefinition update, boolean upsert) {
+
+		UpdateOptions options = new UpdateOptions();
+		options.upsert(upsert);
+
+		if (update.hasArrayFilters()) {
+			List<Document> list = new ArrayList<>(update.getArrayFilters().size());
+			for (ArrayFilter arrayFilter : update.getArrayFilters()) {
+				list.add(arrayFilter.asDocument());
+			}
+			options.arrayFilters(list);
+		}
+
+		filterQuery.getCollation().map(Collation::toMongoCollation).ifPresent(options::collation);
+		return options;
+	}
+
 	/**
 	 * {@link BulkOperationContext} holds information about
 	 * {@link org.springframework.data.mongodb.core.BulkOperations.BulkMode} the entity in use as well as references to
@@ -387,5 +527,20 @@ class DefaultBulkOperations implements BulkOperations {
 		@NonNull Optional<? extends MongoPersistentEntity<?>> entity;
 		@NonNull QueryMapper queryMapper;
 		@NonNull UpdateMapper updateMapper;
+		ApplicationEventPublisher eventPublisher;
+		EntityCallbacks entityCallbacks;
+	}
+
+	/**
+	 * Value object chaining together an actual source with its {@link WriteModel} representation.
+	 *
+	 * @since 2.2
+	 * @author Christoph Strobl
+	 */
+	@Value
+	private static class SourceAwareWriteModelHolder {
+
+		Object source;
+		WriteModel<Document> model;
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/DefaultIndexOperations.java

@@ -120,19 +120,15 @@ public class DefaultIndexOperations implements IndexOperations {
 
 		return execute(collection -> {
 
-			Document indexOptions = indexDefinition.getIndexOptions();
+			MongoPersistentEntity<?> entity = lookupPersistentEntity(type, collectionName);
 
-			IndexOptions ops = IndexConverters.indexDefinitionToIndexOptionsConverter().convert(indexDefinition);
+			IndexOptions indexOptions = IndexConverters.indexDefinitionToIndexOptionsConverter().convert(indexDefinition);
 
-			if (indexOptions.containsKey(PARTIAL_FILTER_EXPRESSION_KEY)) {
+			indexOptions = addPartialFilterIfPresent(indexOptions, indexDefinition.getIndexOptions(), entity);
+			indexOptions = addDefaultCollationIfRequired(indexOptions, entity);
 
-				Assert.isInstanceOf(Document.class, indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY));
-
-				ops.partialFilterExpression(mapper.getMappedObject((Document) indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY),
-						lookupPersistentEntity(type, collectionName)));
-			}
-
-			return collection.createIndex(indexDefinition.getIndexKeys(), ops);
+			Document mappedKeys = mapper.getMappedSort(indexDefinition.getIndexKeys(), entity);
+			return collection.createIndex(mappedKeys, indexOptions);
 		});
 	}
 
@@ -192,7 +188,7 @@ public class DefaultIndexOperations implements IndexOperations {
 
 			private List<IndexInfo> getIndexData(MongoCursor<Document> cursor) {
 
-				List<IndexInfo> indexInfoList = new ArrayList<IndexInfo>();
+				List<IndexInfo> indexInfoList = new ArrayList<>();
 
 				while (cursor.hasNext()) {
 
@@ -217,4 +213,25 @@ public class DefaultIndexOperations implements IndexOperations {
 
 		return mongoOperations.execute(collectionName, callback);
 	}
+
+	private IndexOptions addPartialFilterIfPresent(IndexOptions ops, Document sourceOptions,
+			@Nullable MongoPersistentEntity<?> entity) {
+
+		if (!sourceOptions.containsKey(PARTIAL_FILTER_EXPRESSION_KEY)) {
+			return ops;
+		}
+
+		Assert.isInstanceOf(Document.class, sourceOptions.get(PARTIAL_FILTER_EXPRESSION_KEY));
+		return ops.partialFilterExpression(
+				mapper.getMappedSort((Document) sourceOptions.get(PARTIAL_FILTER_EXPRESSION_KEY), entity));
+	}
+
+	private static IndexOptions addDefaultCollationIfRequired(IndexOptions ops, MongoPersistentEntity<?> entity) {
+
+		if (ops.getCollation() != null || entity == null || !entity.hasCollation()) {
+			return ops;
+		}
+
+		return ops.collation(entity.getCollation().toMongoCollation());
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/DefaultReactiveIndexOperations.java

@@ -94,23 +94,16 @@ public class DefaultReactiveIndexOperations implements ReactiveIndexOperations {
 
 		return mongoOperations.execute(collectionName, collection -> {
 
-			Document indexOptions = indexDefinition.getIndexOptions();
+			MongoPersistentEntity<?> entity = type
+					.map(val -> (MongoPersistentEntity) queryMapper.getMappingContext().getRequiredPersistentEntity(val))
+					.orElseGet(() -> lookupPersistentEntity(collectionName));
 
-			IndexOptions ops = IndexConverters.indexDefinitionToIndexOptionsConverter().convert(indexDefinition);
+			IndexOptions indexOptions = IndexConverters.indexDefinitionToIndexOptionsConverter().convert(indexDefinition);
 
-			if (indexOptions.containsKey(PARTIAL_FILTER_EXPRESSION_KEY)) {
+			indexOptions = addPartialFilterIfPresent(indexOptions, indexDefinition.getIndexOptions(), entity);
+			indexOptions = addDefaultCollationIfRequired(indexOptions, entity);
 
-				Assert.isInstanceOf(Document.class, indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY));
-
-				MongoPersistentEntity<?> entity = type
-						.map(val -> (MongoPersistentEntity) queryMapper.getMappingContext().getRequiredPersistentEntity(val))
-						.orElseGet(() -> lookupPersistentEntity(collectionName));
-
-				ops = ops.partialFilterExpression(
-						queryMapper.getMappedObject(indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY, Document.class), entity));
-			}
-
-			return collection.createIndex(indexDefinition.getIndexKeys(), ops);
+			return collection.createIndex(indexDefinition.getIndexKeys(), indexOptions);
 
 		}).next();
 	}
@@ -126,21 +119,24 @@ public class DefaultReactiveIndexOperations implements ReactiveIndexOperations {
 				.orElse(null);
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#dropIndex(java.lang.String)
 	 */
 	public Mono<Void> dropIndex(final String name) {
 		return mongoOperations.execute(collectionName, collection -> collection.dropIndex(name)).then();
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#dropAllIndexes()
 	 */
 	public Mono<Void> dropAllIndexes() {
 		return dropIndex("*");
 	}
 
-	/* (non-Javadoc)
+	/*
+	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#getIndexInfo()
 	 */
 	public Flux<IndexInfo> getIndexInfo() {
@@ -148,4 +144,25 @@ public class DefaultReactiveIndexOperations implements ReactiveIndexOperations {
 		return mongoOperations.execute(collectionName, collection -> collection.listIndexes(Document.class)) //
 				.map(IndexConverters.documentToIndexInfoConverter()::convert);
 	}
+
+	private IndexOptions addPartialFilterIfPresent(IndexOptions ops, Document sourceOptions,
+			@Nullable MongoPersistentEntity<?> entity) {
+
+		if (!sourceOptions.containsKey(PARTIAL_FILTER_EXPRESSION_KEY)) {
+			return ops;
+		}
+
+		Assert.isInstanceOf(Document.class, sourceOptions.get(PARTIAL_FILTER_EXPRESSION_KEY));
+		return ops.partialFilterExpression(
+				queryMapper.getMappedObject((Document) sourceOptions.get(PARTIAL_FILTER_EXPRESSION_KEY), entity));
+	}
+
+	private static IndexOptions addDefaultCollationIfRequired(IndexOptions ops, MongoPersistentEntity<?> entity) {
+
+		if (ops.getCollation() != null || entity == null || !entity.hasCollation()) {
+			return ops;
+		}
+
+		return ops.collation(entity.getCollation().toMongoCollation());
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/DefaultScriptOperations.java

@@ -42,13 +42,15 @@ import com.mongodb.MongoException;
 import com.mongodb.client.MongoDatabase;
 
 /**
- * Default implementation of {@link ScriptOperations} capable of saving and executing {@link ServerSideJavaScript}.
+ * Default implementation of {@link ScriptOperations} capable of saving and executing {@link ExecutableMongoScript}.
  *
  * @author Christoph Strobl
  * @author Oliver Gierke
  * @author Mark Paluch
  * @since 1.7
+ * @deprecated since 2.2. The {@code eval} command has been removed in MongoDB Server 4.2.0.
  */
+@Deprecated
 class DefaultScriptOperations implements ScriptOperations {
 
 	private static final String SCRIPT_COLLECTION_NAME = "system.js";

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/EntityOperations.java

@@ -21,12 +21,14 @@ import lombok.RequiredArgsConstructor;
 
 import java.util.Collection;
 import java.util.Map;
+import java.util.Optional;
 
 import org.bson.Document;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.mapping.IdentifierAccessor;
 import org.springframework.data.mapping.MappingException;
+import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
@@ -34,15 +36,15 @@ import org.springframework.data.mongodb.core.convert.MongoWriter;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.mongodb.core.mapping.MongoSimpleTypes;
+import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
-import com.mongodb.util.JSONParseException;
-
 /**
  * Common operations performed on an entity in the context of it's mapping metadata.
  *
@@ -151,15 +153,59 @@ class EntityOperations {
 		return ID_FIELD;
 	}
 
+	/**
+	 * Return the name used for {@code $geoNear.distanceField} avoiding clashes with potentially existing properties.
+	 *
+	 * @param domainType must not be {@literal null}.
+	 * @return the name of the distanceField to use. {@literal dis} by default.
+	 * @since 2.2
+	 */
+	public String nearQueryDistanceFieldName(Class<?> domainType) {
+
+		MongoPersistentEntity<?> persistentEntity = context.getPersistentEntity(domainType);
+		if (persistentEntity == null || persistentEntity.getPersistentProperty("dis") == null) {
+			return "dis";
+		}
+
+		String distanceFieldName = "calculated-distance";
+		int counter = 0;
+		while (persistentEntity.getPersistentProperty(distanceFieldName) != null) {
+			distanceFieldName += "-" + (counter++);
+		}
+
+		return distanceFieldName;
+	}
+
 	private static Document parse(String source) {
 
 		try {
 			return Document.parse(source);
-		} catch (JSONParseException | org.bson.json.JsonParseException o_O) {
+		} catch (org.bson.json.JsonParseException o_O) {
 			throw new MappingException("Could not parse given String to save into a JSON document!", o_O);
+		} catch (RuntimeException o_O) {
+
+			// legacy 3.x exception
+			if (ClassUtils.matchesTypeName(o_O.getClass(), "JSONParseException")) {
+				throw new MappingException("Could not parse given String to save into a JSON document!", o_O);
+			}
+			throw o_O;
 		}
 	}
 
+	public <T> TypedOperations<T> forType(@Nullable Class<T> entityClass) {
+
+		if (entityClass != null) {
+
+			MongoPersistentEntity<?> entity = context.getPersistentEntity(entityClass);
+
+			if (entity != null) {
+				return new TypedEntityOperations(entity);
+			}
+
+		}
+		return UntypedOperations.instance();
+	}
+
 	/**
 	 * A representation of information about an entity.
 	 *
@@ -189,6 +235,16 @@ class EntityOperations {
 		 */
 		Query getByIdQuery();
 
+		/**
+		 * Returns the {@link Query} to remove an entity by its {@literal id} and if applicable {@literal version}.
+		 *
+		 * @return the {@link Query} to use for removing the entity. Never {@literal null}.
+		 * @since 2.2
+		 */
+		default Query getRemoveByQuery() {
+			return isVersionedEntity() ? getQueryForVersion() : getByIdQuery();
+		}
+
 		/**
 		 * Returns the {@link Query} to find the entity in its current version.
 		 *
@@ -219,9 +275,11 @@ class EntityOperations {
 		}
 
 		/**
-		 * Returns the value of the version if the entity has a version property, {@literal null} otherwise.
+		 * Returns the value of the version if the entity {@link #isVersionedEntity() has a version property}.
 		 *
-		 * @return
+		 * @return the entity version. Can be {@literal null}.
+		 * @throws IllegalStateException if the entity does not define a {@literal version} property. Make sure to check
+		 *           {@link #isVersionedEntity()}.
 		 */
 		@Nullable
 		Object getVersion();
@@ -235,7 +293,7 @@ class EntityOperations {
 
 		/**
 		 * Returns whether the entity is considered to be new.
-		 * 
+		 *
 		 * @return
 		 * @since 2.1.2
 		 */
@@ -277,8 +335,8 @@ class EntityOperations {
 		/**
 		 * Returns the current version value if the entity has a version property.
 		 *
-		 * @return the current version or {@literal null} in case it's uninitialized or the entity doesn't expose a version
-		 *         property.
+		 * @return the current version or {@literal null} in case it's uninitialized.
+		 * @throws IllegalStateException if the entity does not define a {@literal version} property.
 		 */
 		@Nullable
 		Number getVersion();
@@ -386,7 +444,7 @@ class EntityOperations {
 			return map;
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#isNew()
 		 */
@@ -480,10 +538,10 @@ class EntityOperations {
 		public Query getQueryForVersion() {
 
 			MongoPersistentProperty idProperty = entity.getRequiredIdProperty();
-			MongoPersistentProperty property = entity.getRequiredVersionProperty();
+			MongoPersistentProperty versionProperty = entity.getRequiredVersionProperty();
 
 			return new Query(Criteria.where(idProperty.getName()).is(getId())//
-					.and(property.getName()).is(getVersion()));
+					.and(versionProperty.getName()).is(getVersion()));
 		}
 
 		/*
@@ -557,7 +615,7 @@ class EntityOperations {
 			return propertyAccessor.getBean();
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#isNew()
 		 */
@@ -667,4 +725,102 @@ class EntityOperations {
 			return propertyAccessor.getBean();
 		}
 	}
+
+	/**
+	 * Type-specific operations abstraction.
+	 *
+	 * @author Mark Paluch
+	 * @param <T>
+	 * @since 2.2
+	 */
+	interface TypedOperations<T> {
+
+		/**
+		 * Return the optional {@link Collation} for the underlying entity.
+		 *
+		 * @return
+		 */
+		Optional<Collation> getCollation();
+
+		/**
+		 * Return the optional {@link Collation} from the given {@link Query} and fall back to the collation configured for
+		 * the underlying entity.
+		 *
+		 * @return
+		 */
+		Optional<Collation> getCollation(Query query);
+	}
+
+	/**
+	 * {@link TypedOperations} for generic entities that are not represented with {@link PersistentEntity} (e.g. custom
+	 * conversions).
+	 */
+	@RequiredArgsConstructor
+	enum UntypedOperations implements TypedOperations<Object> {
+
+		INSTANCE;
+
+		@SuppressWarnings({ "unchecked", "rawtypes" })
+		public static <T> TypedOperations<T> instance() {
+			return (TypedOperations) INSTANCE;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation()
+		 */
+		@Override
+		public Optional<Collation> getCollation() {
+			return Optional.empty();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation(org.springframework.data.mongodb.core.query.Query)
+		 */
+		@Override
+		public Optional<Collation> getCollation(Query query) {
+
+			if (query == null) {
+				return Optional.empty();
+			}
+
+			return query.getCollation();
+		}
+	}
+
+	/**
+	 * {@link TypedOperations} backed by {@link MongoPersistentEntity}.
+	 *
+	 * @param <T>
+	 */
+	@RequiredArgsConstructor
+	static class TypedEntityOperations<T> implements TypedOperations<T> {
+
+		private final @NonNull MongoPersistentEntity<T> entity;
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation()
+		 */
+		@Override
+		public Optional<Collation> getCollation() {
+			return Optional.ofNullable(entity.getCollation());
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation(org.springframework.data.mongodb.core.query.Query)
+		 */
+		@Override
+		public Optional<Collation> getCollation(Query query) {
+
+			if (query.getCollation().isPresent()) {
+				return query.getCollation();
+			}
+
+			return Optional.ofNullable(entity.getCollation());
+		}
+	}
+
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ExecutableFindOperationSupport.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.mongodb.core;
 
+import com.mongodb.ReadPreference;
 import lombok.AccessLevel;
 import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
@@ -267,6 +268,11 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			this.limit = Optional.of(limit);
 			return this;
 		}
+
+		@Override
+		public ReadPreference getReadPreference() {
+			return delegate.getReadPreference();
+		}
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ExecutableUpdateOperation.java

@@ -17,8 +17,10 @@ package org.springframework.data.mongodb.core;
 
 import java.util.Optional;
 
+import org.springframework.data.mongodb.core.aggregation.AggregationUpdate;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import org.springframework.lang.Nullable;
 
 import com.mongodb.client.result.UpdateResult;
@@ -151,13 +153,16 @@ public interface ExecutableUpdateOperation {
 	interface UpdateWithUpdate<T> {
 
 		/**
-		 * Set the {@link Update} to be applied.
+		 * Set the {@link UpdateDefinition} to be applied.
 		 *
 		 * @param update must not be {@literal null}.
 		 * @return new instance of {@link TerminatingUpdate}.
 		 * @throws IllegalArgumentException if update is {@literal null}.
+		 * @since 3.0
+		 * @see Update
+		 * @see AggregationUpdate
 		 */
-		TerminatingUpdate<T> apply(Update update);
+		TerminatingUpdate<T> apply(UpdateDefinition update);
 
 		/**
 		 * Specify {@code replacement} object.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ExecutableUpdateOperationSupport.java

@@ -21,7 +21,7 @@ import lombok.RequiredArgsConstructor;
 import lombok.experimental.FieldDefaults;
 
 import org.springframework.data.mongodb.core.query.Query;
-import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -67,7 +67,7 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 		@NonNull MongoTemplate template;
 		@NonNull Class domainType;
 		Query query;
-		@Nullable Update update;
+		@Nullable UpdateDefinition update;
 		@Nullable String collection;
 		@Nullable FindAndModifyOptions findAndModifyOptions;
 		@Nullable FindAndReplaceOptions findAndReplaceOptions;
@@ -76,10 +76,10 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 		/*
 		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithUpdate#apply(Update)
+		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithUpdate#apply(org.springframework.data.mongodb.core.query.UpdateDefinition)
 		 */
 		@Override
-		public TerminatingUpdate<T> apply(Update update) {
+		public TerminatingUpdate<T> apply(UpdateDefinition update) {
 
 			Assert.notNull(update, "Update must not be null!");
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/FindAndModifyOptions.java

@@ -33,6 +33,31 @@ public class FindAndModifyOptions {
 
 	private @Nullable Collation collation;
 
+	private static final FindAndModifyOptions NONE = new FindAndModifyOptions() {
+
+		private static final String ERROR_MSG = "FindAndModifyOptions.none() cannot be changed. Please use FindAndModifyOptions.options() instead.";
+
+		@Override
+		public FindAndModifyOptions returnNew(boolean returnNew) {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+
+		@Override
+		public FindAndModifyOptions upsert(boolean upsert) {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+
+		@Override
+		public FindAndModifyOptions remove(boolean remove) {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+
+		@Override
+		public FindAndModifyOptions collation(@Nullable Collation collation) {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+	};
+
 	/**
 	 * Static factory method to create a FindAndModifyOptions instance
 	 *
@@ -42,9 +67,19 @@ public class FindAndModifyOptions {
 		return new FindAndModifyOptions();
 	}
 
+	/**
+	 * Static factory method returning an unmodifiable {@link FindAndModifyOptions} instance.
+	 *
+	 * @return unmodifiable {@link FindAndModifyOptions} instance.
+	 * @since 2.2
+	 */
+	public static FindAndModifyOptions none() {
+		return NONE;
+	}
+
 	/**
 	 * Create new {@link FindAndModifyOptions} based on option of given {@litearl source}.
-	 * 
+	 *
 	 * @param source can be {@literal null}.
 	 * @return new instance of {@link FindAndModifyOptions}.
 	 * @since 2.0

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/FindAndReplaceOptions.java

@@ -36,6 +36,21 @@ public class FindAndReplaceOptions {
 	private boolean returnNew;
 	private boolean upsert;
 
+	private static final FindAndReplaceOptions NONE = new FindAndReplaceOptions() {
+
+		private static final String ERROR_MSG = "FindAndReplaceOptions.none() cannot be changed. Please use FindAndReplaceOptions.options() instead.";
+
+		@Override
+		public FindAndReplaceOptions returnNew() {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+
+		@Override
+		public FindAndReplaceOptions upsert() {
+			throw new UnsupportedOperationException(ERROR_MSG);
+		}
+	};
+
 	/**
 	 * Static factory method to create a {@link FindAndReplaceOptions} instance.
 	 * <dl>
@@ -51,6 +66,16 @@ public class FindAndReplaceOptions {
 		return new FindAndReplaceOptions();
 	}
 
+	/**
+	 * Static factory method returning an unmodifiable {@link FindAndReplaceOptions} instance.
+	 *
+	 * @return unmodifiable {@link FindAndReplaceOptions} instance.
+	 * @since 2.2
+	 */
+	public static FindAndReplaceOptions none() {
+		return NONE;
+	}
+
 	/**
 	 * Static factory method to create a {@link FindAndReplaceOptions} instance with
 	 * <dl>

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/FindPublisherPreparer.java

@@ -15,20 +15,69 @@
  */
 package org.springframework.data.mongodb.core;
 
+import java.util.function.Function;
+
+import org.bson.Document;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+import com.mongodb.ReadPreference;
 import com.mongodb.reactivestreams.client.FindPublisher;
+import com.mongodb.reactivestreams.client.MongoCollection;
 
 /**
  * Simple callback interface to allow customization of a {@link FindPublisher}.
  *
  * @author Mark Paluch
+ * @author Christoph Strobl
  * @author Konstantin Volivach
  */
-public interface FindPublisherPreparer {
+public interface FindPublisherPreparer extends ReadPreferenceAware {
+
+	/**
+	 * Default {@link FindPublisherPreparer} just passing on the given {@link FindPublisher}.
+	 *
+	 * @since 2.2
+	 */
+	FindPublisherPreparer NO_OP_PREPARER = (findPublisher -> findPublisher);
 
 	/**
 	 * Prepare the given cursor (apply limits, skips and so on). Returns the prepared cursor.
 	 *
 	 * @param findPublisher must not be {@literal null}.
 	 */
-	<T> FindPublisher<T> prepare(FindPublisher<T> findPublisher);
+	FindPublisher<Document> prepare(FindPublisher<Document> findPublisher);
+
+	/**
+	 * Apply query specific settings to {@link MongoCollection} and initate a find operation returning a
+	 * {@link FindPublisher} via the given {@link Function find} function.
+	 *
+	 * @param collection must not be {@literal null}.
+	 * @param find must not be {@literal null}.
+	 * @return
+	 * @throws IllegalArgumentException if one of the required arguments is {@literal null}.
+	 * @since 2.2
+	 */
+	default FindPublisher<Document> initiateFind(MongoCollection<Document> collection,
+			Function<MongoCollection<Document>, FindPublisher<Document>> find) {
+
+		Assert.notNull(collection, "Collection must not be null!");
+		Assert.notNull(find, "Find function must not be null!");
+
+		if (hasReadPreference()) {
+			collection = collection.withReadPreference(getReadPreference());
+		}
+
+		return prepare(find.apply(collection));
+	}
+
+	/**
+	 * @return the {@link ReadPreference} to apply or {@literal null} if none defined.
+	 * @since 2.2
+	 */
+	@Override
+	@Nullable
+	default ReadPreference getReadPreference() {
+		return null;
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MappedDocument.java

@@ -92,7 +92,7 @@ public class MappedDocument {
 	 * mapped to the specific domain type.
 	 *
 	 * @author Christoph Strobl
-	 * @since 2.1.4
+	 * @since 2.2
 	 */
 	class MappedUpdate implements UpdateDefinition {
 
@@ -137,5 +137,14 @@ public class MappedDocument {
 		public Boolean isIsolated() {
 			return delegate.isIsolated();
 		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#getArrayFilters()
+		 */
+		@Override
+		public List<ArrayFilter> getArrayFilters() {
+			return delegate.getArrayFilters();
+		}
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MappingMongoJsonSchemaCreator.java

@@ -0,0 +1,210 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.List;
+
+import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.mapping.Field;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.ObjectJsonSchemaProperty;
+import org.springframework.data.mongodb.core.schema.JsonSchemaObject;
+import org.springframework.data.mongodb.core.schema.JsonSchemaObject.Type;
+import org.springframework.data.mongodb.core.schema.JsonSchemaProperty;
+import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.data.mongodb.core.schema.MongoJsonSchema.MongoJsonSchemaBuilder;
+import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * {@link MongoJsonSchemaCreator} implementation using both {@link MongoConverter} and {@link MappingContext} to obtain
+ * domain type meta information which considers {@link org.springframework.data.mongodb.core.mapping.Field field names}
+ * and {@link org.springframework.data.mongodb.core.convert.MongoCustomConversions custom conversions}.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.2
+ */
+class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
+
+	private final MongoConverter converter;
+	private final MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+
+	/**
+	 * Create a new instance of {@link MappingMongoJsonSchemaCreator}.
+	 *
+	 * @param converter must not be {@literal null}.
+	 */
+	@SuppressWarnings("unchecked")
+	MappingMongoJsonSchemaCreator(MongoConverter converter) {
+
+		Assert.notNull(converter, "Converter must not be null!");
+		this.converter = converter;
+		this.mappingContext = (MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty>) converter
+				.getMappingContext();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.data.mongodb.core.MongoJsonSchemaCreator#createSchemaFor(java.lang.Class)
+	 */
+	@Override
+	public MongoJsonSchema createSchemaFor(Class<?> type) {
+
+		MongoPersistentEntity<?> entity = mappingContext.getRequiredPersistentEntity(type);
+		MongoJsonSchemaBuilder schemaBuilder = MongoJsonSchema.builder();
+
+		List<JsonSchemaProperty> schemaProperties = computePropertiesForEntity(Collections.emptyList(), entity);
+		schemaBuilder.properties(schemaProperties.toArray(new JsonSchemaProperty[0]));
+
+		return schemaBuilder.build();
+
+	}
+
+	private List<JsonSchemaProperty> computePropertiesForEntity(List<MongoPersistentProperty> path,
+			MongoPersistentEntity<?> entity) {
+
+		List<JsonSchemaProperty> schemaProperties = new ArrayList<>();
+
+		for (MongoPersistentProperty nested : entity) {
+
+			List<MongoPersistentProperty> currentPath = new ArrayList<>(path);
+
+			if (path.contains(nested)) { // cycle guard
+				schemaProperties.add(createSchemaProperty(computePropertyFieldName(CollectionUtils.lastElement(currentPath)),
+						Object.class, false));
+				break;
+			}
+
+			currentPath.add(nested);
+			schemaProperties.add(computeSchemaForProperty(currentPath));
+		}
+
+		return schemaProperties;
+	}
+
+	private JsonSchemaProperty computeSchemaForProperty(List<MongoPersistentProperty> path) {
+
+		MongoPersistentProperty property = CollectionUtils.lastElement(path);
+
+		boolean required = isRequiredProperty(property);
+		Class<?> rawTargetType = computeTargetType(property); // target type before conversion
+		Class<?> targetType = converter.getTypeMapper().getWriteTargetTypeFor(rawTargetType); // conversion target type
+
+		if (property.isEntity() && ObjectUtils.nullSafeEquals(rawTargetType, targetType)) {
+			return createObjectSchemaPropertyForEntity(path, property, required);
+		}
+
+		String fieldName = computePropertyFieldName(property);
+
+		if (property.isCollectionLike()) {
+			return createSchemaProperty(fieldName, targetType, required);
+		} else if (property.isMap()) {
+			return createSchemaProperty(fieldName, Type.objectType(), required);
+		} else if (ClassUtils.isAssignable(Enum.class, targetType)) {
+			return createEnumSchemaProperty(fieldName, targetType, required);
+		}
+
+		return createSchemaProperty(fieldName, targetType, required);
+	}
+
+	private JsonSchemaProperty createObjectSchemaPropertyForEntity(List<MongoPersistentProperty> path,
+			MongoPersistentProperty property, boolean required) {
+
+		ObjectJsonSchemaProperty target = JsonSchemaProperty.object(property.getName());
+		List<JsonSchemaProperty> nestedProperties = computePropertiesForEntity(path,
+				mappingContext.getRequiredPersistentEntity(property));
+
+		return createPotentiallyRequiredSchemaProperty(
+				target.properties(nestedProperties.toArray(new JsonSchemaProperty[0])), required);
+	}
+
+	private JsonSchemaProperty createEnumSchemaProperty(String fieldName, Class<?> targetType, boolean required) {
+
+		List<Object> possibleValues = new ArrayList<>();
+
+		for (Object enumValue : EnumSet.allOf((Class) targetType)) {
+			possibleValues.add(converter.convertToMongoType(enumValue));
+		}
+
+		targetType = possibleValues.isEmpty() ? targetType : possibleValues.iterator().next().getClass();
+		return createSchemaProperty(fieldName, targetType, required, possibleValues);
+	}
+
+	JsonSchemaProperty createSchemaProperty(String fieldName, Object type, boolean required) {
+		return createSchemaProperty(fieldName, type, required, Collections.emptyList());
+	}
+
+	JsonSchemaProperty createSchemaProperty(String fieldName, Object type, boolean required,
+			Collection<?> possibleValues) {
+
+		TypedJsonSchemaObject schemaObject = type instanceof Type ? JsonSchemaObject.of(Type.class.cast(type))
+				: JsonSchemaObject.of(Class.class.cast(type));
+
+		if (!CollectionUtils.isEmpty(possibleValues)) {
+			schemaObject = schemaObject.possibleValues(possibleValues);
+		}
+
+		return createPotentiallyRequiredSchemaProperty(JsonSchemaProperty.named(fieldName).with(schemaObject), required);
+	}
+
+	private String computePropertyFieldName(PersistentProperty property) {
+
+		return property instanceof MongoPersistentProperty ? ((MongoPersistentProperty) property).getFieldName()
+				: property.getName();
+	}
+
+	private boolean isRequiredProperty(PersistentProperty property) {
+		return property.getType().isPrimitive();
+	}
+
+	private Class<?> computeTargetType(PersistentProperty<?> property) {
+
+		if (!(property instanceof MongoPersistentProperty)) {
+			return property.getType();
+		}
+
+		MongoPersistentProperty mongoProperty = (MongoPersistentProperty) property;
+		if (!mongoProperty.isIdProperty()) {
+			return mongoProperty.getFieldType();
+		}
+
+		if (mongoProperty.hasExplicitWriteTarget()) {
+			return mongoProperty.getRequiredAnnotation(Field.class).targetType().getJavaClass();
+		}
+
+		return mongoProperty.getFieldType() != mongoProperty.getActualType() ? Object.class : mongoProperty.getFieldType();
+	}
+
+	static JsonSchemaProperty createPotentiallyRequiredSchemaProperty(JsonSchemaProperty property, boolean required) {
+
+		if (!required) {
+			return property;
+		}
+
+		return JsonSchemaProperty.required(property);
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoAdmin.java

@@ -34,14 +34,29 @@ import com.mongodb.client.MongoDatabase;
 @ManagedResource(description = "Mongo Admin Operations")
 public class MongoAdmin implements MongoAdminOperations {
 
-	private final MongoClient mongoClient;
+	private final Object mongoClient;
 
+	/**
+	 * @param mongoClient
+	 * @deprecated since 2.2 in favor of {@link MongoAdmin#MongoAdmin(com.mongodb.client.MongoClient)}.
+	 */
+	@Deprecated
 	public MongoAdmin(MongoClient mongoClient) {
 
 		Assert.notNull(mongoClient, "MongoClient must not be null!");
 		this.mongoClient = mongoClient;
 	}
 
+	/**
+	 * @param client the underlying {@link com.mongodb.client.MongoClient} used for data access.
+	 * @since 2.2
+	 */
+	public MongoAdmin(com.mongodb.client.MongoClient client) {
+
+		Assert.notNull(client, "Client must not be null!");
+		this.mongoClient = client;
+	}
+
 	/* (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.core.MongoAdminOperations#dropDatabase(java.lang.String)
 	 */
@@ -73,6 +88,11 @@ public class MongoAdmin implements MongoAdminOperations {
 	}
 
 	MongoDatabase getDB(String databaseName) {
-		return mongoClient.getDatabase(databaseName);
+
+		if (mongoClient instanceof MongoClient) {
+			return ((MongoClient) mongoClient).getDatabase(databaseName);
+		}
+
+		return ((com.mongodb.client.MongoClient) mongoClient).getDatabase(databaseName);
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoClientFactoryBean.java

@@ -38,7 +38,11 @@ import com.mongodb.ServerAddress;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @since 1.7
+ * @deprecated since 2.2 - There is no replacement for this {@link org.springframework.beans.factory.FactoryBean} at
+ *             this time. However moving forward the {@link org.springframework.beans.factory.FactoryBean} will be
+ *             suitable to provide instances of {@link com.mongodb.client.MongoClient}.
  */
+@Deprecated
 public class MongoClientFactoryBean extends AbstractFactoryBean<MongoClient> implements PersistenceExceptionTranslator {
 
 	private static final PersistenceExceptionTranslator DEFAULT_EXCEPTION_TRANSLATOR = new MongoExceptionTranslator();

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoClientOptionsFactoryBean.java

@@ -22,6 +22,7 @@ import org.springframework.beans.factory.config.AbstractFactoryBean;
 import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.lang.Nullable;
 
+import com.mongodb.AutoEncryptionSettings;
 import com.mongodb.DBDecoderFactory;
 import com.mongodb.DBEncoderFactory;
 import com.mongodb.MongoClient;
@@ -36,12 +37,17 @@ import com.mongodb.WriteConcern;
  * @author Oliver Gierke
  * @author Mark Paluch
  * @since 1.7
+ * @deprecated since 2.2 - There is no replacement for this {@link org.springframework.beans.factory.FactoryBean}.
+ *             However moving forward there will be a dedicated factory bean for {@link com.mongodb.MongoClientSettings}
+ *             replacing {@link MongoClientOptions}.
  */
+@Deprecated
 public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClientOptions> {
 
 	private static final MongoClientOptions DEFAULT_MONGO_OPTIONS = MongoClientOptions.builder().build();
 
-	private @Nullable String description = DEFAULT_MONGO_OPTIONS.getDescription();
+	// TODO: Mongo Driver 4 - use application name insetad of description if not available
+	private @Nullable String description = DEFAULT_MONGO_OPTIONS.getApplicationName();
 	private int minConnectionsPerHost = DEFAULT_MONGO_OPTIONS.getMinConnectionsPerHost();
 	private int connectionsPerHost = DEFAULT_MONGO_OPTIONS.getConnectionsPerHost();
 	private int threadsAllowedToBlockForConnectionMultiplier = DEFAULT_MONGO_OPTIONS
@@ -51,6 +57,8 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 	private int maxConnectionLifeTime = DEFAULT_MONGO_OPTIONS.getMaxConnectionLifeTime();
 	private int connectTimeout = DEFAULT_MONGO_OPTIONS.getConnectTimeout();
 	private int socketTimeout = DEFAULT_MONGO_OPTIONS.getSocketTimeout();
+
+	// TODO: Mongo Driver 4 - check if available
 	private boolean socketKeepAlive = DEFAULT_MONGO_OPTIONS.isSocketKeepAlive();
 	private @Nullable ReadPreference readPreference = DEFAULT_MONGO_OPTIONS.getReadPreference();
 	private DBDecoderFactory dbDecoderFactory = DEFAULT_MONGO_OPTIONS.getDbDecoderFactory();
@@ -58,6 +66,8 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 	private @Nullable WriteConcern writeConcern = DEFAULT_MONGO_OPTIONS.getWriteConcern();
 	private @Nullable SocketFactory socketFactory = DEFAULT_MONGO_OPTIONS.getSocketFactory();
 	private boolean cursorFinalizerEnabled = DEFAULT_MONGO_OPTIONS.isCursorFinalizerEnabled();
+
+	// TODO: Mongo Driver 4 - remove this option
 	private boolean alwaysUseMBeans = DEFAULT_MONGO_OPTIONS.isAlwaysUseMBeans();
 	private int heartbeatFrequency = DEFAULT_MONGO_OPTIONS.getHeartbeatFrequency();
 	private int minHeartbeatFrequency = DEFAULT_MONGO_OPTIONS.getMinHeartbeatFrequency();
@@ -68,12 +78,14 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 
 	private boolean ssl;
 	private @Nullable SSLSocketFactory sslSocketFactory;
+	private @Nullable AutoEncryptionSettings autoEncryptionSettings;
 
 	/**
 	 * Set the {@link MongoClient} description.
 	 *
 	 * @param description
 	 */
+	// TODO: Mongo Driver 4 - deprecate that one and add application name
 	public void setDescription(@Nullable String description) {
 		this.description = description;
 	}
@@ -235,7 +247,7 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 	}
 
 	/**
-	 * This controls if the driver should us an SSL connection. Defaults to |@literal false}.
+	 * This controls if the driver should us an SSL connection. Defaults to {@literal false}.
 	 *
 	 * @param ssl
 	 */
@@ -266,6 +278,16 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 		this.serverSelectionTimeout = serverSelectionTimeout;
 	}
 
+	/**
+	 * Set the {@link AutoEncryptionSettings} to be used.
+	 *
+	 * @param autoEncryptionSettings can be {@literal null}.
+	 * @since 2.2
+	 */
+	public void setAutoEncryptionSettings(@Nullable AutoEncryptionSettings autoEncryptionSettings) {
+		this.autoEncryptionSettings = autoEncryptionSettings;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.config.AbstractFactoryBean#createInstance()
@@ -285,7 +307,7 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 				.cursorFinalizerEnabled(cursorFinalizerEnabled) //
 				.dbDecoderFactory(dbDecoderFactory) //
 				.dbEncoderFactory(dbEncoderFactory) //
-				.description(description) //
+				.applicationName(description) // TODO: Mongo Driver 4 - use application name if description not available
 				.heartbeatConnectTimeout(heartbeatConnectTimeout) //
 				.heartbeatFrequency(heartbeatFrequency) //
 				.heartbeatSocketTimeout(heartbeatSocketTimeout) //
@@ -297,8 +319,10 @@ public class MongoClientOptionsFactoryBean extends AbstractFactoryBean<MongoClie
 				.readPreference(readPreference) //
 				.requiredReplicaSetName(requiredReplicaSetName) //
 				.serverSelectionTimeout(serverSelectionTimeout) //
-				.socketFactory(socketFactoryToUse) //
-				.socketKeepAlive(socketKeepAlive) //
+				.sslEnabled(ssl) //
+				.autoEncryptionSettings(autoEncryptionSettings) //
+				.socketFactory(socketFactoryToUse) // TODO: Mongo Driver 4 -
+				.socketKeepAlive(socketKeepAlive) // TODO: Mongo Driver 4 - remove if not available
 				.socketTimeout(socketTimeout) //
 				.threadsAllowedToBlockForConnectionMultiplier(threadsAllowedToBlockForConnectionMultiplier) //
 				.writeConcern(writeConcern).build();

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoDbFactorySupport.java

@@ -265,7 +265,7 @@ public abstract class MongoDbFactorySupport<C> implements MongoDbFactory {
 			factory.addAdvice(new SessionAwareMethodInterceptor<>(session, target, ClientSession.class, MongoDatabase.class,
 					this::proxyDatabase, MongoCollection.class, this::proxyCollection));
 
-			return targetType.cast(factory.getProxy(target.getClass().getClassLoader()));
+			return targetType.cast(factory.getProxy());
 		}
 	}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoEncryptionSettingsFactoryBean.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import java.util.Collections;
+import java.util.Map;
+
+import org.bson.BsonDocument;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.lang.Nullable;
+
+import com.mongodb.AutoEncryptionSettings;
+import com.mongodb.MongoClientSettings;
+
+/**
+ * {@link FactoryBean} for creating {@link AutoEncryptionSettings} using the {@link AutoEncryptionSettings.Builder}.
+ *
+ * @author Christoph Strobl
+ * @since 2.2
+ */
+public class MongoEncryptionSettingsFactoryBean implements FactoryBean<AutoEncryptionSettings> {
+
+	private boolean bypassAutoEncryption;
+	private String keyVaultNamespace;
+	private Map<String, Object> extraOptions;
+	private MongoClientSettings keyVaultClientSettings;
+	private Map<String, Map<String, Object>> kmsProviders;
+	private Map<String, BsonDocument> schemaMap;
+
+	/**
+	 * @param bypassAutoEncryption
+	 * @see AutoEncryptionSettings.Builder#bypassAutoEncryption(boolean)
+	 */
+	public void setBypassAutoEncryption(boolean bypassAutoEncryption) {
+		this.bypassAutoEncryption = bypassAutoEncryption;
+	}
+
+	/**
+	 * @param extraOptions
+	 * @see AutoEncryptionSettings.Builder#extraOptions(Map)
+	 */
+	public void setExtraOptions(Map<String, Object> extraOptions) {
+		this.extraOptions = extraOptions;
+	}
+
+	/**
+	 * @param keyVaultNamespace
+	 * @see AutoEncryptionSettings.Builder#keyVaultNamespace(String)
+	 */
+	public void setKeyVaultNamespace(String keyVaultNamespace) {
+		this.keyVaultNamespace = keyVaultNamespace;
+	}
+
+	/**
+	 * @param keyVaultClientSettings
+	 * @see AutoEncryptionSettings.Builder#keyVaultMongoClientSettings(MongoClientSettings)
+	 */
+	public void setKeyVaultClientSettings(MongoClientSettings keyVaultClientSettings) {
+		this.keyVaultClientSettings = keyVaultClientSettings;
+	}
+
+	/**
+	 * @param kmsProviders
+	 * @see AutoEncryptionSettings.Builder#kmsProviders(Map)
+	 */
+	public void setKmsProviders(Map<String, Map<String, Object>> kmsProviders) {
+		this.kmsProviders = kmsProviders;
+	}
+
+	/**
+	 * @param schemaMap
+	 * @see AutoEncryptionSettings.Builder#schemaMap(Map)
+	 */
+	public void setSchemaMap(Map<String, BsonDocument> schemaMap) {
+		this.schemaMap = schemaMap;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see  org.springframework.beans.factory.FactoryBean#getObject()
+	 */
+	@Override
+	public AutoEncryptionSettings getObject() {
+
+		return AutoEncryptionSettings.builder() //
+				.bypassAutoEncryption(bypassAutoEncryption) //
+				.keyVaultNamespace(keyVaultNamespace) //
+				.keyVaultMongoClientSettings(keyVaultClientSettings) //
+				.kmsProviders(orEmpty(kmsProviders)) //
+				.extraOptions(orEmpty(extraOptions)) //
+				.schemaMap(orEmpty(schemaMap)) //
+				.build();
+	}
+
+	private <K, V> Map<K, V> orEmpty(@Nullable Map<K, V> source) {
+		return source != null ? source : Collections.emptyMap();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see  org.springframework.beans.factory.FactoryBean#getObjectType()
+	 */
+	@Override
+	public Class<?> getObjectType() {
+		return AutoEncryptionSettings.class;
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoJsonSchemaCreator.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.util.Assert;
+
+/**
+ * {@link MongoJsonSchemaCreator} extracts the {@link MongoJsonSchema} for a given {@link Class} by applying the
+ * following mapping rules.
+ * <p>
+ * <strong>Required Properties</strong>
+ * <ul>
+ * <li>Properties of primitive type</li>
+ * </ul>
+ * <strong>Ignored Properties</strong>
+ * <ul>
+ * <li>All properties annotated with {@link org.springframework.data.annotation.Transient}</li>
+ * </ul>
+ * <strong>Property Type Mapping</strong>
+ * <ul>
+ * <li>{@link java.lang.Object} -> {@code type : 'object'}</li>
+ * <li>{@link java.util.Arrays} -> {@code type : 'array'}</li>
+ * <li>{@link java.util.Collection} -> {@code type : 'array'}</li>
+ * <li>{@link java.util.Map} -> {@code type : 'object'}</li>
+ * <li>{@link java.lang.Enum} -> {@code type : 'string', enum : [the enum values]}</li>
+ * <li>Simple Types -> {@code type : 'the corresponding bson type' }</li>
+ * <li>Domain Types -> {@code type : 'object', properties : &#123;the types properties&#125; }</li>
+ * </ul>
+ * <br />
+ * {@link org.springframework.data.annotation.Id _id} properties using types that can be converted into
+ * {@link org.bson.types.ObjectId} like {@link String} will be mapped to {@code type : 'object'} unless there is more
+ * specific information available via the {@link org.springframework.data.mongodb.core.mapping.MongoId} annotation.
+ * </p>
+ *
+ * @author Christoph Strobl
+ * @since 2.2
+ */
+public interface MongoJsonSchemaCreator {
+
+	/**
+	 * Create the {@link MongoJsonSchema} for the given {@link Class type}.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return never {@literal null}.
+	 */
+	MongoJsonSchema createSchemaFor(Class<?> type);
+
+	/**
+	 * Creates a new {@link MongoJsonSchemaCreator} that is aware of conversions applied by the given
+	 * {@link MongoConverter}.
+	 *
+	 * @param mongoConverter must not be {@literal null}.
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 */
+	static MongoJsonSchemaCreator create(MongoConverter mongoConverter) {
+
+		Assert.notNull(mongoConverter, "MongoConverter must not be null!");
+		return new MappingMongoJsonSchemaCreator(mongoConverter);
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java

@@ -27,6 +27,7 @@ import org.springframework.data.mongodb.core.BulkOperations.BulkMode;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
 import org.springframework.data.mongodb.core.aggregation.AggregationResults;
+import org.springframework.data.mongodb.core.aggregation.AggregationUpdate;
 import org.springframework.data.mongodb.core.aggregation.TypedAggregation;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
@@ -40,6 +41,7 @@ import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import org.springframework.data.util.CloseableIterator;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -57,7 +59,7 @@ import com.mongodb.client.result.UpdateResult;
  * Interface that specifies a basic set of MongoDB operations. Implemented by {@link MongoTemplate}. Not often used but
  * a useful option for extensibility and testability (as it can be easily mocked, stubbed, or be the target of a JDK
  * proxy).
- * <p />
+ * <p/>
  * <strong>NOTE:</strong> Some operations cannot be executed within a MongoDB transaction. Please refer to the MongoDB
  * specific documentation to learn more about <a href="https://docs.mongodb.com/manual/core/transactions/">Multi
  * Document Transactions</a>.
@@ -175,7 +177,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Obtain a {@link ClientSession session} bound instance of {@link SessionScoped} binding the {@link ClientSession}
 	 * provided by the given {@link Supplier} to each and every command issued against MongoDB.
-	 * <p />
+	 * <p/>
 	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle. Use the
 	 * {@link SessionScoped#execute(SessionCallback, Consumer)} hook to potentially close the {@link ClientSession}.
 	 *
@@ -211,7 +213,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Obtain a {@link ClientSession} bound instance of {@link MongoOperations}.
-	 * <p />
+	 * <p/>
 	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle.
 	 *
 	 * @param session must not be {@literal null}.
@@ -362,7 +364,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @return
 	 * @since 1.7
+	 * @deprecated since 2.2. The {@code eval} command has been removed without replacement in MongoDB Server 4.2.0.
 	 */
+	@Deprecated
 	ScriptOperations scriptOps();
 
 	/**
@@ -434,7 +438,11 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *          reduce function.
 	 * @param entityClass The parametrized type of the returned list
 	 * @return The results of the group operation
+	 * @deprecated since 2.2. The {@code group} command has been removed in MongoDB Server 4.2.0. <br />
+	 *             Please use {@link #aggregate(TypedAggregation, String, Class) } with a
+	 *             {@link org.springframework.data.mongodb.core.aggregation.GroupOperation} instead.
 	 */
+	@Deprecated
 	<T> GroupByResults<T> group(String inputCollectionName, GroupBy groupBy, Class<T> entityClass);
 
 	/**
@@ -449,7 +457,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *          reduce function.
 	 * @param entityClass The parametrized type of the returned list
 	 * @return The results of the group operation
+	 * @deprecated since 2.2. The {@code group} command has been removed in MongoDB Server 4.2.0. <br />
+	 *             Please use {@link #aggregate(TypedAggregation, String, Class) } with a
+	 *             {@link org.springframework.data.mongodb.core.aggregation.GroupOperation} and
+	 *             {@link org.springframework.data.mongodb.core.aggregation.MatchOperation} instead.
 	 */
+	@Deprecated
 	<T> GroupByResults<T> group(@Nullable Criteria criteria, String inputCollectionName, GroupBy groupBy,
 			Class<T> entityClass);
 
@@ -637,24 +650,52 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * information to determine the collection the query is ran against. Note, that MongoDB limits the number of results
 	 * by default. Make sure to add an explicit limit to the {@link NearQuery} if you expect a particular number of
 	 * results.
+	 * <p>
+	 * MongoDB 4.2 has removed the {@code geoNear} command. This method uses since version 2.2 aggregations and the
+	 * {@code $geoNear} aggregation command to emulate {@code geoNear} command functionality. We recommend using
+	 * aggregations directly:
+	 * </p>
+	 *
+	 * <pre class="code">
+	 * TypedAggregation&lt;T&gt; geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, "dis"))
+	 * 		.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
+	 * AggregationResults&lt;Document&gt; results = aggregate(geoNear, Document.class);
+	 * </pre>
 	 *
 	 * @param near must not be {@literal null}.
 	 * @param entityClass must not be {@literal null}.
 	 * @return
+	 * @deprecated since 2.2. The {@code eval} command has been removed in MongoDB Server 4.2.0. Use Aggregations with
+	 *             {@link Aggregation#geoNear(NearQuery, String)} instead.
 	 */
+	@Deprecated
 	<T> GeoResults<T> geoNear(NearQuery near, Class<T> entityClass);
 
 	/**
 	 * Returns {@link GeoResults} for all entities matching the given {@link NearQuery}. Note, that MongoDB limits the
 	 * number of results by default. Make sure to add an explicit limit to the {@link NearQuery} if you expect a
 	 * particular number of results.
+	 * <p>
+	 * MongoDB 4.2 has removed the {@code geoNear} command. This method uses since version 2.2 aggregations and the
+	 * {@code $geoNear} aggregation command to emulate {@code geoNear} command functionality. We recommend using
+	 * aggregations directly:
+	 * </p>
+	 *
+	 * <pre class="code">
+	 * TypedAggregation&lt;T&gt; geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, "dis"))
+	 * 		.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
+	 * AggregationResults&lt;Document&gt; results = aggregate(geoNear, Document.class);
+	 * </pre>
 	 *
 	 * @param near must not be {@literal null}.
 	 * @param entityClass must not be {@literal null}.
 	 * @param collectionName the collection to trigger the query against. If no collection name is given the entity class
 	 *          will be inspected. Must not be {@literal null} nor empty.
 	 * @return
+	 * @deprecated since 2.2. The {@code eval} command has been removed in MongoDB Server 4.2.0. Use Aggregations with
+	 *             {@link Aggregation#geoNear(NearQuery, String)} instead.
 	 */
+	@Deprecated
 	<T> GeoResults<T> geoNear(NearQuery near, Class<T> entityClass, String collectionName);
 
 	/**
@@ -844,12 +885,15 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @return the converted object that was updated before it was updated or {@literal null}, if not found.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
 	@Nullable
-	<T> T findAndModify(Query query, Update update, Class<T> entityClass);
+	<T> T findAndModify(Query query, UpdateDefinition update, Class<T> entityClass);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
@@ -857,13 +901,16 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
 	 * @return the converted object that was updated before it was updated or {@literal null}, if not found.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
 	@Nullable
-	<T> T findAndModify(Query query, Update update, Class<T> entityClass, String collectionName);
+	<T> T findAndModify(Query query, UpdateDefinition update, Class<T> entityClass, String collectionName);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
@@ -872,15 +919,18 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification.
-	 * @param update the {@link Update} to apply on matching documents.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents.
 	 * @param options the {@link FindAndModifyOptions} holding additional information.
 	 * @param entityClass the parametrized type.
 	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
 	 *         {@link FindAndModifyOptions#isReturnNew()} this will either be the object as it was before the update or as
 	 *         it is after the update.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
 	@Nullable
-	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass);
+	<T> T findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
@@ -889,16 +939,19 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
 	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
 	 *         {@link FindAndModifyOptions#isReturnNew()} this will either be the object as it was before the update or as
 	 *         it is after the update.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
 	@Nullable
-	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
+	<T> T findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass,
 			String collectionName);
 
 	/**
@@ -1101,6 +1154,11 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the collection of the given entity class.
+	 * <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -1112,7 +1170,11 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Returns the number of documents for the given {@link Query} querying the given collection. The given {@link Query}
 	 * must solely consist of document field references as we lack type information to map potential property references
-	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support.
+	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support. <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
@@ -1123,7 +1185,11 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the given collection using the given entity
-	 * class to map the given {@link Query}.
+	 * class to map the given {@link Query}. <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -1141,8 +1207,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 * <p/>
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
@@ -1203,8 +1269,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
@@ -1234,99 +1300,112 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document. <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, FindAndModifyOptions, Class, String)} instead.
+	 * Use {@link #findAndModify(Query, UpdateDefinition, FindAndModifyOptions, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult upsert(Query query, Update update, Class<?> entityClass);
+	UpdateResult upsert(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #upsert(Query, Update, Class, String)} to get full type specific support.
-	 * <br />
+	 * domain type information. Use {@link #upsert(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support. <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, FindAndModifyOptions, Class, String)} instead.
+	 * Use {@link #findAndModify(Query, UpdateDefinition, FindAndModifyOptions, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult upsert(Query query, Update update, String collectionName);
+	UpdateResult upsert(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
-	 * combining the query document and the update document. <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, FindAndModifyOptions, Class, String)} instead.
-	 * 
+	 * combining the query document and the update document.
+	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult upsert(Query query, Update update, Class<?> entityClass, String collectionName);
+	UpdateResult upsert(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the collection of the entity class that matches the query document with
-	 * the provided update document. <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class)} instead.
+	 * the provided update document.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateFirst(Query query, Update update, Class<?> entityClass);
+	UpdateResult updateFirst(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
 	 * the provided updated document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #updateFirst(Query, Update, Class, String)} to get full type specific support.
+	 * domain type information. Use {@link #updateFirst(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support.
 	 * <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
 	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateFirst(Query query, Update update, String collectionName);
+	UpdateResult updateFirst(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
 	 * the provided updated document. <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateFirst(Query query, Update update, Class<?> entityClass, String collectionName);
+	UpdateResult updateFirst(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
@@ -1334,27 +1413,34 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateMulti(Query query, Update update, Class<?> entityClass);
+	UpdateResult updateMulti(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Updates all objects that are found in the specified collection that matches the query document criteria with the
 	 * provided updated document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #updateMulti(Query, Update, Class, String)} to get full type specific support.
+	 * domain type information. Use {@link #updateMulti(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateMulti(Query query, Update update, String collectionName);
+	UpdateResult updateMulti(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
@@ -1362,16 +1448,22 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	UpdateResult updateMulti(Query query, Update update, Class<?> entityClass, String collectionName);
+	UpdateResult updateMulti(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
-	 * Remove the given object from the collection by id.
+	 * Remove the given object from the collection by {@literal id} and (if applicable) its
+	 * {@link org.springframework.data.annotation.Version}. <br />
+	 * Use {@link DeleteResult#getDeletedCount()} for insight whether an {@link DeleteResult#wasAcknowledged()
+	 * acknowledged} remove operation was successful or not.
 	 *
 	 * @param object must not be {@literal null}.
 	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
@@ -1379,7 +1471,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	DeleteResult remove(Object object);
 
 	/**
-	 * Removes the given object from the given collection.
+	 * Removes the given object from the given collection by {@literal id} and (if applicable) its
+	 * {@link org.springframework.data.annotation.Version}. <br />
+	 * Use {@link DeleteResult#getDeletedCount()} for insight whether an {@link DeleteResult#wasAcknowledged()
+	 * acknowledged} remove operation was successful or not.
 	 *
 	 * @param object must not be {@literal null}.
 	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveChangeStreamOperation.java

@@ -0,0 +1,200 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import reactor.core.publisher.Flux;
+
+import java.time.Instant;
+import java.util.function.Consumer;
+
+import org.bson.BsonTimestamp;
+import org.bson.BsonValue;
+import org.springframework.data.mongodb.core.ChangeStreamOptions.ChangeStreamOptionsBuilder;
+import org.springframework.data.mongodb.core.aggregation.Aggregation;
+import org.springframework.data.mongodb.core.query.CriteriaDefinition;
+
+/**
+ * {@link ReactiveChangeStreamOperation} allows creation and execution of reactive MongoDB
+ * <a href="https://docs.mongodb.com/manual/changeStreams/">Change Stream</a> operations in a fluent API style. <br />
+ * The starting {@literal domainType} is used for mapping a potentially given
+ * {@link org.springframework.data.mongodb.core.aggregation.TypedAggregation} used for filtering. By default, the
+ * originating {@literal domainType} is also used for mapping back the result from the {@link org.bson.Document}.
+ * However, it is possible to define an different {@literal returnType} via {@code as}.<br />
+ * The collection to operate on is optional in which case call collection with the actual database are watched, use
+ * {@literal watchCollection} to define a fixed collection.
+ *
+ * <pre>
+ *     <code>
+ *         changeStream(Jedi.class)
+ *             .watchCollection("star-wars")
+ *             .filter(where("operationType").is("insert"))
+ *             .resumeAt(Instant.now())
+ *             .listen();
+ *     </code>
+ * </pre>
+ *
+ * @author Christoph Strobl
+ * @since 2.2
+ */
+public interface ReactiveChangeStreamOperation {
+
+	/**
+	 * Start creating a change stream operation for the given {@literal domainType} watching all collections within the
+	 * database. <br />
+	 * Consider limiting events be defining a {@link ChangeStreamWithCollection#watchCollection(String) collection} and/or
+	 * {@link ChangeStreamWithFilterAndProjection#filter(CriteriaDefinition) filter}.
+	 *
+	 * @param domainType must not be {@literal null}. Use {@link org.bson.Document} to obtain raw elements.
+	 * @return new instance of {@link ReactiveChangeStream}. Never {@literal null}.
+	 * @throws IllegalArgumentException if domainType is {@literal null}.
+	 */
+	<T> ReactiveChangeStream<T> changeStream(Class<T> domainType);
+
+	/**
+	 * Compose change stream execution by calling one of the terminating methods.
+	 */
+	interface TerminatingChangeStream<T> {
+
+		/**
+		 * Start listening to changes. The stream will not be completed unless the {@link org.reactivestreams.Subscription}
+		 * is {@link org.reactivestreams.Subscription#cancel() canceled}.
+		 * <p />
+		 * However, the stream may become dead, or invalid, if all watched collections, databases are dropped.
+		 */
+		Flux<ChangeStreamEvent<T>> listen();
+	}
+
+	/**
+	 * Collection override (optional).
+	 */
+	interface ChangeStreamWithCollection<T> {
+
+		/**
+		 * Explicitly set the name of the collection to watch.<br />
+		 * Skip this step to watch all collections within the database.
+		 *
+		 * @param collection must not be {@literal null} nor {@literal empty}.
+		 * @return new instance of {@link ChangeStreamWithFilterAndProjection}.
+		 * @throws IllegalArgumentException if {@code collection} is {@literal null}.
+		 */
+		ChangeStreamWithFilterAndProjection<T> watchCollection(String collection);
+
+		/**
+		 * Set the the collection to watch. Collection name is derived from the {@link Class entityClass}.<br />
+		 * Skip this step to watch all collections within the database.
+		 *
+		 * @param entityClass must not be {@literal null}.
+		 * @return new instance of {@link ChangeStreamWithFilterAndProjection}.
+		 * @throws IllegalArgumentException if {@code entityClass} is {@literal null}.
+		 */
+		ChangeStreamWithFilterAndProjection<T> watchCollection(Class<?> entityClass);
+	}
+
+	/**
+	 * Provide a filter for limiting results (optional).
+	 */
+	interface ChangeStreamWithFilterAndProjection<T> extends ResumingChangeStream<T>, TerminatingChangeStream<T> {
+
+		/**
+		 * Use an {@link Aggregation} to filter matching events.
+		 *
+		 * @param by must not be {@literal null}.
+		 * @return new instance of {@link ChangeStreamWithFilterAndProjection}.
+		 * @throws IllegalArgumentException if the given {@link Aggregation} is {@literal null}.
+		 */
+		ChangeStreamWithFilterAndProjection<T> filter(Aggregation by);
+
+		/**
+		 * Use a {@link CriteriaDefinition critera} to filter matching events via an
+		 * {@link org.springframework.data.mongodb.core.aggregation.MatchOperation}.
+		 *
+		 * @param by must not be {@literal null}.
+		 * @return new instance of {@link ChangeStreamWithFilterAndProjection}.
+		 * @throws IllegalArgumentException if the given {@link CriteriaDefinition} is {@literal null}.
+		 */
+		ChangeStreamWithFilterAndProjection<T> filter(CriteriaDefinition by);
+
+		/**
+		 * Define the target type fields should be mapped to.
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link ChangeStreamWithFilterAndProjection}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> ChangeStreamWithFilterAndProjection<R> as(Class<R> resultType);
+	}
+
+	/**
+	 * Resume a change stream. (optional).
+	 */
+	interface ResumingChangeStream<T> extends TerminatingChangeStream<T> {
+
+		/**
+		 * Resume the change stream at a given point.
+		 *
+		 * @param token an {@link Instant} or {@link BsonTimestamp}
+		 * @return new instance of {@link TerminatingChangeStream}.
+		 * @see ChangeStreamOptionsBuilder#resumeAt(Instant)
+		 * @see ChangeStreamOptionsBuilder#resumeAt(BsonTimestamp)
+		 * @throws IllegalArgumentException if the given beacon is neither {@link Instant} nor {@link BsonTimestamp}.
+		 */
+		TerminatingChangeStream<T> resumeAt(Object token);
+
+		/**
+		 * Resume the change stream after a given point.
+		 *
+		 * @param token an {@link Instant} or {@link BsonTimestamp}
+		 * @return new instance of {@link TerminatingChangeStream}.
+		 * @see ChangeStreamOptionsBuilder#resumeAfter(BsonValue)
+		 * @see ChangeStreamOptionsBuilder#resumeToken(BsonValue)
+		 * @throws IllegalArgumentException if the given beacon not a {@link BsonValue}.
+		 */
+		TerminatingChangeStream<T> resumeAfter(Object token);
+
+		/**
+		 * Start the change stream after a given point.
+		 *
+		 * @param token an {@link Instant} or {@link BsonTimestamp}
+		 * @return new instance of {@link TerminatingChangeStream}.
+		 * @see ChangeStreamOptionsBuilder#startAfter(BsonValue) (BsonValue)
+		 * @throws IllegalArgumentException if the given beacon not a {@link BsonValue}.
+		 */
+		TerminatingChangeStream<T> startAfter(Object token);
+	}
+
+	/**
+	 * Provide some options.
+	 */
+	interface ChangeStreamWithOptions<T> {
+
+		/**
+		 * Provide some options via the callback by modifying the given {@link ChangeStreamOptionsBuilder}. Previously
+		 * defined options like a {@link ResumingChangeStream#resumeAfter(Object) resumeToken} are carried over to the
+		 * builder and can be overwritten via eg. {@link ChangeStreamOptionsBuilder#resumeToken(BsonValue)}.
+		 *
+		 * @param optionsConsumer never {@literal null}.
+		 * @return new instance of {@link ReactiveChangeStream}.
+		 */
+		ReactiveChangeStream<T> withOptions(Consumer<ChangeStreamOptionsBuilder> optionsConsumer);
+	}
+
+	/**
+	 * {@link ReactiveChangeStream} provides methods for constructing change stream operations in a fluent way.
+	 */
+	interface ReactiveChangeStream<T> extends ChangeStreamWithOptions<T>, ChangeStreamWithCollection<T>,
+			TerminatingChangeStream<T>, ResumingChangeStream<T>, ChangeStreamWithFilterAndProjection<T> {}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveChangeStreamOperationSupport.java

@@ -0,0 +1,230 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import reactor.core.publisher.Flux;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.function.Consumer;
+
+import org.bson.BsonTimestamp;
+import org.bson.BsonValue;
+import org.bson.Document;
+import org.springframework.data.mongodb.core.ChangeStreamOptions.ChangeStreamOptionsBuilder;
+import org.springframework.data.mongodb.core.aggregation.Aggregation;
+import org.springframework.data.mongodb.core.aggregation.MatchOperation;
+import org.springframework.data.mongodb.core.query.CriteriaDefinition;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+/**
+ * @author Christoph Strobl
+ * @since 2.2
+ */
+class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperation {
+
+	private final ReactiveMongoTemplate template;
+
+	/**
+	 * @param template must not be {@literal null}.
+	 */
+	ReactiveChangeStreamOperationSupport(ReactiveMongoTemplate template) {
+		this.template = template;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation#changeStream(java.lang.Class)
+	 */
+	@Override
+	public <T> ReactiveChangeStream<T> changeStream(Class<T> domainType) {
+
+		Assert.notNull(domainType, "DomainType must not be null!");
+		return new ReactiveChangeStreamSupport<>(template, domainType, domainType, null, null);
+	}
+
+	static class ReactiveChangeStreamSupport<T>
+			implements ReactiveChangeStream<T>, ChangeStreamWithFilterAndProjection<T> {
+
+		private final ReactiveMongoTemplate template;
+		private final Class<?> domainType;
+		private final Class<T> returnType;
+		private final @Nullable String collection;
+		private final @Nullable ChangeStreamOptions options;
+
+		private ReactiveChangeStreamSupport(ReactiveMongoTemplate template, Class<?> domainType, Class<T> returnType,
+				@Nullable String collection, @Nullable ChangeStreamOptions options) {
+
+			this.template = template;
+			this.domainType = domainType;
+			this.returnType = returnType;
+			this.collection = collection;
+			this.options = options;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithCollection#watchCollection(java.lang.String)
+		 */
+		@Override
+		public ChangeStreamWithFilterAndProjection<T> watchCollection(String collection) {
+
+			Assert.hasText(collection, "Collection name must not be null nor empty!");
+
+			return new ReactiveChangeStreamSupport<>(template, domainType, returnType, collection, options);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithCollection#watchCollection(java.lang.Class)
+		 */
+		@Override
+		public ChangeStreamWithFilterAndProjection<T> watchCollection(Class<?> entityClass) {
+
+			Assert.notNull(entityClass, "Collection type not be null!");
+
+			return watchCollection(template.getCollectionName(entityClass));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#resumeAt(java.lang.Object)
+		 */
+		@Override
+		public TerminatingChangeStream<T> resumeAt(Object token) {
+
+			return withOptions(builder -> {
+
+				if (token instanceof Instant) {
+					builder.resumeAt((Instant) token);
+				} else if (token instanceof BsonTimestamp) {
+					builder.resumeAt((BsonTimestamp) token);
+				}
+			});
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#resumeAfter(java.lang.Object)
+		 */
+		@Override
+		public TerminatingChangeStream<T> resumeAfter(Object token) {
+
+			Assert.isInstanceOf(BsonValue.class, token, "Token must be a BsonValue");
+
+			return withOptions(builder -> builder.resumeAfter((BsonValue) token));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#startAfter(java.lang.Object)
+		 */
+		@Override
+		public TerminatingChangeStream<T> startAfter(Object token) {
+
+			Assert.isInstanceOf(BsonValue.class, token, "Token must be a BsonValue");
+
+			return withOptions(builder -> builder.startAfter((BsonValue) token));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithOptions#withOptions(java.util.function.Consumer)
+		 */
+		@Override
+		public ReactiveChangeStreamSupport<T> withOptions(Consumer<ChangeStreamOptionsBuilder> optionsConsumer) {
+
+			ChangeStreamOptionsBuilder builder = initOptionsBuilder();
+			optionsConsumer.accept(builder);
+
+			return new ReactiveChangeStreamSupport<>(template, domainType, returnType, collection, builder.build());
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithProjection#as(java.lang.Class)
+		 */
+		@Override
+		public <R> ChangeStreamWithFilterAndProjection<R> as(Class<R> resultType) {
+
+			Assert.notNull(resultType, "ResultType must not be null!");
+
+			return new ReactiveChangeStreamSupport<>(template, domainType, resultType, collection, options);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithFilter#filter(org.springframework.data.mongodb.core.aggregation.Aggregation)
+		 */
+		@Override
+		public ChangeStreamWithFilterAndProjection<T> filter(Aggregation filter) {
+			return withOptions(builder -> builder.filter(filter));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithFilter#filter(org.springframework.data.mongodb.core.query.CriteriaDefinition)
+		 */
+		@Override
+		public ChangeStreamWithFilterAndProjection<T> filter(CriteriaDefinition by) {
+
+			MatchOperation $match = Aggregation.match(by);
+			Aggregation aggregation = !Document.class.equals(domainType) ? Aggregation.newAggregation(domainType, $match)
+					: Aggregation.newAggregation($match);
+			return filter(aggregation);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.TerminatingChangeStream#listen()
+		 */
+		@Override
+		public Flux<ChangeStreamEvent<T>> listen() {
+			return template.changeStream(collection, options != null ? options : ChangeStreamOptions.empty(), returnType);
+		}
+
+		private ChangeStreamOptionsBuilder initOptionsBuilder() {
+
+			ChangeStreamOptionsBuilder builder = ChangeStreamOptions.builder();
+			if (options == null) {
+				return builder;
+			}
+
+			options.getFilter().ifPresent(it -> {
+				if (it instanceof Aggregation) {
+					builder.filter((Aggregation) it);
+				} else {
+					builder.filter(((List<Document>) it).toArray(new Document[0]));
+				}
+			});
+			options.getFullDocumentLookup().ifPresent(builder::fullDocumentLookup);
+			options.getCollation().ifPresent(builder::collation);
+
+			if (options.isResumeAfter()) {
+				options.getResumeToken().ifPresent(builder::resumeAfter);
+				options.getResumeBsonTimestamp().ifPresent(builder::resumeAfter);
+			} else if (options.isStartAfter()) {
+				options.getResumeToken().ifPresent(builder::startAfter);
+			} else {
+				options.getResumeTimestamp().ifPresent(builder::resumeAt);
+				options.getResumeBsonTimestamp().ifPresent(builder::resumeAt);
+			}
+
+			return builder;
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveFindOperationSupport.java

@@ -23,6 +23,7 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 import org.bson.Document;
+
 import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
@@ -31,8 +32,6 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
-import com.mongodb.reactivestreams.client.FindPublisher;
-
 /**
  * Implementation of {@link ReactiveFindOperation}.
  *
@@ -120,12 +119,7 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 		public Mono<T> first() {
 
 			FindPublisherPreparer preparer = getCursorPreparer(query);
-			Flux<T> result = doFind(new FindPublisherPreparer() {
-				@Override
-				public <D> FindPublisher<D> prepare(FindPublisher<D> publisher) {
-					return preparer.prepare(publisher).limit(1);
-				}
-			});
+			Flux<T> result = doFind(publisher -> preparer.prepare(publisher).limit(1));
 
 			return result.next();
 		}
@@ -138,12 +132,7 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 		public Mono<T> one() {
 
 			FindPublisherPreparer preparer = getCursorPreparer(query);
-			Flux<T> result = doFind(new FindPublisherPreparer() {
-				@Override
-				public <D> FindPublisher<D> prepare(FindPublisher<D> publisher) {
-					return preparer.prepare(publisher).limit(2);
-				}
-			});
+			Flux<T> result = doFind(publisher -> preparer.prepare(publisher).limit(2));
 
 			return result.collectList().flatMap(it -> {
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveFluentMongoOperations.java

@@ -23,4 +23,4 @@ package org.springframework.data.mongodb.core;
  * @since 2.0
  */
 public interface ReactiveFluentMongoOperations extends ReactiveFindOperation, ReactiveInsertOperation,
-		ReactiveUpdateOperation, ReactiveRemoveOperation, ReactiveAggregationOperation, ReactiveMapReduceOperation {}
+		ReactiveUpdateOperation, ReactiveRemoveOperation, ReactiveAggregationOperation, ReactiveMapReduceOperation, ReactiveChangeStreamOperation {}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java

@@ -29,6 +29,7 @@ import org.springframework.data.geo.GeoResult;
 import org.springframework.data.mongodb.ReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
+import org.springframework.data.mongodb.core.aggregation.AggregationUpdate;
 import org.springframework.data.mongodb.core.aggregation.TypedAggregation;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
@@ -39,7 +40,9 @@ import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import org.springframework.lang.Nullable;
+import org.springframework.transaction.reactive.TransactionalOperator;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -220,7 +223,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * {@link ClientSession#abortTransaction() rolled back} upon errors.
 	 *
 	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 * @deprecated since 2.2. Use {@code @Transactional} or {@link TransactionalOperator}.
 	 */
+	@Deprecated
 	ReactiveSessionScoped inTransaction();
 
 	/**
@@ -235,7 +240,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * @param sessionProvider must not be {@literal null}.
 	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
 	 * @since 2.1
+	 * @deprecated since 2.2. Use {@code @Transactional} or {@link TransactionalOperator}.
 	 */
+	@Deprecated
 	ReactiveSessionScoped inTransaction(Publisher<ClientSession> sessionProvider);
 
 	/**
@@ -619,24 +626,52 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * entity mapping information to determine the collection the query is ran against. Note, that MongoDB limits the
 	 * number of results by default. Make sure to add an explicit limit to the {@link NearQuery} if you expect a
 	 * particular number of results.
+	 * <p>
+	 * MongoDB 4.2 has removed the {@code geoNear} command. This method uses since version 2.2 aggregations and the
+	 * {@code $geoNear} aggregation command to emulate {@code geoNear} command functionality. We recommend using
+	 * aggregations directly:
+	 * </p>
+	 *
+	 * <pre class="code">
+	 * TypedAggregation&lt;T&gt; geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, "dis"))
+	 * 		.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
+	 * Flux&lt;Document&gt; results = aggregate(geoNear, Document.class);
+	 * </pre>
 	 *
 	 * @param near must not be {@literal null}.
 	 * @param entityClass must not be {@literal null}.
 	 * @return the converted {@link GeoResult}s.
+	 * @deprecated since 2.2. The {@code eval} command has been removed in MongoDB Server 4.2.0. Use Aggregations with
+	 *             {@link Aggregation#geoNear(NearQuery, String)} instead.
 	 */
+	@Deprecated
 	<T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<T> entityClass);
 
 	/**
 	 * Returns {@link Flux} of {@link GeoResult} for all entities matching the given {@link NearQuery}. Note, that MongoDB
 	 * limits the number of results by default. Make sure to add an explicit limit to the {@link NearQuery} if you expect
 	 * a particular number of results.
+	 * <p>
+	 * MongoDB 4.2 has removed the {@code geoNear} command. This method uses since version 2.2 aggregations and the
+	 * {@code $geoNear} aggregation command to emulate {@code geoNear} command functionality. We recommend using
+	 * aggregations directly:
+	 * </p>
+	 *
+	 * <pre class="code">
+	 * TypedAggregation&lt;T&gt; geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, "dis"))
+	 * 		.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
+	 * Flux&lt;Document&gt; results = aggregate(geoNear, Document.class);
+	 * </pre>
 	 *
 	 * @param near must not be {@literal null}.
 	 * @param entityClass must not be {@literal null}.
 	 * @param collectionName the collection to trigger the query against. If no collection name is given the entity class
 	 *          will be inspected.
 	 * @return the converted {@link GeoResult}s.
+	 * @deprecated since 2.2. The {@code eval} command has been removed in MongoDB Server 4.2.0. Use Aggregations with
+	 *             {@link Aggregation#geoNear(NearQuery, String)} instead.
 	 */
+	@Deprecated
 	<T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<T> entityClass, String collectionName);
 
 	/**
@@ -645,11 +680,14 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @return the converted object that was updated before it was updated.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	<T> Mono<T> findAndModify(Query query, Update update, Class<T> entityClass);
+	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, Class<T> entityClass);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
@@ -657,12 +695,15 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
 	 * @return the converted object that was updated before it was updated.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	<T> Mono<T> findAndModify(Query query, Update update, Class<T> entityClass, String collectionName);
+	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, Class<T> entityClass, String collectionName);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
@@ -671,13 +712,16 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification.
-	 * @param update the {@link Update} to apply on matching documents.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents.
 	 * @param options the {@link FindAndModifyOptions} holding additional information.
 	 * @param entityClass the parametrized type.
 	 * @return the converted object that was updated. Depending on the value of {@link FindAndModifyOptions#isReturnNew()}
 	 *         this will either be the object as it was before the update or as it is after the update.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	<T> Mono<T> findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass);
+	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
 	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
@@ -686,14 +730,17 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
-	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} to apply on matching documents. Must not be {@literal null}.
 	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
 	 * @return the converted object that was updated. Depending on the value of {@link FindAndModifyOptions#isReturnNew()}
 	 *         this will either be the object as it was before the update or as it is after the update.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	<T> Mono<T> findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
+	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass,
 			String collectionName);
 
 	/**
@@ -887,6 +934,11 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the collection of the given entity class.
+	 * <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -898,7 +950,11 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Returns the number of documents for the given {@link Query} querying the given collection. The given {@link Query}
 	 * must solely consist of document field references as we lack type information to map potential property references
-	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support.
+	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support. <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
@@ -909,7 +965,11 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the given collection using the given entity
-	 * class to map the given {@link Query}.
+	 * class to map the given {@link Query}. <br />
+	 * <strong>NOTE:</strong> Query {@link Query#getSkip() offset} and {@link Query#getLimit() limit} can have direct
+	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
+	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
+	 * count all matches.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -927,8 +987,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 * <p/>
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
@@ -987,8 +1047,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 * <p/>
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
@@ -1035,8 +1095,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
@@ -1072,8 +1132,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
-	 * Conversion"</a> for more details.
+	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
+	 * Type Conversion"</a> for more details.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
@@ -1103,99 +1163,111 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document. <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class)} instead.
+	 * Use {@link #findAndModify(Query, UpdateDefinition, Class)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> upsert(Query query, Update update, Class<?> entityClass);
+	Mono<UpdateResult> upsert(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #upsert(Query, Update, Class, String)} to get full type specific support.
-	 * <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
+	 * domain type information. Use {@link #upsert(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> upsert(Query query, Update update, String collectionName);
+	Mono<UpdateResult> upsert(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
-	 * combining the query document and the update document. <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
+	 * combining the query document and the update document.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing object. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> upsert(Query query, Update update, Class<?> entityClass, String collectionName);
+	Mono<UpdateResult> upsert(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the collection of the entity class that matches the query document with
 	 * the provided update document. <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class)} instead.
+	 * Use {@link #findAndModify(Query, UpdateDefinition, Class)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateFirst(Query query, Update update, Class<?> entityClass);
+	Mono<UpdateResult> updateFirst(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
 	 * the provided updated document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #updateFirst(Query, Update, Class, String)} to get full type specific support.
-	 * <br />
+	 * domain type information. Use {@link #updateFirst(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support. <br />
 	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
 	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateFirst(Query query, Update update, String collectionName);
+	Mono<UpdateResult> updateFirst(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
 	 * the provided updated document. <br />
-	 * <strong>NOTE:</strong> {@link Query#getSortObject() sorting} is not supported by {@code db.collection.updateOne}.
-	 * Use {@link #findAndModify(Query, Update, Class, String)} instead.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateFirst(Query query, Update update, Class<?> entityClass, String collectionName);
+	Mono<UpdateResult> updateFirst(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
@@ -1203,27 +1275,34 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateMulti(Query query, Update update, Class<?> entityClass);
+	Mono<UpdateResult> updateMulti(Query query, UpdateDefinition update, Class<?> entityClass);
 
 	/**
 	 * Updates all objects that are found in the specified collection that matches the query document criteria with the
 	 * provided updated document. <br />
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #updateMulti(Query, Update, Class, String)} to get full type specific support.
+	 * domain type information. Use {@link #updateMulti(Query, UpdateDefinition, Class, String)} to get full type specific
+	 * support.
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateMulti(Query query, Update update, String collectionName);
+	Mono<UpdateResult> updateMulti(Query query, UpdateDefinition update, String collectionName);
 
 	/**
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
@@ -1231,13 +1310,16 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
-	 *          not be {@literal null}.
+	 * @param update the {@link UpdateDefinition} that contains the updated object or {@code $} operators to manipulate
+	 *          the existing. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
 	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
+	 * @since 3.0
+	 * @see Update
+	 * @see AggregationUpdate
 	 */
-	Mono<UpdateResult> updateMulti(Query query, Update update, Class<?> entityClass, String collectionName);
+	Mono<UpdateResult> updateMulti(Query query, UpdateDefinition update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Remove the given object from the collection by id.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveUpdateOperation.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mongodb.core;
 
+import org.springframework.data.mongodb.core.aggregation.AggregationUpdate;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import reactor.core.publisher.Mono;
 
 import org.springframework.data.mongodb.core.query.Query;
@@ -118,13 +120,16 @@ public interface ReactiveUpdateOperation {
 	interface UpdateWithUpdate<T> {
 
 		/**
-		 * Set the {@link org.springframework.data.mongodb.core.query.Update} to be applied.
+		 * Set the {@link UpdateDefinition} to be applied.
 		 *
 		 * @param update must not be {@literal null}.
 		 * @return new instance of {@link TerminatingUpdate}. Never {@literal null}.
 		 * @throws IllegalArgumentException if update is {@literal null}.
+		 * @since 3.0
+		 * @see Update
+		 * @see AggregationUpdate
 		 */
-		TerminatingUpdate<T> apply(org.springframework.data.mongodb.core.query.Update update);
+		TerminatingUpdate<T> apply(UpdateDefinition update);
 
 		/**
 		 * Specify {@code replacement} object.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveUpdateOperationSupport.java

@@ -63,7 +63,7 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 		@NonNull ReactiveMongoTemplate template;
 		@NonNull Class<?> domainType;
 		Query query;
-		org.springframework.data.mongodb.core.query.Update update;
+		org.springframework.data.mongodb.core.query.UpdateDefinition update;
 		@Nullable String collection;
 		@Nullable FindAndModifyOptions findAndModifyOptions;
 		@Nullable FindAndReplaceOptions findAndReplaceOptions;
@@ -72,10 +72,10 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 
 		/*
 		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithUpdate#apply(org.springframework.data.mongodb.core.query.Update)
+		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithUpdate#apply(org.springframework.data.mongodb.core.query.UpdateDefinition)
 		 */
 		@Override
-		public TerminatingUpdate<T> apply(org.springframework.data.mongodb.core.query.Update update) {
+		public TerminatingUpdate<T> apply(org.springframework.data.mongodb.core.query.UpdateDefinition update) {
 
 			Assert.notNull(update, "Update must not be null!");
 
@@ -123,7 +123,7 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 
 			String collectionName = getCollectionName();
 
-			return template.findAndModify(query, update, findAndModifyOptions, targetType, collectionName);
+			return template.findAndModify(query, update, findAndModifyOptions != null ? findAndModifyOptions : FindAndModifyOptions.none(), targetType, collectionName);
 		}
 
 		/*
@@ -133,7 +133,7 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 		@Override
 		public Mono<T> findAndReplace() {
 			return template.findAndReplace(query, replacement,
-					findAndReplaceOptions != null ? findAndReplaceOptions : new FindAndReplaceOptions(), (Class) domainType,
+					findAndReplaceOptions != null ? findAndReplaceOptions : FindAndReplaceOptions.none(), (Class) domainType,
 					getCollectionName(), targetType);
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReadPreferenceAware.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import org.springframework.lang.Nullable;
+
+import com.mongodb.ReadPreference;
+
+/**
+ * Interface to be implemented by any object that wishes to expose the {@link ReadPreference}.
+ * <p>
+ * Typically implemented by cursor or query preparer objects.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.2
+ */
+public interface ReadPreferenceAware {
+
+	/**
+	 * @return {@literal true} if a {@link ReadPreference} is set.
+	 */
+	default boolean hasReadPreference() {
+		return getReadPreference() != null;
+	}
+
+	/**
+	 * @return the {@link ReadPreference} to apply or {@literal null} if none set.
+	 */
+	@Nullable
+	ReadPreference getReadPreference();
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ScriptOperations.java

@@ -29,7 +29,9 @@ import com.mongodb.DB;
  * @author Christoph Strobl
  * @author Oliver Gierke
  * @since 1.7
+ * @deprecated since 2.2. The {@code eval} command has been removed without replacement in MongoDB Server 4.2.0.
  */
+@Deprecated
 public interface ScriptOperations {
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/SimpleMongoDbFactory.java

@@ -21,9 +21,7 @@ import com.mongodb.ClientSessionOptions;
 import com.mongodb.DB;
 import com.mongodb.MongoClient;
 import com.mongodb.MongoClientURI;
-import com.mongodb.WriteConcern;
 import com.mongodb.client.ClientSession;
-import com.mongodb.client.MongoCollection;
 import com.mongodb.client.MongoDatabase;
 
 /**
@@ -35,7 +33,9 @@ import com.mongodb.client.MongoDatabase;
  * @author Christoph Strobl
  * @author George Moraitis
  * @author Mark Paluch
+ * @deprecated since 2.2 in favor of {@link SimpleMongoClientDbFactory}.
  */
+@Deprecated
 public class SimpleMongoDbFactory extends MongoDbFactorySupport<MongoClient> implements DisposableBean {
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/SimpleReactiveMongoDatabaseFactory.java

@@ -211,6 +211,15 @@ public class SimpleReactiveMongoDatabaseFactory implements DisposableBean, React
 			return delegate.withSession(session);
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.ReactiveMongoDatabaseFactory#isTransactionActive()
+		 */
+		@Override
+		public boolean isTransactionActive() {
+			return session != null && session.hasActiveTransaction();
+		}
+
 		private MongoDatabase decorateDatabase(MongoDatabase database) {
 			return createProxyInstance(session, database, MongoDatabase.class);
 		}
@@ -233,7 +242,7 @@ public class SimpleReactiveMongoDatabaseFactory implements DisposableBean, React
 			factory.addAdvice(new SessionAwareMethodInterceptor<>(session, target, ClientSession.class, MongoDatabase.class,
 					this::proxyDatabase, MongoCollection.class, this::proxyCollection));
 
-			return targetType.cast(factory.getProxy(target.getClass().getClassLoader()));
+			return targetType.cast(factory.getProxy());
 		}
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AccumulatorOperators.java

@@ -213,6 +213,20 @@ public class AccumulatorOperators {
 			return new Sum(append(expression));
 		}
 
+		/**
+		 * Creates new {@link Sum} with all previously added arguments appending the given one. <br />
+		 * <strong>NOTE:</strong> Only possible in {@code $project} stage.
+		 *
+		 * @param value the value to add.
+		 * @return new instance of {@link Sum}.
+		 * @since 2.2
+		 */
+		public Sum and(Number value) {
+
+			Assert.notNull(value, "Value must not be null!");
+			return new Sum(append(value));
+		}
+
 		/* (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.aggregation.AccumulatorOperators.AbstractAggregationExpression#toDocument(java.lang.Object, org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
 		 */

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Aggregation.java

@@ -115,6 +115,17 @@ public class Aggregation {
 		return new Aggregation(operations);
 	}
 
+	/**
+	 * Creates a new {@link AggregationUpdate} from the given {@link AggregationOperation}s.
+	 * 
+	 * @param operations can be {@literal empty} but must not be {@literal null}.
+	 * @return new instance of {@link AggregationUpdate}.
+	 * @since 3.0
+	 */
+	public static AggregationUpdate newUpdate(AggregationOperation... operations) {
+		return AggregationUpdate.from(Arrays.asList(operations));
+	}
+
 	/**
 	 * Returns a copy of this {@link Aggregation} with the given {@link AggregationOptions} set. Note that options are
 	 * supported in MongoDB version 2.6+.
@@ -181,13 +192,12 @@ public class Aggregation {
 	/**
 	 * Creates a new {@link Aggregation} from the given {@link AggregationOperation}s.
 	 *
-	 * @param aggregationOperations must not be {@literal null} or empty.
+	 * @param aggregationOperations must not be {@literal null}.
 	 * @param options must not be {@literal null} or empty.
 	 */
 	protected Aggregation(List<AggregationOperation> aggregationOperations, AggregationOptions options) {
 
 		Assert.notNull(aggregationOperations, "AggregationOperations must not be null!");
-		Assert.isTrue(!aggregationOperations.isEmpty(), "At least one AggregationOperation has to be provided");
 		Assert.notNull(options, "AggregationOptions must not be null!");
 
 		// check $out is the last operation if it exists
@@ -244,6 +254,19 @@ public class Aggregation {
 		return new ProjectionOperation(fields);
 	}
 
+	/**
+	 * Creates a new {@link ProjectionOperation} including all top level fields of the given given {@link Class}.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return new instance of {@link ProjectionOperation}.
+	 * @since 2.2
+	 */
+	public static ProjectionOperation project(Class<?> type) {
+
+		Assert.notNull(type, "Type must not be null!");
+		return new ProjectionOperation(type);
+	}
+
 	/**
 	 * Factory method to create a new {@link UnwindOperation} for the field with the given name.
 	 *
@@ -612,7 +635,7 @@ public class Aggregation {
 	}
 
 	/**
-	 * Creates a new {@link GeoNearOperation} instance from the given {@link NearQuery} and the{@code distanceField}. The
+	 * Creates a new {@link GeoNearOperation} instance from the given {@link NearQuery} and the {@code distanceField}. The
 	 * {@code distanceField} defines output field that contains the calculated distance.
 	 *
 	 * @param query must not be {@literal null}.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationOperation.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.data.mongodb.core.aggregation;
 
+import java.util.Collections;
+import java.util.List;
+
 import org.bson.Document;
 
 /**
@@ -32,7 +35,23 @@ public interface AggregationOperation {
 	 * Turns the {@link AggregationOperation} into a {@link Document} by using the given
 	 * {@link AggregationOperationContext}.
 	 *
+	 * @param context the {@link AggregationOperationContext} to operate within. Must not be {@literal null}.
 	 * @return the Document
+	 * @deprecated since 2.2 in favor of {@link #toPipelineStages(AggregationOperationContext)}.
 	 */
+	@Deprecated
 	Document toDocument(AggregationOperationContext context);
+
+	/**
+	 * Turns the {@link AggregationOperation} into list of {@link Document stages} by using the given
+	 * {@link AggregationOperationContext}. This allows a single {@link AggregationOptions} to add additional stages for
+	 * eg. {@code $sort} or {@code $limit}.
+	 *
+	 * @param context the {@link AggregationOperationContext} to operate within. Must not be {@literal null}.
+	 * @return the pipeline stages to run through. Never {@literal null}.
+	 * @since 2.2
+	 */
+	default List<Document> toPipelineStages(AggregationOperationContext context) {
+		return Collections.singletonList(toDocument(context));
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationOperationContext.java

@@ -15,8 +15,17 @@
  */
 package org.springframework.data.mongodb.core.aggregation;
 
+import java.beans.PropertyDescriptor;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+
 import org.bson.Document;
+
+import org.springframework.beans.BeanUtils;
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * The context for an {@link AggregationOperation}.
@@ -33,7 +42,20 @@ public interface AggregationOperationContext {
 	 * @param document will never be {@literal null}.
 	 * @return must not be {@literal null}.
 	 */
-	Document getMappedObject(Document document);
+	default Document getMappedObject(Document document) {
+		return getMappedObject(document, null);
+	}
+
+	/**
+	 * Returns the mapped {@link Document}, potentially converting the source considering mapping metadata for the given
+	 * type.
+	 *
+	 * @param document will never be {@literal null}.
+	 * @param type can be {@literal null}.
+	 * @return must not be {@literal null}.
+	 * @since 2.2
+	 */
+	Document getMappedObject(Document document, @Nullable Class<?> type);
 
 	/**
 	 * Returns a {@link FieldReference} for the given field or {@literal null} if the context does not expose the given
@@ -52,4 +74,33 @@ public interface AggregationOperationContext {
 	 * @return
 	 */
 	FieldReference getReference(String name);
+
+	/**
+	 * Returns the {@link Fields} exposed by the type. May be a {@literal class} or an {@literal interface}. The default
+	 * implementation uses {@link BeanUtils#getPropertyDescriptors(Class) property descriptors} discover fields from a
+	 * {@link Class}.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.2
+	 * @see BeanUtils#getPropertyDescriptor(Class, String)
+	 */
+	default Fields getFields(Class<?> type) {
+
+		Assert.notNull(type, "Type must not be null!");
+
+		return Fields.fields(Arrays.stream(BeanUtils.getPropertyDescriptors(type)) //
+				.filter(it -> { // object and default methods
+					Method method = it.getReadMethod();
+					if (method == null) {
+						return false;
+					}
+					if (ReflectionUtils.isObjectMethod(method)) {
+						return false;
+					}
+					return !method.isDefault();
+				}) //
+				.map(PropertyDescriptor::getName) //
+				.toArray(String[]::new));
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationOperationRenderer.java

@@ -24,6 +24,7 @@ import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedFi
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
 import org.springframework.data.mongodb.core.aggregation.Fields.AggregationField;
 import org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation;
+import org.springframework.lang.Nullable;
 
 /**
  * Rendering support for {@link AggregationOperation} into a {@link List} of {@link org.bson.Document}.
@@ -52,7 +53,7 @@ class AggregationOperationRenderer {
 
 		for (AggregationOperation operation : operations) {
 
-			operationDocuments.add(operation.toDocument(contextToUse));
+			operationDocuments.addAll(operation.toPipelineStages(contextToUse));
 
 			if (operation instanceof FieldsExposingAggregationOperation) {
 
@@ -75,15 +76,16 @@ class AggregationOperationRenderer {
 	 * Simple {@link AggregationOperationContext} that just returns {@link FieldReference}s as is.
 	 *
 	 * @author Oliver Gierke
+	 * @author Christoph Strobl
 	 */
 	private static class NoOpAggregationOperationContext implements AggregationOperationContext {
 
 		/*
 		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document)
+		 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document, java.lang.Class)
 		 */
 		@Override
-		public Document getMappedObject(Document document) {
+		public Document getMappedObject(Document document, @Nullable Class<?> type) {
 			return document;
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationOptions.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.mongodb.core.aggregation;
 
+import java.time.Duration;
 import java.util.Optional;
 
 import org.bson.Document;
@@ -44,11 +45,15 @@ public class AggregationOptions {
 	private static final String EXPLAIN = "explain";
 	private static final String ALLOW_DISK_USE = "allowDiskUse";
 	private static final String COLLATION = "collation";
+	private static final String COMMENT = "comment";
+	private static final String MAX_TIME = "maxTimeMS";
 
 	private final boolean allowDiskUse;
 	private final boolean explain;
 	private final Optional<Document> cursor;
 	private final Optional<Collation> collation;
+	private final Optional<String> comment;
+	private Duration maxTime = Duration.ZERO;
 
 	/**
 	 * Creates a new {@link AggregationOptions}.
@@ -73,11 +78,28 @@ public class AggregationOptions {
 	 */
 	public AggregationOptions(boolean allowDiskUse, boolean explain, @Nullable Document cursor,
 			@Nullable Collation collation) {
+		this(allowDiskUse, explain, cursor, collation, null);
+	}
+
+	/**
+	 * Creates a new {@link AggregationOptions}.
+	 *
+	 * @param allowDiskUse whether to off-load intensive sort-operations to disk.
+	 * @param explain whether to get the execution plan for the aggregation instead of the actual results.
+	 * @param cursor can be {@literal null}, used to pass additional options (such as {@code batchSize}) to the
+	 *          aggregation.
+	 * @param collation collation for string comparison. Can be {@literal null}.
+	 * @param comment execution comment. Can be {@literal null}.
+	 * @since 2.2
+	 */
+	public AggregationOptions(boolean allowDiskUse, boolean explain, @Nullable Document cursor,
+			@Nullable Collation collation, @Nullable String comment) {
 
 		this.allowDiskUse = allowDiskUse;
 		this.explain = explain;
 		this.cursor = Optional.ofNullable(cursor);
 		this.collation = Optional.ofNullable(collation);
+		this.comment = Optional.ofNullable(comment);
 	}
 
 	/**
@@ -108,8 +130,13 @@ public class AggregationOptions {
 		Document cursor = document.get(CURSOR, Document.class);
 		Collation collation = document.containsKey(COLLATION) ? Collation.from(document.get(COLLATION, Document.class))
 				: null;
+		String comment = document.getString(COMMENT);
 
-		return new AggregationOptions(allowDiskUse, explain, cursor, collation);
+		AggregationOptions options = new AggregationOptions(allowDiskUse, explain, cursor, collation, comment);
+		if (document.containsKey(MAX_TIME)) {
+			options.maxTime = Duration.ofMillis(document.getLong(MAX_TIME));
+		}
+		return options;
 	}
 
 	/**
@@ -176,6 +203,24 @@ public class AggregationOptions {
 		return collation;
 	}
 
+	/**
+	 * Get the comment for the aggregation.
+	 *
+	 * @return
+	 * @since 2.2
+	 */
+	public Optional<String> getComment() {
+		return comment;
+	}
+
+	/**
+	 * @return the time limit for processing. {@link Duration#ZERO} is used for the default unbounded behavior.
+	 * @since 3.0
+	 */
+	public Duration getMaxTime() {
+		return maxTime;
+	}
+
 	/**
 	 * Returns a new potentially adjusted copy for the given {@code aggregationCommandObject} with the configuration
 	 * applied.
@@ -203,6 +248,10 @@ public class AggregationOptions {
 			collation.map(Collation::toDocument).ifPresent(val -> result.append(COLLATION, val));
 		}
 
+		if (hasExecutionTimeLimit() && !result.containsKey(MAX_TIME)) {
+			result.append(MAX_TIME, maxTime.toMillis());
+		}
+
 		return result;
 	}
 
@@ -219,10 +268,23 @@ public class AggregationOptions {
 
 		cursor.ifPresent(val -> document.put(CURSOR, val));
 		collation.ifPresent(val -> document.append(COLLATION, val.toDocument()));
+		comment.ifPresent(val -> document.append(COMMENT, val));
+
+		if (hasExecutionTimeLimit()) {
+			document.append(MAX_TIME, maxTime.toMillis());
+		}
 
 		return document;
 	}
 
+	/**
+	 * @return
+	 * @since 3.0
+	 */
+	public boolean hasExecutionTimeLimit() {
+		return !maxTime.isZero() && !maxTime.isNegative();
+	}
+
 	/* (non-Javadoc)
 	 * @see java.lang.Object#toString()
 	 */
@@ -247,6 +309,8 @@ public class AggregationOptions {
 		private boolean explain;
 		private @Nullable Document cursor;
 		private @Nullable Collation collation;
+		private @Nullable String comment;
+		private @Nullable Duration maxTime;
 
 		/**
 		 * Defines whether to off-load intensive sort-operations to disk.
@@ -302,6 +366,7 @@ public class AggregationOptions {
 		 *
 		 * @param collation can be {@literal null}.
 		 * @return
+		 * @since 2.0
 		 */
 		public Builder collation(@Nullable Collation collation) {
 
@@ -309,13 +374,46 @@ public class AggregationOptions {
 			return this;
 		}
 
+		/**
+		 * Define a comment to describe the execution.
+		 *
+		 * @param comment can be {@literal null}.
+		 * @return
+		 * @since 2.2
+		 */
+		public Builder comment(@Nullable String comment) {
+
+			this.comment = comment;
+			return this;
+		}
+
+		/**
+		 * Set the time limit for processing.
+		 *
+		 * @param maxTime {@link Duration#ZERO} is used for the default unbounded behavior. {@link Duration#isNegative()
+		 *          Negative} values will be ignored.
+		 * @return this.
+		 * @since 3.0
+		 */
+		public Builder maxTime(@Nullable Duration maxTime) {
+
+			this.maxTime = maxTime;
+			return this;
+		}
+
 		/**
 		 * Returns a new {@link AggregationOptions} instance with the given configuration.
 		 *
 		 * @return
 		 */
 		public AggregationOptions build() {
-			return new AggregationOptions(allowDiskUse, explain, cursor, collation);
+
+			AggregationOptions options = new AggregationOptions(allowDiskUse, explain, cursor, collation, comment);
+			if (maxTime != null) {
+				options.maxTime = maxTime;
+			}
+
+			return options;
 		}
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationUpdate.java

@@ -0,0 +1,325 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.aggregation;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.StringJoiner;
+import java.util.stream.Collectors;
+
+import org.bson.Document;
+
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.data.mongodb.core.query.SerializationUtils;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+/**
+ * Abstraction for {@code db.collection.update()} using an aggregation pipeline. Aggregation pipeline updates use a more
+ * expressive update statement expressing conditional updates based on current field values or updating one field using
+ * the value of another field(s).
+ *
+ * <pre class="code">
+ * AggregationUpdate update = AggregationUpdate.update().set("average")
+ * 		.toValue(ArithmeticOperators.valueOf("tests").avg()).set("grade")
+ * 		.toValue(ConditionalOperators
+ * 				.switchCases(CaseOperator.when(Gte.valueOf("average").greaterThanEqualToValue(90)).then("A"),
+ * 						CaseOperator.when(Gte.valueOf("average").greaterThanEqualToValue(80)).then("B"),
+ * 						CaseOperator.when(Gte.valueOf("average").greaterThanEqualToValue(70)).then("C"),
+ * 						CaseOperator.when(Gte.valueOf("average").greaterThanEqualToValue(60)).then("D"))
+ * 				.defaultTo("F"));
+ * </pre>
+ *
+ * The above sample is equivalent to the JSON update statement:
+ *
+ * <pre class="code">
+ * db.collection.update(
+ *    { },
+ *    [
+ *      { $set: { average : { $avg: "$tests" } } },
+ *      { $set: { grade: { $switch: {
+ *                            branches: [
+ *                                { case: { $gte: [ "$average", 90 ] }, then: "A" },
+ *                                { case: { $gte: [ "$average", 80 ] }, then: "B" },
+ *                                { case: { $gte: [ "$average", 70 ] }, then: "C" },
+ *                                { case: { $gte: [ "$average", 60 ] }, then: "D" }
+ *                            ],
+ *                            default: "F"
+ *      } } } }
+ *    ],
+ *    { multi: true }
+ * )
+ * </pre>
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @see <a href=
+ *      "https://docs.mongodb.com/manual/reference/method/db.collection.update/#update-with-aggregation-pipeline">MongoDB
+ *      Reference Documentation</a>
+ * @since 3.0
+ */
+public class AggregationUpdate extends Aggregation implements UpdateDefinition {
+
+	private boolean isolated = false;
+	private Set<String> keysTouched = new HashSet<>();
+
+	/**
+	 * Create new {@link AggregationUpdate}.
+	 */
+	protected AggregationUpdate() {
+		this(new ArrayList<>());
+	}
+
+	/**
+	 * Create new {@link AggregationUpdate} with the given aggregation pipeline to apply.
+	 *
+	 * @param pipeline must not be {@literal null}.
+	 */
+	protected AggregationUpdate(List<AggregationOperation> pipeline) {
+
+		super(pipeline);
+
+		for (AggregationOperation operation : pipeline) {
+			if (operation instanceof FieldsExposingAggregationOperation) {
+				((FieldsExposingAggregationOperation) operation).getFields().forEach(it -> {
+					keysTouched.add(it.getName());
+				});
+			}
+		}
+	}
+
+	/**
+	 * Start defining the update pipeline to execute.
+	 *
+	 * @return new instance of {@link AggregationUpdate}.
+	 */
+	public static AggregationUpdate update() {
+		return new AggregationUpdate();
+	}
+
+	/**
+	 * Create a new AggregationUpdate from the given {@link AggregationOperation}s.
+	 *
+	 * @return new instance of {@link AggregationUpdate}.
+	 */
+	public static AggregationUpdate from(List<AggregationOperation> pipeline) {
+		return new AggregationUpdate(pipeline);
+	}
+
+	/**
+	 * Adds new fields to documents. {@code $set} outputs documents that contain all existing fields from the input
+	 * documents and newly added fields.
+	 *
+	 * @param setOperation must not be {@literal null}.
+	 * @return this.
+	 * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/set/">$set Aggregation Reference</a>
+	 */
+	public AggregationUpdate set(SetOperation setOperation) {
+
+		Assert.notNull(setOperation, "SetOperation must not be null!");
+
+		setOperation.getFields().forEach(it -> {
+			keysTouched.add(it.getName());
+		});
+		operations.add(setOperation);
+		return this;
+	}
+
+	/**
+	 * {@code $unset} removes/excludes fields from documents.
+	 *
+	 * @param unsetOperation must not be {@literal null}.
+	 * @return this.
+	 * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/unset/">$unset Aggregation
+	 *      Reference</a>
+	 */
+	public AggregationUpdate unset(UnsetOperation unsetOperation) {
+
+		Assert.notNull(unsetOperation, "UnsetOperation must not be null!");
+
+		operations.add(unsetOperation);
+		keysTouched.addAll(unsetOperation.removedFieldNames());
+		return this;
+	}
+
+	/**
+	 * {@code $replaceWith} replaces the input document with the specified document. The operation replaces all existing
+	 * fields in the input document, including the <strong>_id</strong> field.
+	 *
+	 * @param replaceWithOperation
+	 * @return this.
+	 * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/replaceWith/">$replaceWith Aggregation
+	 *      Reference</a>
+	 */
+	public AggregationUpdate replaceWith(ReplaceWithOperation replaceWithOperation) {
+
+		Assert.notNull(replaceWithOperation, "ReplaceWithOperation must not be null!");
+		operations.add(replaceWithOperation);
+		return this;
+	}
+
+	/**
+	 * {@code $replaceWith} replaces the input document with the value.
+	 *
+	 * @param value must not be {@literal null}.
+	 * @return this.
+	 */
+	public AggregationUpdate replaceWith(Object value) {
+
+		Assert.notNull(value, "Value must not be null!");
+		return replaceWith(ReplaceWithOperation.replaceWithValue(value));
+	}
+
+	/**
+	 * Fluent API variant for {@code $set} adding a single {@link SetOperation pipeline operation} every time. To update
+	 * multiple fields within one {@link SetOperation} use {@link #set(SetOperation)}.
+	 *
+	 * @param key must not be {@literal null}.
+	 * @return new instance of {@link SetValueAppender}.
+	 * @see #set(SetOperation)
+	 */
+	public SetValueAppender set(String key) {
+
+		Assert.notNull(key, "Key must not be null!");
+
+		return new SetValueAppender() {
+
+			@Override
+			public AggregationUpdate toValue(@Nullable Object value) {
+				return set(SetOperation.builder().set(key).toValue(value));
+			}
+
+			@Override
+			public AggregationUpdate toValueOf(Object value) {
+
+				Assert.notNull(value, "Value must not be null!");
+				return set(SetOperation.builder().set(key).toValueOf(value));
+			}
+		};
+	}
+
+	/**
+	 * Short for {@link #unset(UnsetOperation)}.
+	 *
+	 * @param keys
+	 * @return
+	 */
+	public AggregationUpdate unset(String... keys) {
+
+		Assert.notNull(keys, "Keys must not be null!");
+		Assert.noNullElements(keys, "Keys must not contain null elements.");
+
+		return unset(new UnsetOperation(Arrays.stream(keys).map(Fields::field).collect(Collectors.toList())));
+	}
+
+	/**
+	 * Prevents a write operation that affects <strong>multiple</strong> documents from yielding to other reads or writes
+	 * once the first document is written. <br />
+	 * Use with {@link org.springframework.data.mongodb.core.MongoOperations#updateMulti(Query, UpdateDefinition, Class)}.
+	 *
+	 * @return never {@literal null}.
+	 */
+	public AggregationUpdate isolated() {
+
+		isolated = true;
+		return this;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#isIsolated()
+	 */
+	@Override
+	public Boolean isIsolated() {
+		return isolated;
+	}
+
+	/*
+	 * Returns a update document containing the update pipeline.
+	 * The resulting document needs to be unwrapped to be used with update operations.
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#getUpdateObject()
+	 */
+	@Override
+	public Document getUpdateObject() {
+		return new Document("", toPipeline(Aggregation.DEFAULT_CONTEXT));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#modifies(java.lang.String)
+	 */
+	@Override
+	public boolean modifies(String key) {
+		return keysTouched.contains(key);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#inc(java.lang.String)
+	 */
+	@Override
+	public void inc(String key) {
+		set(new SetOperation(key, ArithmeticOperators.valueOf(key).add(1)));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#getArrayFilters()
+	 */
+	@Override
+	public List<ArrayFilter> getArrayFilters() {
+		return Collections.emptyList();
+	}
+
+	@Override
+	public String toString() {
+
+		StringJoiner joiner = new StringJoiner(",\n", "[\n", "\n]");
+		toPipeline(Aggregation.DEFAULT_CONTEXT).stream().map(SerializationUtils::serializeToJsonSafely)
+				.forEach(joiner::add);
+		return joiner.toString();
+	}
+
+	/**
+	 * Fluent API AggregationUpdate builder.
+	 *
+	 * @author Christoph Strobl
+	 */
+	public interface SetValueAppender {
+
+		/**
+		 * Define the target value as is.
+		 *
+		 * @param value can be {@literal null}.
+		 * @return never {@literal null}.
+		 */
+		AggregationUpdate toValue(@Nullable Object value);
+
+		/**
+		 * Define the target value as value, an {@link AggregationExpression} or a {@link Field} reference.
+		 *
+		 * @param value can be {@literal null}.
+		 * @return never {@literal null}.
+		 */
+		AggregationUpdate toValueOf(Object value);
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ArithmeticOperators.java

@@ -511,6 +511,27 @@ public class ArithmeticOperators {
 					: AccumulatorOperators.StdDevSamp.stdDevSampOf(expression);
 		}
 
+		/**
+		 * Creates new {@link AggregationExpression} that rounds a number to a whole integer or to a specified decimal
+		 * place.
+		 *
+		 * @return new instance of {@link Round}.
+		 * @since 3.0
+		 */
+		public Round round() {
+			return usesFieldRef() ? Round.roundValueOf(fieldReference) : Round.roundValueOf(expression);
+		}
+
+		/**
+		 * Creates new {@link AggregationExpression} that rounds a number to a specified decimal place.
+		 *
+		 * @return new instance of {@link Round}.
+		 * @since 3.0
+		 */
+		public Round roundToPlace(int place) {
+			return round().place(place);
+		}
+
 		private boolean usesFieldRef() {
 			return fieldReference != null;
 		}
@@ -1422,4 +1443,100 @@ public class ArithmeticOperators {
 			return new Trunc(value);
 		}
 	}
+
+	/**
+	 * {@link Round} rounds a number to a whole integer or to a specified decimal place.
+	 * <ul>
+	 * <li>If {@link Round#place(int)} resolves to a positive integer, {@code $round} rounds to the given decimal
+	 * places.</li>
+	 * <li>If {@link Round#place(int)} resolves to a negative integer, {@code $round} rounds to the left of the
+	 * decimal.</li>
+	 * <li>If {@link Round#place(int)} resolves to a zero, {@code $round} rounds using the first digit to the right of the
+	 * decimal.</li>
+	 * </ul>
+	 *
+	 * @since 3.0
+	 */
+	public static class Round extends AbstractAggregationExpression {
+
+		private Round(Object value) {
+			super(value);
+		}
+
+		/**
+		 * Round the value of the field that resolves to an integer, double, decimal, or long.
+		 *
+		 * @param fieldReference must not be {@literal null}.
+		 * @return new instance of {@link Round}.
+		 */
+		public static Round roundValueOf(String fieldReference) {
+
+			Assert.notNull(fieldReference, "FieldReference must not be null!");
+			return new Round(Collections.singletonList(Fields.field(fieldReference)));
+		}
+
+		/**
+		 * Round the outcome of the given expression hat resolves to an integer, double, decimal, or long.
+		 *
+		 * @param expression must not be {@literal null}.
+		 * @return new instance of {@link Round}.
+		 */
+		public static Round roundValueOf(AggregationExpression expression) {
+
+			Assert.notNull(expression, "Expression must not be null!");
+			return new Round(Collections.singletonList(expression));
+		}
+
+		/**
+		 * Round the given numeric (integer, double, decimal, or long) value.
+		 *
+		 * @param value must not be {@literal null}.
+		 * @return new instance of {@link Round}.
+		 */
+		public static Round round(Number value) {
+
+			Assert.notNull(value, "Value must not be null!");
+			return new Round(Collections.singletonList(value));
+		}
+
+		/**
+		 * The place to round to. Can be between -20 and 100, exclusive.
+		 *
+		 * @param place
+		 * @return new instance of {@link Round}.
+		 */
+		public Round place(int place) {
+			return new Round(append(place));
+		}
+
+		/**
+		 * The place to round to defined by an expression that resolves to an integer between -20 and 100, exclusive.
+		 *
+		 * @param expression must not be {@literal null}.
+		 * @return new instance of {@link Round}.
+		 */
+		public Round placeOf(AggregationExpression expression) {
+
+			Assert.notNull(expression, "Expression must not be null!");
+			return new Round(append(expression));
+		}
+
+		/**
+		 * The place to round to defined by via a field reference that resolves to an integer between -20 and 100,
+		 * exclusive.
+		 *
+		 * @param fieldReference must not be {@literal null}.
+		 * @return new instance of {@link Round}.
+		 */
+		public Round placeOf(String fieldReference) {
+
+			Assert.notNull(fieldReference, "fieldReference must not be null!");
+			return new Round(append(Fields.field(fieldReference)));
+		}
+
+		@Override
+		protected String getMongoMethod() {
+			return "$round";
+		}
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ArrayOperators.java

@@ -17,6 +17,7 @@ package org.springframework.data.mongodb.core.aggregation;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
@@ -33,6 +34,7 @@ import org.springframework.util.Assert;
  *
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Shashank Sharma
  * @since 1.0
  */
 public class ArrayOperators {
@@ -57,13 +59,25 @@ public class ArrayOperators {
 		return new ArrayOperatorFactory(expression);
 	}
 
+	/**
+	 * Take the given {@link Collection values} {@link AggregationExpression}.
+	 *
+	 * @param values must not be {@literal null}.
+	 * @return new instance of {@link ArrayOperatorFactory}.
+	 * @since 2.2
+	 */
+	public static ArrayOperatorFactory arrayOf(Collection<?> values) {
+		return new ArrayOperatorFactory(values);
+	}
+
 	/**
 	 * @author Christoph Strobl
 	 */
 	public static class ArrayOperatorFactory {
 
-		private final String fieldReference;
-		private final AggregationExpression expression;
+		private final @Nullable String fieldReference;
+		private final @Nullable AggregationExpression expression;
+		private final @Nullable Collection values;
 
 		/**
 		 * Creates new {@link ArrayOperatorFactory} for given {@literal fieldReference}.
@@ -75,6 +89,7 @@ public class ArrayOperators {
 			Assert.notNull(fieldReference, "FieldReference must not be null!");
 			this.fieldReference = fieldReference;
 			this.expression = null;
+			this.values = null;
 		}
 
 		/**
@@ -87,6 +102,21 @@ public class ArrayOperators {
 			Assert.notNull(expression, "Expression must not be null!");
 			this.fieldReference = null;
 			this.expression = expression;
+			this.values = null;
+		}
+
+		/**
+		 * Creates new {@link ArrayOperatorFactory} for given values.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @since 2.2
+		 */
+		public ArrayOperatorFactory(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			this.fieldReference = null;
+			this.expression = null;
+			this.values = values;
 		}
 
 		/**
@@ -127,7 +157,12 @@ public class ArrayOperators {
 		}
 
 		private ArrayElemAt createArrayElemAt() {
-			return usesFieldRef() ? ArrayElemAt.arrayOf(fieldReference) : ArrayElemAt.arrayOf(expression);
+
+			if (usesFieldRef()) {
+				return ArrayElemAt.arrayOf(fieldReference);
+			}
+
+			return usesExpression() ? ArrayElemAt.arrayOf(expression) : ArrayElemAt.arrayOf(values);
 		}
 
 		/**
@@ -157,7 +192,12 @@ public class ArrayOperators {
 		}
 
 		private ConcatArrays createConcatArrays() {
-			return usesFieldRef() ? ConcatArrays.arrayOf(fieldReference) : ConcatArrays.arrayOf(expression);
+
+			if (usesFieldRef()) {
+				return ConcatArrays.arrayOf(fieldReference);
+			}
+
+			return usesExpression() ? ConcatArrays.arrayOf(expression) : ConcatArrays.arrayOf(values);
 		}
 
 		/**
@@ -167,7 +207,13 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public AsBuilder filter() {
-			return Filter.filter(fieldReference);
+
+			if (usesFieldRef()) {
+				return Filter.filter(fieldReference);
+			}
+
+			Assert.state(values != null, "Values must not be null!");
+			return Filter.filter(new ArrayList<>(values));
 		}
 
 		/**
@@ -176,6 +222,9 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public IsArray isArray() {
+
+			Assert.state(values == null, "Does it make sense to call isArray on an array? Maybe just skip it?");
+
 			return usesFieldRef() ? IsArray.isArray(fieldReference) : IsArray.isArray(expression);
 		}
 
@@ -185,7 +234,12 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public Size length() {
-			return usesFieldRef() ? Size.lengthOfArray(fieldReference) : Size.lengthOfArray(expression);
+
+			if (usesFieldRef()) {
+				return Size.lengthOfArray(fieldReference);
+			}
+
+			return usesExpression() ? Size.lengthOfArray(expression) : Size.lengthOfArray(values);
 		}
 
 		/**
@@ -194,7 +248,12 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public Slice slice() {
-			return usesFieldRef() ? Slice.sliceArrayOf(fieldReference) : Slice.sliceArrayOf(expression);
+
+			if (usesFieldRef()) {
+				return Slice.sliceArrayOf(fieldReference);
+			}
+
+			return usesExpression() ? Slice.sliceArrayOf(expression) : Slice.sliceArrayOf(values);
 		}
 
 		/**
@@ -205,8 +264,13 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public IndexOfArray indexOf(Object value) {
-			return usesFieldRef() ? IndexOfArray.arrayOf(fieldReference).indexOf(value)
-					: IndexOfArray.arrayOf(expression).indexOf(value);
+
+			if (usesFieldRef()) {
+				return IndexOfArray.arrayOf(fieldReference).indexOf(value);
+			}
+
+			return usesExpression() ? IndexOfArray.arrayOf(expression).indexOf(value)
+					: IndexOfArray.arrayOf(values).indexOf(value);
 		}
 
 		/**
@@ -215,7 +279,13 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public ReverseArray reverse() {
-			return usesFieldRef() ? ReverseArray.reverseArrayOf(fieldReference) : ReverseArray.reverseArrayOf(expression);
+
+			if (usesFieldRef()) {
+				return ReverseArray.reverseArrayOf(fieldReference);
+			}
+
+			return usesExpression() ? ReverseArray.reverseArrayOf(expression)
+					: ReverseArray.reverseArrayOf(Collections.singletonList(values));
 		}
 
 		/**
@@ -253,7 +323,12 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public Zip zipWith(Object... arrays) {
-			return (usesFieldRef() ? Zip.arrayOf(fieldReference) : Zip.arrayOf(expression)).zip(arrays);
+
+			if (usesFieldRef()) {
+				return Zip.arrayOf(fieldReference).zip(arrays);
+			}
+
+			return (usesExpression() ? Zip.arrayOf(expression) : Zip.arrayOf(values)).zip(arrays);
 		}
 
 		/**
@@ -264,7 +339,12 @@ public class ArrayOperators {
 		 * @return
 		 */
 		public In containsValue(Object value) {
-			return (usesFieldRef() ? In.arrayOf(fieldReference) : In.arrayOf(expression)).containsValue(value);
+
+			if (usesFieldRef()) {
+				return In.arrayOf(fieldReference).containsValue(value);
+			}
+
+			return (usesExpression() ? In.arrayOf(expression) : In.arrayOf(values)).containsValue(value);
 		}
 
 		/**
@@ -276,8 +356,11 @@ public class ArrayOperators {
 		 */
 		public ArrayToObject toObject() {
 
-			return usesFieldRef() ? ArrayToObject.arrayValueOfToObject(fieldReference)
-					: ArrayToObject.arrayValueOfToObject(expression);
+			if (usesFieldRef()) {
+				return ArrayToObject.arrayValueOfToObject(fieldReference);
+			}
+
+			return usesExpression() ? ArrayToObject.arrayValueOfToObject(expression) : ArrayToObject.arrayToObject(values);
 		}
 
 		/**
@@ -294,9 +377,20 @@ public class ArrayOperators {
 			Reduce startingWith(Object initialValue);
 		}
 
+		/**
+		 * @return {@literal true} if {@link #fieldReference} is not {@literal null}.
+		 */
 		private boolean usesFieldRef() {
 			return fieldReference != null;
 		}
+
+		/**
+		 * @return {@literal true} if {@link #expression} is not {@literal null}.
+		 * @since 2.2
+		 */
+		private boolean usesExpression() {
+			return expression != null;
+		}
 	}
 
 	/**
@@ -339,6 +433,19 @@ public class ArrayOperators {
 			return new ArrayElemAt(Collections.singletonList(expression));
 		}
 
+		/**
+		 * Creates new {@link ArrayElemAt}.
+		 *
+		 * @param values The array members. Must not be {@literal null}.
+		 * @return new instance of {@link ArrayElemAt}.
+		 * @since 2.2
+		 */
+		public static ArrayElemAt arrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			return new ArrayElemAt(Collections.singletonList(values));
+		}
+
 		public ArrayElemAt elementAt(int index) {
 			return new ArrayElemAt(append(index));
 		}
@@ -396,6 +503,19 @@ public class ArrayOperators {
 			return new ConcatArrays(Collections.singletonList(expression));
 		}
 
+		/**
+		 * Creates new {@link ConcatArrays}.
+		 *
+		 * @param values The array members. Must not be {@literal null}.
+		 * @return new instance of {@link ConcatArrays}.
+		 * @since 2.2
+		 */
+		public static ConcatArrays arrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			return new ConcatArrays(Collections.singletonList(values));
+		}
+
 		public ConcatArrays concat(String arrayFieldReference) {
 
 			Assert.notNull(arrayFieldReference, "ArrayFieldReference must not be null!");
@@ -740,6 +860,19 @@ public class ArrayOperators {
 			Assert.notNull(expression, "Expression must not be null!");
 			return new Size(expression);
 		}
+
+		/**
+		 * Creates new {@link Size}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link Size}.
+		 * @since 2.2
+		 */
+		public static Size lengthOfArray(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			return new Size(Collections.singletonList(values));
+		}
 	}
 
 	/**
@@ -782,6 +915,19 @@ public class ArrayOperators {
 			return new Slice(Collections.singletonList(expression));
 		}
 
+		/**
+		 * Creates new {@link Slice}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link Slice}.
+		 * @since 2.2
+		 */
+		public static Slice sliceArrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			return new Slice(Collections.singletonList(values));
+		}
+
 		public Slice itemCount(int nrElements) {
 			return new Slice(append(nrElements));
 		}
@@ -852,6 +998,19 @@ public class ArrayOperators {
 			return new IndexOfArrayBuilder(expression);
 		}
 
+		/**
+		 * Start creating new {@link IndexOfArray}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link IndexOfArray}.
+		 * @since 2.2
+		 */
+		public static IndexOfArrayBuilder arrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+			return new IndexOfArrayBuilder(values);
+		}
+
 		public IndexOfArray within(Range<Long> range) {
 			return new IndexOfArray(append(AggregationUtils.toRangeValues(range)));
 		}
@@ -1006,6 +1165,17 @@ public class ArrayOperators {
 		public static ReverseArray reverseArrayOf(AggregationExpression expression) {
 			return new ReverseArray(expression);
 		}
+
+		/**
+		 * Creates new {@link ReverseArray}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link ReverseArray}.
+		 * @since 2.2
+		 */
+		public static ReverseArray reverseArrayOf(Collection<?> values) {
+			return new ReverseArray(values);
+		}
 	}
 
 	/**
@@ -1358,6 +1528,19 @@ public class ArrayOperators {
 			return new ZipBuilder(expression);
 		}
 
+		/**
+		 * Start creating new {@link Zip}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link Zip}.
+		 * @since 2.2
+		 */
+		public static ZipBuilder arrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Expression must not be null!");
+			return new ZipBuilder(values);
+		}
+
 		/**
 		 * Create new {@link Zip} and set the {@code useLongestLength} property to {@literal true}.
 		 *
@@ -1442,6 +1625,10 @@ public class ArrayOperators {
 	 * {@link AggregationExpression} for {@code $in}.
 	 *
 	 * @author Christoph Strobl
+	 * @author Shashank Sharma
+	 * @see <a href=
+	 *      "https://docs.mongodb.com/manual/reference/operator/aggregation/in/">https://docs.mongodb.com/manual/reference/operator/aggregation/in/</a>
+	 * @since 2.2
 	 */
 	public static class In extends AbstractAggregationExpression {
 
@@ -1460,18 +1647,14 @@ public class ArrayOperators {
 		 * @param fieldReference must not be {@literal null}.
 		 * @return
 		 */
-		public static InBuilder arrayOf(final String fieldReference) {
+		public static InBuilder arrayOf(String fieldReference) {
 
 			Assert.notNull(fieldReference, "FieldReference must not be null!");
 
-			return new InBuilder() {
+			return value -> {
 
-				@Override
-				public In containsValue(Object value) {
-
-					Assert.notNull(value, "Value must not be null!");
-					return new In(Arrays.asList(value, Fields.field(fieldReference)));
-				}
+				Assert.notNull(value, "Value must not be null!");
+				return new In(Arrays.asList(value, Fields.field(fieldReference)));
 			};
 		}
 
@@ -1481,18 +1664,34 @@ public class ArrayOperators {
 		 * @param expression must not be {@literal null}.
 		 * @return
 		 */
-		public static InBuilder arrayOf(final AggregationExpression expression) {
+		public static InBuilder arrayOf(AggregationExpression expression) {
 
 			Assert.notNull(expression, "Expression must not be null!");
 
-			return new InBuilder() {
+			return value -> {
 
-				@Override
-				public In containsValue(Object value) {
+				Assert.notNull(value, "Value must not be null!");
 
-					Assert.notNull(value, "Value must not be null!");
-					return new In(Arrays.asList(value, expression));
-				}
+				return new In(Arrays.asList(value, expression));
+			};
+		}
+
+		/**
+		 * Support for Aggregation In Search an Element in List of Objects to Filter Start creating {@link In}.
+		 *
+		 * @param values must not be {@literal null}.
+		 * @return new instance of {@link InBuilder}.
+		 * @since 2.2
+		 */
+		public static InBuilder arrayOf(Collection<?> values) {
+
+			Assert.notNull(values, "Values must not be null!");
+
+			return value -> {
+
+				Assert.notNull(value, "Value must not be null!");
+
+				return new In(Arrays.asList(value, values));
 			};
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ExposedFieldsAggregationOperationContext.java

@@ -56,11 +56,11 @@ class ExposedFieldsAggregationOperationContext implements AggregationOperationCo
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document, java.lang.Class)
 	 */
 	@Override
-	public Document getMappedObject(Document document) {
-		return rootContext.getMappedObject(document);
+	public Document getMappedObject(Document document, @Nullable Class<?> type) {
+		return rootContext.getMappedObject(document, type);
 	}
 
 	/*
@@ -86,6 +86,15 @@ class ExposedFieldsAggregationOperationContext implements AggregationOperationCo
 		return getReference(null, name);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getFields(java.lang.Class)
+	 */
+	@Override
+	public Fields getFields(Class<?> type) {
+		return rootContext.getFields(type);
+	}
+
 	/**
 	 * Returns a {@link FieldReference} to the given {@link Field} with the given {@code name}.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Field.java

@@ -46,7 +46,7 @@ public interface Field {
 
 	/**
 	 * @return true if the field name references a local value such as {@code $$this}.
-	 * @since 2.1.11
+	 * @since 2.2
 	 */
 	default boolean isInternal() {
 		return false;

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Fields.java

@@ -112,7 +112,7 @@ public final class Fields implements Iterable<Field> {
 		this.fields = verify(fields);
 	}
 
-	private static final List<Field> verify(List<Field> fields) {
+	private static List<Field> verify(List<Field> fields) {
 
 		Map<String, Field> reference = new HashMap<String, Field>();
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/GeoNearOperation.java

@@ -15,10 +15,15 @@
  */
 package org.springframework.data.mongodb.core.aggregation;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
 import org.bson.Document;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.NumberUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -89,6 +94,15 @@ public class GeoNearOperation implements AggregationOperation {
 	public Document toDocument(AggregationOperationContext context) {
 
 		Document command = context.getMappedObject(nearQuery.toDocument());
+
+		if(command.containsKey("query")) {
+			command.replace("query", context.getMappedObject(command.get("query", Document.class)));
+		}
+
+		if(command.containsKey("collation")) {
+			command.remove("collation");
+		}
+
 		command.put("distanceField", distanceField);
 
 		if (StringUtils.hasText(indexKey)) {
@@ -97,4 +111,28 @@ public class GeoNearOperation implements AggregationOperation {
 
 		return new Document("$geoNear", command);
 	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperation#toPipelineStages(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+	 */
+	@Override
+	public List<Document> toPipelineStages(AggregationOperationContext context) {
+
+		Document command = toDocument(context);
+		Number limit = (Number) command.get("$geoNear", Document.class).remove("num");
+
+		List<Document> stages = new ArrayList<>();
+		stages.add(command);
+
+		if(nearQuery.getSkip() != null && nearQuery.getSkip() > 0){
+			stages.add(new Document("$skip", nearQuery.getSkip()));
+		}
+
+		if(limit != null) {
+			stages.add(new Document("$limit", limit.longValue()));
+		}
+
+		return stages;
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/GraphLookupOperation.java

@@ -128,7 +128,13 @@ public class GraphLookupOperation implements InheritsFieldsAggregationOperation
 	 */
 	@Override
 	public ExposedFields getFields() {
-		return ExposedFields.from(new ExposedField(as, true));
+
+		List<ExposedField> fields = new ArrayList<>(2);
+		fields.add(new ExposedField(as, true));
+		if(depthField != null) {
+			fields.add(new ExposedField(depthField, true));
+		}
+		return ExposedFields.from(fields.toArray(new ExposedField[0]));
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/NestedDelegatingExpressionAggregationOperationContext.java

@@ -59,6 +59,15 @@ class NestedDelegatingExpressionAggregationOperationContext implements Aggregati
 		return delegate.getMappedObject(document);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document, java.lang.Class)
+	 */
+	@Override
+	public Document getMappedObject(Document document, Class<?> type) {
+		return delegate.getMappedObject(document, type);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getReference(org.springframework.data.mongodb.core.aggregation.Field)
@@ -94,4 +103,13 @@ class NestedDelegatingExpressionAggregationOperationContext implements Aggregati
 	public FieldReference getReference(String name) {
 		return new ExpressionFieldReference(delegate.getReference(name));
 	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getFields(java.lang.Class)
+	 */
+	@Override
+	public Fields getFields(Class<?> type) {
+		return delegate.getFields(type);
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/OutOperation.java

@@ -16,7 +16,11 @@
 package org.springframework.data.mongodb.core.aggregation;
 
 import org.bson.Document;
+
+import org.springframework.data.mongodb.util.BsonUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * Encapsulates the {@code $out}-operation.
@@ -26,18 +30,161 @@ import org.springframework.util.Assert;
  *
  * @author Nikolay Bogdanov
  * @author Christoph Strobl
- * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/out/">MongoDB Aggregation Framework: $out</a>
+ * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/out/">MongoDB Aggregation Framework:
+ *      $out</a>
  */
 public class OutOperation implements AggregationOperation {
 
+	private final @Nullable String databaseName;
 	private final String collectionName;
+	private final @Nullable Document uniqueKey;
+	private final @Nullable OutMode mode;
 
 	/**
 	 * @param outCollectionName Collection name to export the results. Must not be {@literal null}.
 	 */
 	public OutOperation(String outCollectionName) {
-		Assert.notNull(outCollectionName, "Collection name must not be null!");
-		this.collectionName = outCollectionName;
+		this(null, outCollectionName, null, null);
+	}
+
+	/**
+	 * @param databaseName Optional database name the target collection is located in. Can be {@literal null}.
+	 * @param collectionName Collection name to export the results. Must not be {@literal null}. Can be {@literal null}.
+	 * @param uniqueKey Optional unique key spec identify a document in the to collection for replacement or merge.
+	 * @param mode The mode for merging the aggregation pipeline output with the target collection. Can be
+	 *          {@literal null}. {@literal null}.
+	 * @since 2.2
+	 */
+	private OutOperation(@Nullable String databaseName, String collectionName, @Nullable Document uniqueKey,
+			@Nullable OutMode mode) {
+
+		Assert.notNull(collectionName, "Collection name must not be null!");
+
+		this.databaseName = databaseName;
+		this.collectionName = collectionName;
+		this.uniqueKey = uniqueKey;
+		this.mode = mode;
+	}
+
+	/**
+	 * Optionally specify the database of the target collection. <br />
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @param database can be {@literal null}. Defaulted to aggregation target database.
+	 * @return new instance of {@link OutOperation}.
+	 * @since 2.2
+	 */
+	public OutOperation in(@Nullable String database) {
+		return new OutOperation(database, collectionName, uniqueKey, mode);
+	}
+
+	/**
+	 * Optionally specify the field that uniquely identifies a document in the target collection. <br />
+	 * For convenience the given {@literal key} can either be a single field name or the Json representation of a key
+	 * {@link Document}.
+	 *
+	 * <pre class="code">
+	 *
+	 * // {
+	 * //    "field-1" : 1
+	 * // }
+	 * .uniqueKey("field-1")
+	 *
+	 * // {
+	 * //    "field-1" : 1,
+	 * //    "field-2" : 1
+	 * // }
+	 * .uniqueKey("{ 'field-1' : 1, 'field-2' : 1}")
+	 * </pre>
+	 *
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @param key can be {@literal null}. Server uses {@literal _id} when {@literal null}.
+	 * @return new instance of {@link OutOperation}.
+	 * @since 2.2
+	 */
+	public OutOperation uniqueKey(@Nullable String key) {
+
+		Document uniqueKey = key == null ? null : BsonUtils.toDocumentOrElse(key, it -> new Document(it, 1));
+		return new OutOperation(databaseName, collectionName, uniqueKey, mode);
+	}
+
+	/**
+	 * Optionally specify the fields that uniquely identifies a document in the target collection. <br />
+	 *
+	 * <pre class="code">
+	 *
+	 * // {
+	 * //    "field-1" : 1
+	 * //    "field-2" : 1
+	 * // }
+	 * .uniqueKeyOf(Arrays.asList("field-1", "field-2"))
+	 * </pre>
+	 *
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @param fields must not be {@literal null}.
+	 * @return new instance of {@link OutOperation}.
+	 * @since 2.2
+	 */
+	public OutOperation uniqueKeyOf(Iterable<String> fields) {
+
+		Assert.notNull(fields, "Fields must not be null!");
+
+		Document uniqueKey = new Document();
+		fields.forEach(it -> uniqueKey.append(it, 1));
+
+		return new OutOperation(databaseName, collectionName, uniqueKey, mode);
+	}
+
+	/**
+	 * Specify how to merge the aggregation output with the target collection. <br />
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @param mode must not be {@literal null}.
+	 * @return new instance of {@link OutOperation}.
+	 * @since 2.2
+	 */
+	public OutOperation mode(OutMode mode) {
+
+		Assert.notNull(mode, "Mode must not be null!");
+		return new OutOperation(databaseName, collectionName, uniqueKey, mode);
+	}
+
+	/**
+	 * Replace the target collection. <br />
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @return new instance of {@link OutOperation}.
+	 * @see OutMode#REPLACE_COLLECTION
+	 * @since 2.2
+	 */
+	public OutOperation replaceCollection() {
+		return mode(OutMode.REPLACE_COLLECTION);
+	}
+
+	/**
+	 * Replace/Upsert documents in the target collection. <br />
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @return new instance of {@link OutOperation}.
+	 * @see OutMode#REPLACE
+	 * @since 2.2
+	 */
+	public OutOperation replaceDocuments() {
+		return mode(OutMode.REPLACE);
+	}
+
+	/**
+	 * Insert documents to the target collection. <br />
+	 * <strong>NOTE:</strong> Requires MongoDB 4.2 or later.
+	 *
+	 * @return new instance of {@link OutOperation}.
+	 * @see OutMode#INSERT
+	 * @since 2.2
+	 */
+	public OutOperation insertDocuments() {
+		return mode(OutMode.INSERT);
 	}
 
 	/*
@@ -46,6 +193,62 @@ public class OutOperation implements AggregationOperation {
 	 */
 	@Override
 	public Document toDocument(AggregationOperationContext context) {
-		return new Document("$out", collectionName);
+
+		if (!requiresMongoDb42Format()) {
+			return new Document("$out", collectionName);
+		}
+
+		Assert.state(mode != null, "Mode must not be null!");
+
+		Document $out = new Document("to", collectionName) //
+				.append("mode", mode.getMongoMode());
+
+		if (StringUtils.hasText(databaseName)) {
+			$out.append("db", databaseName);
+		}
+
+		if (uniqueKey != null) {
+			$out.append("uniqueKey", uniqueKey);
+		}
+
+		return new Document("$out", $out);
+	}
+
+	private boolean requiresMongoDb42Format() {
+		return StringUtils.hasText(databaseName) || mode != null || uniqueKey != null;
+	}
+
+	/**
+	 * The mode for merging the aggregation pipeline output.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.2
+	 */
+	public enum OutMode {
+
+		/**
+		 * Write documents to the target collection. Errors if a document same uniqueKey already exists.
+		 */
+		INSERT("insertDocuments"),
+
+		/**
+		 * Update on any document in the target collection with the same uniqueKey.
+		 */
+		REPLACE("replaceDocuments"),
+
+		/**
+		 * Replaces the to collection with the output from the aggregation pipeline. Cannot be in a different database.
+		 */
+		REPLACE_COLLECTION("replaceCollection");
+
+		private String mode;
+
+		OutMode(String mode) {
+			this.mode = mode;
+		}
+
+		public String getMongoMode() {
+			return mode;
+		}
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/PrefixingDelegatingAggregationOperationContext.java

@@ -25,12 +25,13 @@ import java.util.Set;
 
 import org.bson.Document;
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link AggregationOperationContext} implementation prefixing non-command keys on root level with the given prefix.
  * Useful when mapping fields to domain specific types while having to prefix keys for query purpose.
  * <p />
- * Fields to be excluded from prefixing my be added to a {@literal denylist}.
+ * Fields to be excluded from prefixing my be added to a {@literal blacklist}.
  *
  * @author Christoph Strobl
  * @author Mark Paluch
@@ -40,18 +41,18 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 
 	private final AggregationOperationContext delegate;
 	private final String prefix;
-	private final Set<String> denylist;
+	private final Set<String> blacklist;
 
 	public PrefixingDelegatingAggregationOperationContext(AggregationOperationContext delegate, String prefix) {
 		this(delegate, prefix, Collections.emptySet());
 	}
 
 	public PrefixingDelegatingAggregationOperationContext(AggregationOperationContext delegate, String prefix,
-			Collection<String> denylist) {
+			Collection<String> blacklist) {
 
 		this.delegate = delegate;
 		this.prefix = prefix;
-		this.denylist = new HashSet<>(denylist);
+		this.blacklist = new HashSet<>(blacklist);
 	}
 
 	/*
@@ -63,6 +64,15 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 		return doPrefix(delegate.getMappedObject(document));
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document, java.lang.Class)
+	 */
+	@Override
+	public Document getMappedObject(Document document, @Nullable Class<?> type) {
+		return doPrefix(delegate.getMappedObject(document, type));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getReference(org.springframework.data.mongodb.core.aggregation.Field)
@@ -81,6 +91,15 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 		return delegate.getReference(name);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getFields(java.lang.Class)
+	 */
+	@Override
+	public Fields getFields(Class<?> type) {
+		return delegate.getFields(type);
+	}
+
 	@SuppressWarnings("unchecked")
 	private Document doPrefix(Document source) {
 
@@ -102,7 +121,7 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 	}
 
 	private String prefixKey(String key) {
-		return (key.startsWith("$") || isDenied(key)) ? key : (prefix + "." + key);
+		return (key.startsWith("$") || isBlacklisted(key)) ? key : (prefix + "." + key);
 	}
 
 	private Object prefixCollection(Collection<Object> sourceCollection) {
@@ -120,9 +139,9 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 		return prefixed;
 	}
 
-	private boolean isDenied(String key) {
+	private boolean isBlacklisted(String key) {
 
-		if (denylist.contains(key)) {
+		if (blacklist.contains(key)) {
 			return true;
 		}
 
@@ -130,8 +149,8 @@ public class PrefixingDelegatingAggregationOperationContext implements Aggregati
 			return false;
 		}
 
-		for (String denied : denylist) {
-			if (key.startsWith(denied + ".")) {
+		for (String blacklisted : blacklist) {
+			if (key.startsWith(blacklisted + ".")) {
 				return true;
 			}
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ProjectionOperation.java

@@ -20,6 +20,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.bson.Document;
 import org.springframework.data.mongodb.core.aggregation.ConditionalOperators.Cond;
@@ -73,6 +74,16 @@ public class ProjectionOperation implements FieldsExposingAggregationOperation {
 		this(NONE, ProjectionOperationBuilder.FieldProjection.from(fields));
 	}
 
+	/**
+	 * Creates a new {@link ProjectionOperation} including all top level fields of the given {@link Class type}.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @since 2.2
+	 */
+	public ProjectionOperation(Class<?> type) {
+		this(NONE, Collections.singletonList(new TypeProjection(type)));
+	}
+
 	/**
 	 * Copy constructor to allow building up {@link ProjectionOperation} instances from already existing
 	 * {@link Projection}s.
@@ -166,6 +177,48 @@ public class ProjectionOperation implements FieldsExposingAggregationOperation {
 		return new ProjectionOperation(this.projections, FieldProjection.from(fields, true));
 	}
 
+	/**
+	 * Includes the current {@link ProjectionOperation} as an array with given name. <br />
+	 * If you want to specify array values directly use {@link #andArrayOf(Object...)}.
+	 *
+	 * @param name the target property name.
+	 * @return new instance of {@link ProjectionOperation}.
+	 * @since 2.2
+	 */
+	public ProjectionOperation asArray(String name) {
+
+		return new ProjectionOperation(Collections.emptyList(),
+				Collections.singletonList(new ArrayProjection(Fields.field(name), (List) this.projections)));
+	}
+
+	/**
+	 * Includes the given values ({@link Field field references}, {@link AggregationExpression expression}, plain values)
+	 * as an array. <br />
+	 * The target property name needs to be set via {@link ArrayProjectionOperationBuilder#as(String)}.
+	 *
+	 * @param values must not be {@literal null}.
+	 * @return new instance of {@link ArrayProjectionOperationBuilder}.
+	 * @throws IllegalArgumentException if the required argument it {@literal null}.
+	 * @since 2.2
+	 */
+	public ArrayProjectionOperationBuilder andArrayOf(Object... values) {
+
+		ArrayProjectionOperationBuilder builder = new ArrayProjectionOperationBuilder(this);
+
+		for (Object value : values) {
+
+			if (value instanceof Field) {
+				builder.and((Field) value);
+			} else if (value instanceof AggregationExpression) {
+				builder.and((AggregationExpression) value);
+			} else {
+				builder.and(value);
+			}
+		}
+
+		return builder;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation#getFields()
@@ -1495,7 +1548,8 @@ public class ProjectionOperation implements FieldsExposingAggregationOperation {
 				final Field aliasedField = Fields.field(alias, this.field.getName());
 				return new OperationProjection(aliasedField, operation, values.toArray()) {
 
-					/* (non-Javadoc)
+					/* 
+					 * (non-Javadoc)
 					 * @see org.springframework.data.mongodb.core.aggregation.ProjectionOperation.ProjectionOperationBuilder.OperationProjection#getField()
 					 */
 					@Override
@@ -1695,9 +1749,164 @@ public class ProjectionOperation implements FieldsExposingAggregationOperation {
 			this.expression = expression;
 		}
 
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.aggregation.ProjectionOperation.Projection#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+		 */
 		@Override
 		public Document toDocument(AggregationOperationContext context) {
 			return new Document(field.getName(), expression.toDocument(context));
 		}
 	}
+
+	/**
+	 * A {@link Projection} including all top level fields of the given target type mapped to include potentially
+	 * deviating field names.
+	 *
+	 * @since 2.2
+	 * @author Christoph Strobl
+	 */
+	static class TypeProjection extends Projection {
+
+		private final Class<?> type;
+
+		TypeProjection(Class<?> type) {
+
+			super(Fields.field(type.getSimpleName()));
+			this.type = type;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.aggregation.ProjectionOperation.Projection#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+		 */
+		@Override
+		public Document toDocument(AggregationOperationContext context) {
+
+			Document projections = new Document();
+
+			Fields fields = context.getFields(type);
+			fields.forEach(it -> projections.append(it.getName(), 1));
+			return context.getMappedObject(projections, type);
+		}
+	}
+
+	/**
+	 * Builder for {@code array} projections.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.2
+	 */
+	public static class ArrayProjectionOperationBuilder {
+
+		private ProjectionOperation target;
+		private final List<Object> projections;
+
+		public ArrayProjectionOperationBuilder(ProjectionOperation target) {
+
+			this.target = target;
+			this.projections = new ArrayList<>();
+		}
+
+		/**
+		 * Creates a new {@link ArrayProjectionOperationBuilder} with the current {@link Projection}s and the given one.
+		 *
+		 * @param expression
+		 * @return
+		 */
+		public ArrayProjectionOperationBuilder and(AggregationExpression expression) {
+
+			Assert.notNull(expression, "AggregationExpression must not be null!");
+
+			this.projections.add(expression);
+			return this;
+		}
+
+		/**
+		 * Creates a new {@link ArrayProjectionOperationBuilder} with the current {@link Projection}s and the given one.
+		 *
+		 * @param field
+		 * @return
+		 */
+		public ArrayProjectionOperationBuilder and(Field field) {
+
+			Assert.notNull(field, "Field must not be null!");
+
+			this.projections.add(field);
+			return this;
+		}
+
+		/**
+		 * Creates a new {@link ArrayProjectionOperationBuilder} with the current {@link Projection}s and the given one.
+		 *
+		 * @param value
+		 * @return
+		 */
+		public ArrayProjectionOperationBuilder and(Object value) {
+
+			this.projections.add(value);
+			return this;
+		}
+
+		/**
+		 * Create the {@link ProjectionOperation} for the array property with given {@literal name}.
+		 *
+		 * @param name The target property name. Must not be {@literal null}.
+		 * @return new instance of {@link ArrayProjectionOperationBuilder}.
+		 */
+		public ProjectionOperation as(String name) {
+
+			return new ProjectionOperation(target.projections,
+					Collections.singletonList(new ArrayProjection(Fields.field(name), this.projections)));
+		}
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.2
+	 */
+	static class ArrayProjection extends Projection {
+
+		private final Field targetField;
+		private final List<Object> projections;
+
+		public ArrayProjection(Field targetField, List<Object> projections) {
+
+			super(targetField);
+			this.targetField = targetField;
+			this.projections = projections;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.aggregation.ProjectionOperation.Projection#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+		 */
+		@Override
+		public Document toDocument(AggregationOperationContext context) {
+
+			return new Document(targetField.getName(),
+					projections.stream().map(it -> toArrayEntry(it, context)).collect(Collectors.toList()));
+		}
+
+		private Object toArrayEntry(Object projection, AggregationOperationContext ctx) {
+
+			if (projection instanceof Field) {
+				return ctx.getReference((Field) projection).toString();
+			}
+
+			if (projection instanceof AggregationExpression) {
+				return ((AggregationExpression) projection).toDocument(ctx);
+			}
+
+			if (projection instanceof FieldProjection) {
+				return ctx.getReference(((FieldProjection) projection).getExposedField().getTarget()).toString();
+			}
+
+			if (projection instanceof Projection) {
+				((Projection) projection).toDocument(ctx);
+			}
+
+			return projection;
+		}
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/RelaxedTypeBasedAggregationOperationContext.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.aggregation;
+
+import org.springframework.data.mapping.context.InvalidPersistentPropertyPath;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.aggregation.ExposedFields.DirectFieldReference;
+import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
+import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldReference;
+import org.springframework.data.mongodb.core.convert.QueryMapper;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+
+/**
+ * A {@link TypeBasedAggregationOperationContext} with less restrictive field reference handling, suppressing
+ * {@link InvalidPersistentPropertyPath} exceptions when resolving mapped field names.
+ *
+ * @author Christoph Strobl
+ * @since 3.0
+ */
+public class RelaxedTypeBasedAggregationOperationContext extends TypeBasedAggregationOperationContext {
+
+	/**
+	 * Creates a new {@link TypeBasedAggregationOperationContext} for the given type, {@link MappingContext} and
+	 * {@link QueryMapper}.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @param mappingContext must not be {@literal null}.
+	 * @param mapper must not be {@literal null}.
+	 */
+	public RelaxedTypeBasedAggregationOperationContext(Class<?> type,
+			MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext, QueryMapper mapper) {
+		super(type, mappingContext, mapper);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.TypeBasedAggregationOperationContext#getReferenceFor(rg.springframework.data.mongodb.core.aggregation.Field)
+	 */
+	@Override
+	protected FieldReference getReferenceFor(Field field) {
+
+		try {
+			return super.getReferenceFor(field);
+		} catch (InvalidPersistentPropertyPath e) {
+			return new DirectFieldReference(new ExposedField(field, true));
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ReplaceRootOperation.java

@@ -33,7 +33,8 @@ import org.springframework.util.Assert;
  * @author Mark Paluch
  * @author Christoph Strobl
  * @since 1.10
- * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/replaceRoot/">MongoDB Aggregation Framework: $replaceRoot</a>
+ * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/replaceRoot/">MongoDB Aggregation
+ *      Framework: $replaceRoot</a>
  */
 public class ReplaceRootOperation implements FieldsExposingAggregationOperation {
 
@@ -82,7 +83,7 @@ public class ReplaceRootOperation implements FieldsExposingAggregationOperation
 	 */
 	@Override
 	public Document toDocument(AggregationOperationContext context) {
-		return new Document("$replaceRoot", new Document("newRoot", replacement.toDocumentExpression(context)));
+		return new Document("$replaceRoot", new Document("newRoot", getReplacement().toDocumentExpression(context)));
 	}
 
 	/* (non-Javadoc)
@@ -93,6 +94,16 @@ public class ReplaceRootOperation implements FieldsExposingAggregationOperation
 		return ExposedFields.from();
 	}
 
+	/**
+	 * Obtain the {@link Replacement}.
+	 *
+	 * @return never {@literal null}.
+	 * @since 3.0
+	 */
+	protected Replacement getReplacement() {
+		return replacement;
+	}
+
 	/**
 	 * Builder for {@link ReplaceRootOperation}.
 	 *
@@ -155,7 +166,7 @@ public class ReplaceRootOperation implements FieldsExposingAggregationOperation
 	 *
 	 * @author Mark Paluch
 	 */
-	public static class ReplaceRootDocumentOperation extends ReplaceRootOperation {
+	static class ReplaceRootDocumentOperation extends ReplaceRootOperation {
 
 		private final static ReplacementDocument EMPTY = new ReplacementDocument();
 		private final ReplacementDocument current;

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ReplaceWithOperation.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.aggregation;
+
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+import org.bson.Document;
+import org.springframework.util.Assert;
+
+/**
+ * Encapsulates the aggregation framework {@code $replaceRoot}-operation. <br />
+ * The operation replaces all existing fields including the {@code id} field with @{code $replaceWith}. This way it is
+ * possible to promote an embedded document to the top-level or specify a new document.
+ *
+ * @author Christoph Strobl
+ * @since 3.0
+ * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/replaceWith/">MongoDB Aggregation
+ *      Framework: $replaceWith</a>
+ */
+public class ReplaceWithOperation extends ReplaceRootOperation {
+
+	/**
+	 * Creates new instance of {@link ReplaceWithOperation}.
+	 *
+	 * @param replacement must not be {@literal null}.
+	 */
+	public ReplaceWithOperation(Replacement replacement) {
+		super(replacement);
+	}
+
+	/**
+	 * Creates new instance of {@link ReplaceWithOperation}.
+	 *
+	 * @param value must not be {@literal null}.
+	 * @return new instance of {@link ReplaceWithOperation}.
+	 */
+	public static ReplaceWithOperation replaceWithValue(Object value) {
+		return new ReplaceWithOperation((ctx) -> value);
+	}
+
+	/**
+	 * Creates new instance of {@link ReplaceWithOperation} treating a given {@link String} {@literal value} as a
+	 * {@link Field field reference}.
+	 *
+	 * @param value must not be {@literal null}.
+	 * @return
+	 */
+	public static ReplaceWithOperation replaceWithValueOf(Object value) {
+
+		Assert.notNull(value, "Value must not be null!");
+		return new ReplaceWithOperation((ctx) -> {
+
+			Object target = value instanceof String ? Fields.field((String) value) : value;
+			return computeValue(target, ctx);
+		});
+	}
+
+	private static Object computeValue(Object value, AggregationOperationContext context) {
+
+		if (value instanceof Field) {
+			return context.getReference((Field) value).toString();
+		}
+		if (value instanceof AggregationExpression) {
+			return ((AggregationExpression) value).toDocument(context);
+		}
+		if (value instanceof Collection) {
+			return ((Collection) value).stream().map(it -> computeValue(it, context)).collect(Collectors.toList());
+		}
+
+		return value;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperation#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+	 */
+	@Override
+	public Document toDocument(AggregationOperationContext context) {
+		return context.getMappedObject(new Document("$replaceWith", getReplacement().toDocumentExpression(context)));
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/SetOperation.java

@@ -0,0 +1,250 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.aggregation;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.stream.Collectors;
+
+import org.bson.Document;
+import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
+import org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation;
+import org.springframework.data.mongodb.core.aggregation.SetOperation.FieldAppender.ValueAppender;
+import org.springframework.lang.Nullable;
+
+/**
+ * Adds new fields to documents. {@code $set} outputs documents that contain all existing fields from the input
+ * documents and newly added fields.
+ * 
+ * <pre class="code">
+ * SetOperation.set("totalHomework").toValue("A+").and().set("totalQuiz").toValue("B-")
+ * </pre>
+ *
+ * @author Christoph Strobl
+ * @since 3.0
+ * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/set/">MongoDB Aggregation Framework:
+ *      $set</a>
+ */
+public class SetOperation implements InheritsFieldsAggregationOperation {
+
+	private Map<Object, Object> valueMap;
+	private ExposedFields exposedFields = ExposedFields.empty();
+
+	/**
+	 * Create new instance of {@link SetOperation} adding map keys as exposed fields.
+	 *
+	 * @param source must not be {@literal null}.
+	 */
+	private SetOperation(Map<Object, Object> source) {
+
+		this.valueMap = new LinkedHashMap<>(source);
+		for (Object key : source.keySet()) {
+			this.exposedFields = add(key);
+		}
+	}
+
+	/**
+	 * Create new instance of {@link SetOperation}
+	 *
+	 * @param field must not be {@literal null}.
+	 * @param value can be {@literal null}.
+	 */
+	public SetOperation(Object field, @Nullable Object value) {
+		this(Collections.singletonMap(field, value));
+	}
+
+	/**
+	 * Define the {@link SetOperation} via {@link FieldAppender}.
+	 *
+	 * @return new instance of {@link FieldAppender}.
+	 */
+	public static FieldAppender builder() {
+		return new FieldAppender();
+	}
+
+	/**
+	 * Concatenate another field to set.
+	 *
+	 * @param field must not be {@literal null}.
+	 * @return new instance of {@link ValueAppender}.
+	 */
+	public static ValueAppender set(String field) {
+		return new FieldAppender().set(field);
+	}
+
+	/**
+	 * Append the value for a specific field to the operation.
+	 *
+	 * @param field the target field to set.
+	 * @param value the value to assign.
+	 * @return new instance of {@link SetOperation}.
+	 */
+	public SetOperation set(Object field, Object value) {
+
+		LinkedHashMap<Object, Object> target = new LinkedHashMap<>(this.valueMap);
+		target.put(field, value);
+
+		return new SetOperation(target);
+	}
+
+	/**
+	 * Concatenate additional fields to set.
+	 *
+	 * @return new instance of {@link FieldAppender}.
+	 */
+	public FieldAppender and() {
+		return new FieldAppender(this.valueMap);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperation#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+	 */
+	@Override
+	public Document toDocument(AggregationOperationContext context) {
+
+		InheritingExposedFieldsAggregationOperationContext operationContext = new InheritingExposedFieldsAggregationOperationContext(
+				exposedFields, context);
+
+		if (valueMap.size() == 1) {
+			return context
+					.getMappedObject(new Document("$set", toSetEntry(valueMap.entrySet().iterator().next(), operationContext)));
+		}
+
+		Document $set = new Document();
+		valueMap.entrySet().stream().map(it -> toSetEntry(it, operationContext)).forEach($set::putAll);
+		return context.getMappedObject(new Document("$set", $set));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation#getFields()
+	 */
+	@Override
+	public ExposedFields getFields() {
+		return exposedFields;
+	}
+
+	private ExposedFields add(Object field) {
+
+		if (field instanceof Field) {
+			return exposedFields.and(new ExposedField((Field) field, true));
+		}
+		if (field instanceof String) {
+			return exposedFields.and(new ExposedField(Fields.field((String) field), true));
+		}
+
+		throw new IllegalArgumentException(String.format("Expected %s to be a field/property.", field));
+	}
+
+	private static Document toSetEntry(Entry<Object, Object> entry, AggregationOperationContext context) {
+
+		String field = entry.getKey() instanceof String ? context.getReference((String) entry.getKey()).getRaw()
+				: context.getReference((Field) entry.getKey()).getRaw();
+
+		Object value = computeValue(entry.getValue(), context);
+
+		return new Document(field, value);
+	}
+
+	private static Object computeValue(Object value, AggregationOperationContext context) {
+
+		if (value instanceof Field) {
+			return context.getReference((Field) value).toString();
+		}
+		if (value instanceof AggregationExpression) {
+			return ((AggregationExpression) value).toDocument(context);
+		}
+		if (value instanceof Collection) {
+			return ((Collection) value).stream().map(it -> computeValue(it, context)).collect(Collectors.toList());
+		}
+
+		return value;
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 3.0
+	 */
+	public static class FieldAppender {
+
+		private final Map<Object, Object> valueMap;
+
+		private FieldAppender() {
+			this.valueMap = new LinkedHashMap<>();
+		}
+
+		private FieldAppender(Map<Object, Object> source) {
+			this.valueMap = new LinkedHashMap<>(source);
+		}
+
+		/**
+		 * Define the field to set.
+		 *
+		 * @param field must not be {@literal null}.
+		 * @return new instance of {@link ValueAppender}.
+		 */
+		public ValueAppender set(String field) {
+
+			return new ValueAppender() {
+
+				@Override
+				public SetOperation toValue(Object value) {
+
+					valueMap.put(field, value);
+					return FieldAppender.this.build();
+				}
+
+				@Override
+				public SetOperation toValueOf(Object value) {
+
+					valueMap.put(field, value instanceof String ? Fields.fields((String) value) : value);
+					return FieldAppender.this.build();
+				}
+			};
+		}
+
+		private SetOperation build() {
+			return new SetOperation(valueMap);
+		}
+
+		/**
+		 * @author Christoph Strobl
+		 * @since 3.0
+		 */
+		public interface ValueAppender {
+
+			/**
+			 * Define the value to assign as is.
+			 *
+			 * @param value can be {@literal null}.
+			 * @return new instance of {@link SetOperation}.
+			 */
+			SetOperation toValue(@Nullable Object value);
+
+			/**
+			 * Define the value to assign. Plain {@link String} values are treated as {@link Field field references}.
+			 *
+			 * @param value must not be {@literal null}.
+			 * @return new instance of {@link SetOperation}.
+			 */
+			SetOperation toValueOf(Object value);
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/TypeBasedAggregationOperationContext.java

@@ -17,9 +17,11 @@ package org.springframework.data.mongodb.core.aggregation;
 
 import static org.springframework.data.mongodb.core.aggregation.Fields.*;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.bson.Document;
 import org.springframework.data.mapping.PersistentPropertyPath;
-import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.DirectFieldReference;
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
@@ -27,6 +29,7 @@ import org.springframework.data.mongodb.core.aggregation.ExposedFields.FieldRefe
 import org.springframework.data.mongodb.core.convert.QueryMapper;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -70,7 +73,16 @@ public class TypeBasedAggregationOperationContext implements AggregationOperatio
 	 */
 	@Override
 	public Document getMappedObject(Document document) {
-		return mapper.getMappedObject(document, mappingContext.getPersistentEntity(type));
+		return getMappedObject(document, type);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getMappedObject(org.bson.Document, java.lang.Class)
+	 */
+	@Override
+	public Document getMappedObject(Document document, @Nullable Class<?> type) {
+		return mapper.getMappedObject(document, type != null ? mappingContext.getPersistentEntity(type) : null);
 	}
 
 	/*
@@ -79,8 +91,6 @@ public class TypeBasedAggregationOperationContext implements AggregationOperatio
 	 */
 	@Override
 	public FieldReference getReference(Field field) {
-
-		PropertyPath.from(field.getTarget(), type);
 		return getReferenceFor(field);
 	}
 
@@ -93,7 +103,31 @@ public class TypeBasedAggregationOperationContext implements AggregationOperatio
 		return getReferenceFor(field(name));
 	}
 
-	private FieldReference getReferenceFor(Field field) {
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.aggregation.AggregationOperationContext#getFields(java.lang.Class)
+	 */
+	@Override
+	public Fields getFields(Class<?> type) {
+
+		Assert.notNull(type, "Type must not be null!");
+
+		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(type);
+
+		if (entity == null) {
+			return AggregationOperationContext.super.getFields(type);
+		}
+
+		List<String> fields = new ArrayList<>();
+
+		for (MongoPersistentProperty property : entity) {
+			fields.add(property.getName());
+		}
+
+		return Fields.fields(fields.toArray(new String[0]));
+	}
+
+	protected FieldReference getReferenceFor(Field field) {
 
 		PersistentPropertyPath<MongoPersistentProperty> propertyPath = mappingContext
 				.getPersistentPropertyPath(field.getTarget(), type);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/UnsetOperation.java

@@ -0,0 +1,144 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.aggregation;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.bson.Document;
+import org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation;
+import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+
+/**
+ * Removes fields from documents.
+ *
+ * @author Christoph Strobl
+ * @since 3.0
+ * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/unset/">MongoDB Aggregation Framework:
+ *      $unset</a>
+ */
+public class UnsetOperation implements InheritsFieldsAggregationOperation {
+
+	private final Collection<Object> fields;
+
+	/**
+	 * Create new instance of {@link UnsetOperation}.
+	 * 
+	 * @param fields must not be {@literal null}.
+	 */
+	public UnsetOperation(Collection<Object> fields) {
+
+		Assert.notNull(fields, "Fields must not be null!");
+		Assert.noNullElements(fields, "Fields must not contain null values.");
+
+		this.fields = fields;
+	}
+
+	/**
+	 * Create new instance of {@link UnsetOperation}.
+	 *
+	 * @param fields must not be {@literal null}.
+	 * @return new instance of {@link UnsetOperation}.
+	 */
+	public static UnsetOperation unset(String... fields) {
+		return new UnsetOperation(Arrays.asList(fields));
+	}
+
+	/**
+	 * Also unset the given fields.
+	 *
+	 * @param fields must not be {@literal null}.
+	 * @return new instance of {@link UnsetOperation}.
+	 */
+	public UnsetOperation and(String... fields) {
+
+		List<Object> target = new ArrayList<>(this.fields);
+		CollectionUtils.mergeArrayIntoCollection(fields, target);
+		return new UnsetOperation(target);
+	}
+
+	/**
+	 * Also unset the given fields.
+	 *
+	 * @param fields must not be {@literal null}.
+	 * @return new instance of {@link UnsetOperation}.
+	 */
+	public UnsetOperation and(Field... fields) {
+
+		List<Object> target = new ArrayList<>(this.fields);
+		CollectionUtils.mergeArrayIntoCollection(fields, target);
+		return new UnsetOperation(target);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *  @see org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation#getFields()
+	 */
+	@Override
+	public ExposedFields getFields() {
+		return ExposedFields.from();
+	}
+
+	Collection<String> removedFieldNames() {
+
+		List<String> fieldNames = new ArrayList<>(fields.size());
+		for (Object it : fields) {
+			if (it instanceof Field) {
+				fieldNames.add(((Field) it).getName());
+			} else {
+				fieldNames.add(it.toString());
+			}
+		}
+		return fieldNames;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *  @see org.springframework.data.mongodb.core.aggregation.AggregationOperation#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
+	 */
+	@Override
+	public Document toDocument(AggregationOperationContext context) {
+
+		if (fields.size() == 1) {
+			return new Document("$unset", computeFieldName(fields.iterator().next(), context));
+		}
+
+		return new Document("$unset",
+				fields.stream().map(it -> computeFieldName(it, context)).collect(Collectors.toList()));
+	}
+
+	private Object computeFieldName(Object field, AggregationOperationContext context) {
+
+		if (field instanceof Field) {
+			return context.getReference((Field) field).getRaw();
+		}
+
+		if (field instanceof AggregationExpression) {
+			return ((AggregationExpression) field).toDocument(context);
+		}
+
+		if (field instanceof String) {
+			return context.getReference((String) field).getRaw();
+		}
+
+		return field;
+	}
+
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/AbstractMongoConverter.java

@@ -16,12 +16,15 @@
 package org.springframework.data.mongodb.core.convert;
 
 import java.math.BigInteger;
+import java.util.Date;
 
+import org.bson.types.Code;
 import org.bson.types.ObjectId;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.core.convert.support.GenericConversionService;
+import org.springframework.data.convert.ConverterBuilder;
 import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.convert.EntityInstantiators;
 import org.springframework.data.mongodb.core.convert.MongoConverters.BigIntegerToObjectIdConverter;
@@ -93,6 +96,24 @@ public abstract class AbstractMongoConverter implements MongoConverter, Initiali
 			conversionService.addConverter(BigIntegerToObjectIdConverter.INSTANCE);
 		}
 
+		if (!conversionService.canConvert(Date.class, Long.class)) {
+			conversionService
+					.addConverter(ConverterBuilder.writing(Date.class, Long.class, Date::getTime).getWritingConverter());
+		}
+
+		if (!conversionService.canConvert(Long.class, Date.class)) {
+			conversionService.addConverter(ConverterBuilder.reading(Long.class, Date.class, Date::new).getReadingConverter());
+		}
+
+		if (!conversionService.canConvert(ObjectId.class, Date.class)) {
+
+			conversionService.addConverter(
+					ConverterBuilder.reading(ObjectId.class, Date.class, objectId -> new Date(objectId.getTimestamp()))
+							.getReadingConverter());
+		}
+
+		conversionService
+				.addConverter(ConverterBuilder.reading(Code.class, String.class, Code::getCode).getReadingConverter());
 		conversions.registerConvertersIn(conversionService);
 	}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/DefaultDbRefResolver.java

@@ -202,7 +202,7 @@ public class DefaultDbRefResolver implements DbRefResolver {
 		proxyFactory.addInterface(propertyType);
 		proxyFactory.addAdvice(interceptor);
 
-		return handler.populateId(property, dbref, proxyFactory.getProxy(LazyLoadingProxy.class.getClassLoader()));
+		return handler.populateId(property, dbref, proxyFactory.getProxy());
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/DefaultMongoTypeMapper.java

@@ -15,13 +15,16 @@
  */
 package org.springframework.data.mongodb.core.convert;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.UnaryOperator;
 
 import org.bson.Document;
 import org.bson.conversions.Bson;
+
+import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.convert.DefaultTypeMapper;
 import org.springframework.data.convert.SimpleTypeInformationMapper;
 import org.springframework.data.convert.TypeAliasAccessor;
@@ -58,21 +61,58 @@ public class DefaultMongoTypeMapper extends DefaultTypeMapper<Bson> implements M
 
 	private final TypeAliasAccessor<Bson> accessor;
 	private final @Nullable String typeKey;
+	private UnaryOperator<Class<?>> writeTarget = UnaryOperator.identity();
 
+	/**
+	 * Create a new {@link MongoTypeMapper} with fully-qualified type hints using {@code _class}.
+	 */
 	public DefaultMongoTypeMapper() {
 		this(DEFAULT_TYPE_KEY);
 	}
 
+	/**
+	 * Create a new {@link MongoTypeMapper} with fully-qualified type hints using {@code typeKey}.
+	 *
+	 * @param typeKey name of the field to read and write type hints. Can be {@literal null} to disable type hints.
+	 */
 	public DefaultMongoTypeMapper(@Nullable String typeKey) {
-		this(typeKey, Arrays.asList(new SimpleTypeInformationMapper()));
+		this(typeKey, Collections.singletonList(new SimpleTypeInformationMapper()));
 	}
 
+	/**
+	 * Create a new {@link MongoTypeMapper} with fully-qualified type hints using {@code typeKey}.
+	 *
+	 * @param typeKey name of the field to read and write type hints. Can be {@literal null} to disable type hints.
+	 * @param mappingContext the mapping context.
+	 */
 	public DefaultMongoTypeMapper(@Nullable String typeKey,
 			MappingContext<? extends PersistentEntity<?, ?>, ?> mappingContext) {
 		this(typeKey, new DocumentTypeAliasAccessor(typeKey), mappingContext,
-				Arrays.asList(new SimpleTypeInformationMapper()));
+				Collections.singletonList(new SimpleTypeInformationMapper()));
 	}
 
+	/**
+	 * Create a new {@link MongoTypeMapper} with fully-qualified type hints using {@code typeKey}. Uses
+	 * {@link UnaryOperator} to apply {@link CustomConversions}.
+	 *
+	 * @param typeKey name of the field to read and write type hints. Can be {@literal null} to disable type hints.
+	 * @param mappingContext the mapping context to look up types using type hints.
+	 * @see MappingMongoConverter#getWriteTarget(Class)
+	 */
+	public DefaultMongoTypeMapper(@Nullable String typeKey,
+			MappingContext<? extends PersistentEntity<?, ?>, ?> mappingContext, UnaryOperator<Class<?>> writeTarget) {
+		this(typeKey, new DocumentTypeAliasAccessor(typeKey), mappingContext,
+				Collections.singletonList(new SimpleTypeInformationMapper()));
+		this.writeTarget = writeTarget;
+	}
+
+	/**
+	 * Create a new {@link MongoTypeMapper} with fully-qualified type hints using {@code typeKey}. Uses
+	 * {@link TypeInformationMapper} to map type hints.
+	 *
+	 * @param typeKey name of the field to read and write type hints. Can be {@literal null} to disable type hints.
+	 * @param mappers
+	 */
 	public DefaultMongoTypeMapper(@Nullable String typeKey, List<? extends TypeInformationMapper> mappers) {
 		this(typeKey, new DocumentTypeAliasAccessor(typeKey), null, mappers);
 	}
@@ -120,6 +160,15 @@ public class DefaultMongoTypeMapper extends DefaultTypeMapper<Bson> implements M
 		accessor.writeTypeTo(result, new Document("$in", restrictedMappedTypes));
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.convert.MongoTypeMapper#getWriteTargetTypeFor(java.lang.Class)
+	 */
+	@Override
+	public Class<?> getWriteTargetTypeFor(Class<?> source) {
+		return writeTarget.apply(source);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.DefaultTypeMapper#getFallbackTypeFor(java.lang.Object)