DATAMONGO-2302 - Release version 2.1.10 (Lovelace SR10).

Use for-loops instead of Stream API and Collectors. Reformat code. Invert condition for smoother readability.

Original pull request: #776.

.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.5.4/apache-maven-3.5.4-bin.zip

.travis.yml

@@ -13,12 +13,12 @@ before_install:
   - |-
     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:
     - PROFILE=ci
   global:
-    - MONGO_VERSION=3.7.9
+    - MONGO_VERSION=4.0.0
 
 addons:
   apt:

CI.adoc

@@ -0,0 +1,43 @@
+= Continuous Integration
+
+image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-mongodb%2Fmaster&subject=Moore%20(master)[link=https://jenkins.spring.io/view/SpringData/job/spring-data-mongodb/]
+image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-mongodb%2F2.1.x&subject=Lovelace%20(2.1.x)[link=https://jenkins.spring.io/view/SpringData/job/spring-data-mongodb/]
+image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-mongodb%2F1.10.x&subject=Ingalls%20(1.10.x)[link=https://jenkins.spring.io/view/SpringData/job/spring-data-mongodb/]
+
+== Running CI tasks locally
+
+Since this pipeline is purely Docker-based, it's easy to:
+
+* Debug what went wrong on your local machine.
+* Test out a a tweak to your test routine 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 the CI server 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="$(pwd)",target=/spring-data-mongodb-github springci/spring-data-openjdk8-with-mongodb-4.0:latest /bin/bash`
++
+This will launch the Docker image and mount your source code at `spring-data-mongodb-github`.
++
+2. `cd spring-data-mongodb-github`
++
+Next, run the tests from inside the container:
++
+3. `./mvnw clean dependency:list test -Dsort -Dbundlor.enabled=false -B` (or with whatever profile you need to test out)
+
+Since the container is binding to your source, you can make edits from your IDE and continue to run build jobs.
+
+If you need to package things up, do this:
+
+1. `docker run -it --mount type=bind,source="$(pwd)",target=/spring-data-mongodb-github springci/spring-data-openjdk8-with-mongodb-4.0:latest /bin/bash`
++
+This will launch the Docker image and mount your source code at `spring-data-mongodb-github`.
++
+2. `cd spring-data-mongodb-github`
++
+Next, package things from inside the container doing this:
++
+3. `./mvnw clean dependency:list package -Dsort -Dbundlor.enabled=false -B`
+
+NOTE: Docker containers can eat up disk space fast! From time to time, run `docker system prune` to clean out old images.

CODE_OF_CONDUCT.adoc

@@ -24,4 +24,4 @@ Instances of abusive, harassing, or otherwise unacceptable behavior may be repor
 All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances.
 Maintainers are obligated to maintain confidentiality with regard to the reporter of an incident.
 
-This Code of Conduct is adapted from the http://contributor-covenant.org[Contributor Covenant], version 1.3.0, available at http://contributor-covenant.org/version/1/3/0/[contributor-covenant.org/version/1/3/0/].
+This Code of Conduct is adapted from the https://contributor-covenant.org[Contributor Covenant], version 1.3.0, available at https://contributor-covenant.org/version/1/3/0/[contributor-covenant.org/version/1/3/0/].

Jenkinsfile

@@ -0,0 +1,123 @@
+pipeline {
+    agent none
+
+    triggers {
+        pollSCM 'H/10 * * * *'
+        upstream(upstreamProjects: "spring-data-commons/2.1.x", threshold: hudson.model.Result.SUCCESS)
+    }
+
+    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 -B'
+                    }
+                }
+
+            }
+        }
+
+        stage('Release to artifactory') {
+            when {
+                branch 'issue/*'
+                not { triggeredBy 'UpstreamCause' }
+            }
+            agent {
+                docker {
+                    image 'adoptopenjdk/openjdk8:latest'
+                    label 'data'
+                    args '-v $HOME:/tmp/jenkins-home'
+                }
+            }
+            options { timeout(time: 20, unit: 'MINUTES') }
+
+            environment {
+                ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+            }
+
+            steps {
+                sh 'rm -rf ?'
+                sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
+                        '-Dartifactory.server=https://repo.spring.io ' +
+                        "-Dartifactory.username=${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 -B'
+            }
+        }
+
+        stage('Release to artifactory with docs') {
+            when {
+                branch '2.1.x'
+            }
+            agent {
+                docker {
+                    image 'adoptopenjdk/openjdk8:latest'
+                    label 'data'
+                    args '-v $HOME:/tmp/jenkins-home'
+                }
+            }
+            options { timeout(time: 20, unit: 'MINUTES') }
+
+            environment {
+                ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+            }
+
+            steps {
+                sh 'rm -rf ?'
+                sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
+                        '-Dartifactory.server=https://repo.spring.io ' +
+                        "-Dartifactory.username=${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 -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>")
+            }
+        }
+    }
+}

README.adoc

@@ -0,0 +1,159 @@
+image:https://spring.io/badges/spring-data-mongodb/ga.svg[Spring Data MongoDB,link=https://projects.spring.io/spring-data-mongodb#quick-start] image:https://spring.io/badges/spring-data-mongodb/snapshot.svg[Spring Data MongoDB,link=https://projects.spring.io/spring-data-mongodb#quick-start]
+
+= Spring Data MongoDB image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-mongodb%2Fmaster&subject=Build[link=https://jenkins.spring.io/view/SpringData/job/spring-data-mongodb/] https://gitter.im/spring-projects/spring-data[image:https://badges.gitter.im/spring-projects/spring-data.svg[Gitter]]
+
+The primary goal of the https://projects.spring.io/spring-data[Spring Data] project is to make it easier to build Spring-powered applications that use new data access technologies such as non-relational databases, map-reduce frameworks, and cloud based data services.
+
+The Spring Data MongoDB project aims to provide a familiar and consistent Spring-based programming model for new datastores while retaining store-specific features and capabilities.
+The Spring Data MongoDB project provides integration with the MongoDB document database.
+Key functional areas of Spring Data MongoDB are a POJO centric model for interacting with a MongoDB `+Document+` and easily writing a repository style data access layer.
+
+== Code of Conduct
+
+This project is governed by the link:CODE_OF_CONDUCT.adoc[Spring Code of Conduct]. By participating, you are expected to uphold this code of conduct. Please report unacceptable behavior to spring-code-of-conduct@pivotal.io.
+
+== Getting Started
+
+Here is a quick teaser of an application using Spring Data Repositories in Java:
+
+[source,java]
+----
+public interface PersonRepository extends CrudRepository<Person, Long> {
+
+  List<Person> findByLastname(String lastname);
+
+  List<Person> findByFirstnameLike(String firstname);
+}
+
+@Service
+public class MyService {
+
+  private final PersonRepository repository;
+
+  public MyService(PersonRepository repository) {
+    this.repository = repository;
+  }
+
+  public void doWork() {
+
+    repository.deleteAll();
+
+    Person person = new Person();
+    person.setFirstname("Oliver");
+    person.setLastname("Gierke");
+    repository.save(person);
+
+    List<Person> lastNameResults = repository.findByLastname("Gierke");
+    List<Person> firstNameResults = repository.findByFirstnameLike("Oli*");
+ }
+}
+
+@Configuration
+@EnableMongoRepositories
+class ApplicationConfig extends AbstractMongoConfiguration {
+
+  @Override
+  public MongoClient mongoClient() {
+    return new MongoClient();
+  }
+
+  @Override
+  protected String getDatabaseName() {
+    return "springdata";
+  }
+}
+----
+
+=== Maven configuration
+
+Add the Maven dependency:
+
+[source,xml]
+----
+<dependency>
+  <groupId>org.springframework.data</groupId>
+  <artifactId>spring-data-mongodb</artifactId>
+  <version>${version}.RELEASE</version>
+</dependency>
+----
+
+If you'd rather like the latest snapshots of the upcoming major version, use our Maven snapshot repository and declare the appropriate dependency version.
+
+[source,xml]
+----
+<dependency>
+  <groupId>org.springframework.data</groupId>
+  <artifactId>spring-data-mongodb</artifactId>
+  <version>${version}.BUILD-SNAPSHOT</version>
+</dependency>
+
+<repository>
+  <id>spring-libs-snapshot</id>
+  <name>Spring Snapshot Repository</name>
+  <url>https://repo.spring.io/libs-snapshot</url>
+</repository>
+----
+
+== Getting Help
+
+Having trouble with Spring Data? We’d love to help!
+
+* Check the
+https://docs.spring.io/spring-data/mongodb/docs/current/reference/html/[reference documentation], and https://docs.spring.io/spring-data/mongodb/docs/current/api/[Javadocs].
+* Learn the Spring basics – Spring Data builds on Spring Framework, check the https://spring.io[spring.io] web-site for a wealth of reference documentation.
+If you are just starting out with Spring, try one of the https://spring.io/guides[guides].
+* If you are upgrading, check out the https://docs.spring.io/spring-data/mongodb/docs/current/changelog.txt[changelog] for "`new and noteworthy`" features.
+* Ask a question - we monitor https://stackoverflow.com[stackoverflow.com] for questions tagged with https://stackoverflow.com/tags/spring-data[`spring-data-mongodb`].
+You can also chat with the community on https://gitter.im/spring-projects/spring-data[Gitter].
+* Report bugs with Spring Data MongoDB at https://jira.spring.io/browse/DATAMONGO[jira.spring.io/browse/DATAMONGO].
+
+== Reporting Issues
+
+Spring Data uses JIRA as issue tracking system to record bugs and feature requests. If you want to raise an issue, please follow the recommendations below:
+
+* Before you log a bug, please search the
+https://jira.spring.io/browse/DATAMONGO[issue tracker] to see if someone has already reported the problem.
+* If the issue doesn’t already exist, https://jira.spring.io/browse/DATAMONGO[create a new issue].
+* Please provide as much information as possible with the issue report, we like to know the version of Spring Data that you are using and JVM version.
+* If you need to paste code, or include a stack trace use JIRA `{code}…{code}` escapes before and after your text.
+* If possible try to create a test-case or project that replicates the issue. Attach a link to your code or a compressed file containing your code.
+
+== Building from Source
+
+You don’t need to build from source to use Spring Data (binaries in https://repo.spring.io[repo.spring.io]), but if you want to try out the latest and greatest, Spring Data can be easily built with the https://github.com/takari/maven-wrapper[maven wrapper].
+You also need JDK 1.8.
+
+[source,bash]
+----
+ $ ./mvnw clean install
+----
+
+If you want to build with the regular `mvn` command, you will need https://maven.apache.org/run-maven/index.html[Maven v3.5.0 or above].
+
+_Also see link:CONTRIBUTING.adoc[CONTRIBUTING.adoc] if you wish to submit pull requests, and in particular please sign the https://cla.pivotal.io/sign/spring[Contributor’s Agreement] before your first non-trivial change._
+
+=== Building reference documentation
+
+Building the documentation builds also the project without running tests.
+
+[source,bash]
+----
+ $ ./mvnw clean install -Pdistribute
+----
+
+The generated documentation is available from `target/site/reference/html/index.html`.
+
+== Guides
+
+The https://spring.io/[spring.io] site contains several guides that show how to use Spring Data step-by-step:
+
+* https://spring.io/guides/gs/accessing-data-mongodb/[Accessing Data with MongoDB] is a very basic guide that shows you how to create a simple application and how to access data using repositories.
+* https://spring.io/guides/gs/accessing-mongodb-data-rest/[Accessing MongoDB Data with REST] is a guide to creating a REST web service exposing data stored in MongoDB through repositories.
+
+== Examples
+
+* https://github.com/spring-projects/spring-data-examples/[Spring Data Examples] contains example projects that explain specific features in more detail.
+
+== License
+
+Spring Data MongoDB is Open Source software released under the https://www.apache.org/licenses/LICENSE-2.0.html[Apache 2.0 license].

README.md

@@ -1,150 +0,0 @@
-[![Spring Data MongoDB](https://spring.io/badges/spring-data-mongodb/ga.svg)](http://projects.spring.io/spring-data-mongodb#quick-start)
-[![Spring Data MongoDB](https://spring.io/badges/spring-data-mongodb/snapshot.svg)](http://projects.spring.io/spring-data-mongodb#quick-start)
-
-# Spring Data MongoDB
-
-The primary goal of the [Spring Data](http://projects.spring.io/spring-data) project is to make it easier to build Spring-powered applications that use new data access technologies such as non-relational databases, map-reduce frameworks, and cloud based data services.
-
-The Spring Data MongoDB project aims to provide a familiar and consistent Spring-based programming model for new datastores while retaining store-specific features and capabilities. The Spring Data MongoDB project provides integration with the MongoDB document database. Key functional areas of Spring Data MongoDB are a POJO centric model for interacting with a MongoDB DBCollection and easily writing a repository style data access layer.
-
-## Getting Help
-
-For a comprehensive treatment of all the Spring Data MongoDB features, please refer to:
-
-* the [User Guide](http://docs.spring.io/spring-data/mongodb/docs/current/reference/html/)
-* the [JavaDocs](http://docs.spring.io/spring-data/mongodb/docs/current/api/) have extensive comments in them as well.
-* the home page of [Spring Data MongoDB](http://projects.spring.io/spring-data-mongodb) contains links to articles and other resources.
-* for more detailed questions, use [Spring Data Mongodb on Stackoverflow](http://stackoverflow.com/questions/tagged/spring-data-mongodb).
-
-If you are new to Spring as well as to Spring Data, look for information about [Spring projects](http://projects.spring.io/).
-
-
-## Quick Start
-
-### Maven configuration
-
-Add the Maven dependency:
-
-```xml
-<dependency>
-  <groupId>org.springframework.data</groupId>
-  <artifactId>spring-data-mongodb</artifactId>
-  <version>${version}.RELEASE</version>
-</dependency>
-```
-
-If you'd rather like the latest snapshots of the upcoming major version, use our Maven snapshot repository and declare the appropriate dependency version.
-
-```xml
-<dependency>
-  <groupId>org.springframework.data</groupId>
-  <artifactId>spring-data-mongodb</artifactId>
-  <version>${version}.BUILD-SNAPSHOT</version>
-</dependency>
-
-<repository>
-  <id>spring-libs-snapshot</id>
-  <name>Spring Snapshot Repository</name>
-  <url>http://repo.spring.io/libs-snapshot</url>
-</repository>
-```
-
-### MongoTemplate
-
-MongoTemplate is the central support class for Mongo database operations. It provides:
-
-* Basic POJO mapping support to and from BSON
-* Convenience methods to interact with the store (insert object, update objects) and MongoDB specific ones (geo-spatial operations, upserts, map-reduce etc.)
-* Connection affinity callback
-* Exception translation into Spring's [technology agnostic DAO exception hierarchy](http://docs.spring.io/spring/docs/current/spring-framework-reference/html/dao.html#dao-exceptions).
-
-### Spring Data repositories
-
-To simplify the creation of data repositories Spring Data MongoDB provides a generic repository programming model. It will automatically create a repository proxy for you that adds implementations of finder methods you specify on an interface.  
-
-For example, given a `Person` class with first and last name properties, a `PersonRepository` interface that can query for `Person` by last name and when the first name matches a like expression is shown below:
-
-```java
-public interface PersonRepository extends CrudRepository<Person, Long> {
-
-  List<Person> findByLastname(String lastname);
-
-  List<Person> findByFirstnameLike(String firstname);
-}
-```
-
-The queries issued on execution will be derived from the method name. Extending `CrudRepository` causes CRUD methods being pulled into the interface so that you can easily save and find single entities and collections of them.
-
-You can have Spring automatically create a proxy for the interface by using the following JavaConfig:
-
-```java
-@Configuration
-@EnableMongoRepositories
-class ApplicationConfig extends AbstractMongoConfiguration {
-
-  @Override
-  public Mongo mongo() throws Exception {
-    return new MongoClient();
-  }
-
-  @Override
-  protected String getDatabaseName() {
-    return "springdata";
-  }
-}
-```
-
-This sets up a connection to a local MongoDB instance and enables the detection of Spring Data repositories (through `@EnableMongoRepositories`). The same configuration would look like this in XML:
-
-```xml
-<bean id="template" class="org.springframework.data.mongodb.core.MongoTemplate">
-  <constructor-arg>
-    <bean class="com.mongodb.MongoClient">
-       <constructor-arg value="localhost" />
-       <constructor-arg value="27017" />
-    </bean>
-  </constructor-arg>
-  <constructor-arg value="database" />
-</bean>
-
-<mongo:repositories base-package="com.acme.repository" />
-```
-
-This will find the repository interface and register a proxy object in the container. You can use it as shown below:
-
-```java
-@Service
-public class MyService {
-
-  private final PersonRepository repository;
-
-  @Autowired
-  public MyService(PersonRepository repository) {
-    this.repository = repository;
-  }
-
-  public void doWork() {
-
-     repository.deleteAll();
-
-     Person person = new Person();
-     person.setFirstname("Oliver");
-     person.setLastname("Gierke");
-     person = repository.save(person);
-
-     List<Person> lastNameResults = repository.findByLastname("Gierke");
-     List<Person> firstNameResults = repository.findByFirstnameLike("Oli*");
- }
-}
-```
-
-## Contributing to Spring Data
-
-Here are some ways for you to get involved in the community:
-
-* Get involved with the Spring community on Stackoverflow and help out on the [spring-data-mongodb](http://stackoverflow.com/questions/tagged/spring-data-mongodb) tag by responding to questions and joining the debate.
-* Create [JIRA](https://jira.spring.io/browse/DATAMONGO) tickets for bugs and new features and comment and vote on the ones that you are interested in.  
-* Github is for social coding: if you want to write code, we encourage contributions through pull requests from [forks of this repository](http://help.github.com/forking/). If you want to contribute code this way, please reference a JIRA ticket as well covering the specific issue you are addressing.
-* Watch for upcoming articles on Spring by [subscribing](http://spring.io/blog) to spring.io.
-
-Before we accept a non-trivial patch or pull request we will need you to [sign the Contributor License Agreement](https://cla.pivotal.io/sign/spring). Signing the contributor’s agreement does not grant anyone commit rights to the main repository, but it does mean that we can accept your contributions, and you will get an author credit if we do. If you forget to do so, you'll be reminded when you submit a pull request. Active contributors might be asked to join the core team, and given the ability to merge pull requests.

ci/openjdk8-mongodb-4.0/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 9DA31620334BD75D9DCB49F368818C72E52529D4
+
+RUN echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.0 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.0.list
+
+RUN apt-get update
+
+RUN apt-get install -y mongodb-org=4.0.9 mongodb-org-server=4.0.9 mongodb-org-shell=4.0.9 mongodb-org-mongos=4.0.9 mongodb-org-tools=4.0.9
+
+RUN apt-get clean \
+ && rm -rf /var/lib/apt/lists/*

ci/openjdk8-mongodb-4.1/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 4B7C549A058F8B6B
+
+RUN echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.1 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.1.list
+
+RUN apt-get update
+
+RUN apt-get install -y mongodb-org-unstable=4.1.13 mongodb-org-unstable-server=4.1.13 mongodb-org-unstable-shell=4.1.13 mongodb-org-unstable-mongos=4.1.13 mongodb-org-unstable-tools=4.1.13
+
+RUN apt-get clean \
+ && rm -rf /var/lib/apt/lists/*

mvnw

@@ -0,0 +1,286 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven2 Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+  # TODO classpath?
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        wget "$jarUrl" -O "$wrapperJarPath"
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        curl -o "$wrapperJarPath" "$jarUrl"
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

mvnw.cmd

@@ -0,0 +1,161 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven2 Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing my setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
+FOR /F "tokens=1,2 delims==" %%A IN (%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties) DO (
+	IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B 
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    echo Found %WRAPPER_JAR%
+) else (
+    echo Couldn't find %WRAPPER_JAR%, downloading it ...
+	echo Downloading from: %DOWNLOAD_URL%
+    powershell -Command "(New-Object Net.WebClient).DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"
+    echo Finished downloading %WRAPPER_JAR%
+)
+@REM End of extension
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>2.0.15.BUILD-SNAPSHOT</version>
+	<version>2.1.10.RELEASE</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data MongoDB</name>
@@ -15,7 +15,7 @@
 	<parent>
 		<groupId>org.springframework.data.build</groupId>
 		<artifactId>spring-data-parent</artifactId>
-		<version>2.0.15.BUILD-SNAPSHOT</version>
+		<version>2.1.10.RELEASE</version>
 	</parent>
 
 	<modules>
@@ -27,9 +27,9 @@
 	<properties>
 		<project.type>multi</project.type>
 		<dist.id>spring-data-mongodb</dist.id>
-		<springdata.commons>2.0.15.BUILD-SNAPSHOT</springdata.commons>
-		<mongo>3.5.0</mongo>
-		<mongo.reactivestreams>1.6.0</mongo.reactivestreams>
+		<springdata.commons>2.1.10.RELEASE</springdata.commons>
+		<mongo>3.8.2</mongo>
+		<mongo.reactivestreams>1.9.2</mongo.reactivestreams>
 		<jmh.version>1.19</jmh.version>
 	</properties>
 
@@ -114,20 +114,6 @@
 	</developers>
 
 	<profiles>
-
-		<profile>
-			<id>release</id>
-			<build>
-				<plugins>
-					<plugin>
-						<groupId>org.jfrog.buildinfo</groupId>
-						<artifactId>artifactory-maven-plugin</artifactId>
-						<inherited>false</inherited>
-					</plugin>
-				</plugins>
-			</build>
-		</profile>
-
 		<profile>
 			<id>benchmarks</id>
 			<modules>
@@ -169,8 +155,8 @@
 
 	<repositories>
 		<repository>
-			<id>spring-libs-snapshot</id>
-			<url>https://repo.spring.io/libs-snapshot</url>
+			<id>spring-libs-release</id>
+			<url>https://repo.spring.io/libs-release</url>
 		</repository>
 	</repositories>
 
@@ -179,6 +165,11 @@
 			<id>spring-plugins-release</id>
 			<url>https://repo.spring.io/plugins-release</url>
 		</pluginRepository>
+		<pluginRepository>
+			<id>spring-libs-milestone</id>
+			<url>https://repo.spring.io/libs-milestone</url>
+		</pluginRepository>
+
 	</pluginRepositories>
 
 </project>

spring-data-mongodb-benchmarks/README.md

@@ -1,6 +1,6 @@
 # Benchmarks
 
-Benchmarks are based on [JMH](http://openjdk.java.net/projects/code-tools/jmh/).
+Benchmarks are based on [JMH](https://openjdk.java.net/projects/code-tools/jmh/).
 
 # Running Benchmarks
 

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.0.15.BUILD-SNAPSHOT</version>
+		<version>2.1.10.RELEASE</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

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

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.0.15.BUILD-SNAPSHOT</version>
+		<version>2.1.10.RELEASE</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -50,7 +50,7 @@
 		<dependency>
 			<groupId>org.springframework.data</groupId>
 			<artifactId>spring-data-mongodb</artifactId>
-			<version>2.0.15.BUILD-SNAPSHOT</version>
+			<version>2.1.10.RELEASE</version>
 		</dependency>
 
 		<!-- reactive -->

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

@@ -204,7 +204,7 @@ public class MongoChangeSetPersister implements ChangeSetPersister<Object> {
 
 	/**
 	 * Returns the collection the given entity type shall be persisted to.
-	 * 
+	 *
 	 * @param entityClass must not be {@literal null}.
 	 * @return
 	 */

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

@@ -39,7 +39,7 @@ import org.springframework.transaction.support.TransactionTemplate;
 
 /**
  * Integration tests for MongoDB cross-store persistence (mainly {@link MongoChangeSetPersister}).
- * 
+ *
  * @author Thomas Risberg
  * @author Oliver Gierke
  */

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

@@ -5,11 +5,11 @@
 	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 http://www.springframework.org/schema/data/mongo/spring-mongo.xsd
-		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
-		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
-		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
-		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
+	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/>
 

spring-data-mongodb-distribution/pom.xml

@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.0.15.BUILD-SNAPSHOT</version>
+		<version>2.1.10.RELEASE</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -28,10 +28,6 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-assembly-plugin</artifactId>
 			</plugin>
-			<plugin>
-				<groupId>org.codehaus.mojo</groupId>
-				<artifactId>wagon-maven-plugin</artifactId>
-			</plugin>
 			<plugin>
 				<groupId>org.asciidoctor</groupId>
 				<artifactId>asciidoctor-maven-plugin</artifactId>

spring-data-mongodb/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>2.0.15.BUILD-SNAPSHOT</version>
+		<version>2.1.10.RELEASE</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -20,6 +20,7 @@
 		<equalsverifier>1.7.8</equalsverifier>
 		<java-module-name>spring.data.mongodb</java-module-name>
 		<project.root>${basedir}/..</project.root>
+		<multithreadedtc>1.01</multithreadedtc>
 	</properties>
 
 	<dependencies>
@@ -245,6 +246,20 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>edu.umd.cs.mtc</groupId>
+			<artifactId>multithreadedtc</artifactId>
+			<version>${multithreadedtc}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>javax.transaction</groupId>
+			<artifactId>jta</artifactId>
+			<version>1.1</version>
+			<scope>test</scope>
+		</dependency>
+
 		<!-- Kotlin extension -->
 		<dependency>
 			<groupId>org.jetbrains.kotlin</groupId>
@@ -264,25 +279,12 @@
 			<version>${kotlin}</version>
 			<scope>test</scope>
 		</dependency>
+
 		<dependency>
-			<groupId>com.nhaarman</groupId>
-			<artifactId>mockito-kotlin</artifactId>
-			<version>1.5.0</version>
+			<groupId>io.mockk</groupId>
+			<artifactId>mockk</artifactId>
+			<version>${mockk}</version>
 			<scope>test</scope>
-			<exclusions>
-				<exclusion>
-					<groupId>org.jetbrains.kotlin</groupId>
-					<artifactId>kotlin-stdlib</artifactId>
-				</exclusion>
-				<exclusion>
-					<groupId>org.jetbrains.kotlin</groupId>
-					<artifactId>kotlin-reflect</artifactId>
-				</exclusion>
-				<exclusion>
-					<groupId>org.mockito</groupId>
-					<artifactId>mockito-core</artifactId>
-				</exclusion>
-			</exclusions>
 		</dependency>
 
 	</dependencies>

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

@@ -25,7 +25,7 @@ import com.mongodb.BulkWriteResult;
 
 /**
  * Is thrown when errors occur during bulk operations.
- * 
+ *
  * @author Tobias Trelle
  * @author Oliver Gierke
  * @since 1.9
@@ -39,7 +39,7 @@ public class BulkOperationException extends DataAccessException {
 
 	/**
 	 * Creates a new {@link BulkOperationException} with the given message and source {@link BulkWriteException}.
-	 * 
+	 *
 	 * @param message must not be {@literal null}.
 	 * @param source must not be {@literal null}.
 	 */

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

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018-2019 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;
+
+import org.springframework.dao.NonTransientDataAccessException;
+import org.springframework.lang.Nullable;
+
+/**
+ * {@link NonTransientDataAccessException} specific to MongoDB {@link com.mongodb.session.ClientSession} related data
+ * access failures such as reading data using an already closed session.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+public class ClientSessionException extends NonTransientDataAccessException {
+
+	/**
+	 * Constructor for {@link ClientSessionException}.
+	 *
+	 * @param msg the detail message. Must not be {@literal null}.
+	 */
+	public ClientSessionException(String msg) {
+		super(msg);
+	}
+
+	/**
+	 * Constructor for {@link ClientSessionException}.
+	 *
+	 * @param msg the detail message. Can be {@literal null}.
+	 * @param cause the root cause. Can be {@literal null}.
+	 */
+	public ClientSessionException(@Nullable String msg, @Nullable Throwable cause) {
+		super(msg, cause);
+	}
+}

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

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2017-2019 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;
+
+import java.util.Optional;
+
+import org.bson.codecs.Codec;
+import org.bson.codecs.configuration.CodecConfigurationException;
+import org.bson.codecs.configuration.CodecRegistry;
+import org.springframework.util.Assert;
+
+/**
+ * Provider interface to obtain {@link CodecRegistry} from the underlying MongoDB Java driver.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+@FunctionalInterface
+public interface CodecRegistryProvider {
+
+	/**
+	 * Get the underlying {@link CodecRegistry} used by the MongoDB Java driver.
+	 *
+	 * @return never {@literal null}.
+	 * @throws IllegalStateException if {@link CodecRegistry} cannot be obtained.
+	 */
+	CodecRegistry getCodecRegistry();
+
+	/**
+	 * Checks if a {@link Codec} is registered for a given type.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return true if {@link #getCodecRegistry()} holds a {@link Codec} for given type.
+	 * @throws IllegalStateException if {@link CodecRegistry} cannot be obtained.
+	 */
+	default boolean hasCodecFor(Class<?> type) {
+		return getCodecFor(type).isPresent();
+	}
+
+	/**
+	 * Get the {@link Codec} registered for the given {@literal type} or an {@link Optional#empty() empty Optional}
+	 * instead.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @param <T>
+	 * @return never {@literal null}.
+	 * @throws IllegalArgumentException if {@literal type} is {@literal null}.
+	 */
+	default <T> Optional<Codec<T>> getCodecFor(Class<T> type) {
+
+		Assert.notNull(type, "Type must not be null!");
+
+		try {
+			return Optional.of(getCodecRegistry().get(type));
+		} catch (CodecConfigurationException e) {
+			// ignore
+		}
+		return Optional.empty();
+	}
+}

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

@@ -23,7 +23,7 @@ import org.springframework.util.StringUtils;
  * <p/>
  * <p/>
  * Mainly intended for internal use within the framework.
- * 
+ *
  * @author Thomas Risberg
  * @since 1.0
  */
@@ -38,7 +38,7 @@ public abstract class MongoCollectionUtils {
 
 	/**
 	 * Obtains the collection name to use for the provided class
-	 * 
+	 *
 	 * @param entityClass The class to determine the preferred collection name for
 	 * @return The preferred collection name
 	 */

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

@@ -0,0 +1,240 @@
+/*
+ * Copyright 2018-2019 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;
+
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.support.ResourceHolderSynchronization;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.client.ClientSession;
+import com.mongodb.client.MongoDatabase;
+
+/**
+ * Helper class for managing a {@link MongoDatabase} instances via {@link MongoDbFactory}. Used for obtaining
+ * {@link ClientSession session bound} resources, such as {@link MongoDatabase} and
+ * {@link com.mongodb.client.MongoCollection} suitable for transactional usage.
+ * <p />
+ * <strong>Note:</strong> Intended for internal usage only.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @currentRead Shadow's Edge - Brent Weeks
+ * @since 2.1
+ */
+public class MongoDatabaseUtils {
+
+	/**
+	 * Obtain the default {@link MongoDatabase database} form the given {@link MongoDbFactory factory} using
+	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
+	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param factory the {@link MongoDbFactory} to get the {@link MongoDatabase} from.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static MongoDatabase getDatabase(MongoDbFactory factory) {
+		return doGetMongoDatabase(null, factory, SessionSynchronization.ON_ACTUAL_TRANSACTION);
+	}
+
+	/**
+	 * Obtain the default {@link MongoDatabase database} form the given {@link MongoDbFactory factory}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
+	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param factory the {@link MongoDbFactory} 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 MongoDatabase getDatabase(MongoDbFactory factory, SessionSynchronization sessionSynchronization) {
+		return doGetMongoDatabase(null, factory, sessionSynchronization);
+	}
+
+	/**
+	 * Obtain the {@link MongoDatabase database} with given name form the given {@link MongoDbFactory factory} using
+	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
+	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 *
+	 * @param dbName the name of the {@link MongoDatabase} to get.
+	 * @param factory the {@link MongoDbFactory} to get the {@link MongoDatabase} from.
+	 * @return the {@link MongoDatabase} that is potentially associated with a transactional {@link ClientSession}.
+	 */
+	public static MongoDatabase getDatabase(String dbName, MongoDbFactory factory) {
+		return doGetMongoDatabase(dbName, factory, SessionSynchronization.ON_ACTUAL_TRANSACTION);
+	}
+
+	/**
+	 * Obtain the {@link MongoDatabase database} with given name form the given {@link MongoDbFactory factory}.
+	 * <p />
+	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
+	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
+	 * 
+	 * @param dbName the name of the {@link MongoDatabase} to get.
+	 * @param factory the {@link MongoDbFactory} 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 MongoDatabase getDatabase(String dbName, MongoDbFactory factory,
+			SessionSynchronization sessionSynchronization) {
+		return doGetMongoDatabase(dbName, factory, sessionSynchronization);
+	}
+
+	private static MongoDatabase doGetMongoDatabase(@Nullable String dbName, MongoDbFactory factory,
+			SessionSynchronization sessionSynchronization) {
+
+		Assert.notNull(factory, "Factory must not be null!");
+
+		if (!TransactionSynchronizationManager.isSynchronizationActive()) {
+			return StringUtils.hasText(dbName) ? factory.getDb(dbName) : factory.getDb();
+		}
+
+		ClientSession session = doGetSession(factory, sessionSynchronization);
+
+		if (session == null) {
+			return StringUtils.hasText(dbName) ? factory.getDb(dbName) : factory.getDb();
+		}
+
+		MongoDbFactory factoryToUse = factory.withSession(session);
+		return StringUtils.hasText(dbName) ? factoryToUse.getDb(dbName) : factoryToUse.getDb();
+	}
+
+	/**
+	 * Check if the {@link MongoDbFactory} is actually bound to a {@link ClientSession} that has an active transaction, or
+	 * if a {@link TransactionSynchronization} has been registered for the {@link MongoDbFactory resource} and if the
+	 * associated {@link ClientSession} has an {@link ClientSession#hasActiveTransaction() active transaction}.
+	 *
+	 * @param dbFactory the resource to check transactions for. Must not be {@literal null}.
+	 * @return {@literal true} if the factory has an ongoing transaction.
+	 * @since 2.1.3
+	 */
+	public static boolean isTransactionActive(MongoDbFactory dbFactory) {
+
+		if (dbFactory.isTransactionActive()) {
+			return true;
+		}
+
+		MongoResourceHolder resourceHolder = (MongoResourceHolder) TransactionSynchronizationManager.getResource(dbFactory);
+		return resourceHolder != null && resourceHolder.hasActiveTransaction();
+	}
+
+	@Nullable
+	private static ClientSession doGetSession(MongoDbFactory dbFactory, SessionSynchronization sessionSynchronization) {
+
+		MongoResourceHolder resourceHolder = (MongoResourceHolder) TransactionSynchronizationManager.getResource(dbFactory);
+
+		// check for native MongoDB transaction
+		if (resourceHolder != null && (resourceHolder.hasSession() || resourceHolder.isSynchronizedWithTransaction())) {
+
+			if (!resourceHolder.hasSession()) {
+				resourceHolder.setSession(createClientSession(dbFactory));
+			}
+
+			return resourceHolder.getSession();
+		}
+
+		if (SessionSynchronization.ON_ACTUAL_TRANSACTION.equals(sessionSynchronization)) {
+			return null;
+		}
+
+		// init a non native MongoDB transaction by registering a MongoSessionSynchronization
+
+		resourceHolder = new MongoResourceHolder(createClientSession(dbFactory), dbFactory);
+		resourceHolder.getRequiredSession().startTransaction();
+
+		TransactionSynchronizationManager
+				.registerSynchronization(new MongoSessionSynchronization(resourceHolder, dbFactory));
+		resourceHolder.setSynchronizedWithTransaction(true);
+		TransactionSynchronizationManager.bindResource(dbFactory, resourceHolder);
+
+		return resourceHolder.getSession();
+	}
+
+	private static ClientSession createClientSession(MongoDbFactory 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 Jta or JDBC transaction.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	private static class MongoSessionSynchronization extends ResourceHolderSynchronization<MongoResourceHolder, Object> {
+
+		private final MongoResourceHolder resourceHolder;
+
+		MongoSessionSynchronization(MongoResourceHolder resourceHolder, MongoDbFactory dbFactory) {
+
+			super(resourceHolder, dbFactory);
+			this.resourceHolder = resourceHolder;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.ResourceHolderSynchronization#shouldReleaseBeforeCompletion()
+		 */
+		@Override
+		protected boolean shouldReleaseBeforeCompletion() {
+			return false;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.ResourceHolderSynchronization#processResourceAfterCommit(java.lang.Object)
+		 */
+		@Override
+		protected void processResourceAfterCommit(MongoResourceHolder resourceHolder) {
+
+			if (resourceHolder.hasActiveTransaction()) {
+				resourceHolder.getRequiredSession().commitTransaction();
+			}
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.ResourceHolderSynchronization#afterCompletion(int)
+		 */
+		@Override
+		public void afterCompletion(int status) {
+
+			if (status == TransactionSynchronization.STATUS_ROLLED_BACK && this.resourceHolder.hasActiveTransaction()) {
+				resourceHolder.getRequiredSession().abortTransaction();
+			}
+
+			super.afterCompletion(status);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.transaction.support.ResourceHolderSynchronization#releaseResource(java.lang.Object, java.lang.Object)
+		 */
+		@Override
+		protected void releaseResource(MongoResourceHolder resourceHolder, Object resourceKey) {
+
+			if (resourceHolder.hasActiveSession()) {
+				resourceHolder.getRequiredSession().close();
+			}
+		}
+	}
+}

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

@@ -15,11 +15,14 @@
  */
 package org.springframework.data.mongodb;
 
+import org.bson.codecs.configuration.CodecRegistry;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.core.MongoExceptionTranslator;
 
+import com.mongodb.ClientSessionOptions;
 import com.mongodb.DB;
+import com.mongodb.client.ClientSession;
 import com.mongodb.client.MongoDatabase;
 
 /**
@@ -27,8 +30,9 @@ import com.mongodb.client.MongoDatabase;
  *
  * @author Mark Pollack
  * @author Thomas Darimont
+ * @author Christoph Strobl
  */
-public interface MongoDbFactory {
+public interface MongoDbFactory extends CodecRegistryProvider, MongoSessionProvider {
 
 	/**
 	 * Creates a default {@link MongoDatabase} instance.
@@ -54,5 +58,65 @@ public interface MongoDbFactory {
 	 */
 	PersistenceExceptionTranslator getExceptionTranslator();
 
+	/**
+	 * Get the legacy database entry point. Please consider {@link #getDb()} instead.
+	 *
+	 * @return
+	 * @deprecated since 2.1, use {@link #getDb()}. This method will be removed with a future version as it works only
+	 *             with the legacy MongoDB driver.
+	 */
+	@Deprecated
 	DB getLegacyDb();
+
+	/**
+	 * Get the underlying {@link CodecRegistry} used by the MongoDB Java driver.
+	 *
+	 * @return never {@literal null}.
+	 */
+	@Override
+	default CodecRegistry getCodecRegistry() {
+		return getDb().getCodecRegistry();
+	}
+
+	/**
+	 * Obtain a {@link ClientSession} for given ClientSessionOptions.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	ClientSession getSession(ClientSessionOptions options);
+
+	/**
+	 * Obtain a {@link ClientSession} bound instance of {@link MongoDbFactory} returning {@link MongoDatabase} instances
+	 * that are aware and bound to a new session with given {@link ClientSessionOptions options}.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	default MongoDbFactory withSession(ClientSessionOptions options) {
+		return withSession(getSession(options));
+	}
+
+	/**
+	 * Obtain a {@link ClientSession} bound instance of {@link MongoDbFactory} returning {@link MongoDatabase} instances
+	 * that are aware and bound to the given session.
+	 *
+	 * @param session must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	MongoDbFactory withSession(ClientSession session);
+
+	/**
+	 * Returns if the given {@link MongoDbFactory} is bound to a {@link ClientSession} that has an
+	 * {@link ClientSession#hasActiveTransaction() active transaction}.
+	 *
+	 * @return {@literal true} if there's an active transaction, {@literal false} otherwise.
+	 * @since 2.1.3
+	 */
+	default boolean isTransactionActive() {
+		return false;
+	}
 }

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

@@ -0,0 +1,153 @@
+/*
+ * Copyright 2018-2019 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;
+
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.TransactionDefinition;
+import org.springframework.transaction.support.ResourceHolderSupport;
+
+import com.mongodb.client.ClientSession;
+
+/**
+ * MongoDB specific {@link ResourceHolderSupport resource holder}, wrapping a {@link ClientSession}.
+ * {@link MongoTransactionManager} binds instances of this class to the thread.
+ * <p />
+ * <strong>Note:</strong> Intended for internal usage only.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ * @see MongoTransactionManager
+ * @see org.springframework.data.mongodb.core.MongoTemplate
+ */
+class MongoResourceHolder extends ResourceHolderSupport {
+
+	private @Nullable ClientSession session;
+	private MongoDbFactory dbFactory;
+
+	/**
+	 * Create a new {@link MongoResourceHolder} for a given {@link ClientSession session}.
+	 *
+	 * @param session the associated {@link ClientSession}. Can be {@literal null}.
+	 * @param dbFactory the associated {@link MongoDbFactory}. must not be {@literal null}.
+	 */
+	MongoResourceHolder(@Nullable ClientSession session, MongoDbFactory dbFactory) {
+
+		this.session = session;
+		this.dbFactory = dbFactory;
+	}
+
+	/**
+	 * @return the associated {@link ClientSession}. Can be {@literal null}.
+	 */
+	@Nullable
+	ClientSession getSession() {
+		return session;
+	}
+
+	/**
+	 * @return the required associated {@link ClientSession}.
+	 * @throws IllegalStateException if no {@link ClientSession} is associated with this {@link MongoResourceHolder}.
+	 * @since 2.1.3
+	 */
+	ClientSession getRequiredSession() {
+
+		ClientSession session = getSession();
+
+		if (session == null) {
+			throw new IllegalStateException("No session available!");
+		}
+
+		return session;
+	}
+
+	/**
+	 * @return the associated {@link MongoDbFactory}.
+	 */
+	public MongoDbFactory getDbFactory() {
+		return dbFactory;
+	}
+
+	/**
+	 * Set the {@link ClientSession} to guard.
+	 *
+	 * @param session can be {@literal null}.
+	 */
+	public void setSession(@Nullable ClientSession session) {
+		this.session = session;
+	}
+
+	/**
+	 * Only set the timeout if it does not match the {@link TransactionDefinition#TIMEOUT_DEFAULT default timeout}.
+	 *
+	 * @param seconds
+	 */
+	void setTimeoutIfNotDefaulted(int seconds) {
+
+		if (seconds != TransactionDefinition.TIMEOUT_DEFAULT) {
+			setTimeoutInSeconds(seconds);
+		}
+	}
+
+	/**
+	 * @return {@literal true} if session is not {@literal null}.
+	 */
+	boolean hasSession() {
+		return session != null;
+	}
+
+	/**
+	 * @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.
+	 * @since 2.1.3
+	 * @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/MongoSessionProvider.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2018-2019 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;
+
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.client.ClientSession;
+
+/**
+ * A simple interface for obtaining a {@link ClientSession} to be consumed by
+ * {@link org.springframework.data.mongodb.core.MongoOperations} and MongoDB native operations that support causal
+ * consistency and transactions.
+ *
+ * @author Christoph Strobl
+ * @currentRead Shadow's Edge - Brent Weeks
+ * @since 2.1
+ */
+@FunctionalInterface
+public interface MongoSessionProvider {
+
+	/**
+	 * Obtain a {@link ClientSession} with with given options.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @throws org.springframework.dao.DataAccessException
+	 */
+	ClientSession getSession(ClientSessionOptions options);
+}

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

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018-2019 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;
+
+import org.springframework.lang.Nullable;
+
+/**
+ * A specific {@link ClientSessionException} related to issues with a transaction such as aborted or non existing
+ * transactions.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+public class MongoTransactionException extends ClientSessionException {
+
+	/**
+	 * Constructor for {@link MongoTransactionException}.
+	 *
+	 * @param msg the detail message. Must not be {@literal null}.
+	 */
+	public MongoTransactionException(String msg) {
+		super(msg);
+	}
+
+	/**
+	 * Constructor for {@link ClientSessionException}.
+	 *
+	 * @param msg the detail message. Can be {@literal null}.
+	 * @param cause the root cause. Can be {@literal null}.
+	 */
+	public MongoTransactionException(@Nullable String msg, @Nullable Throwable cause) {
+		super(msg, cause);
+	}
+}

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

@@ -0,0 +1,526 @@
+/*
+ * Copyright 2018-2019 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;
+
+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.support.AbstractPlatformTransactionManager;
+import org.springframework.transaction.support.DefaultTransactionStatus;
+import org.springframework.transaction.support.ResourceTransactionManager;
+import org.springframework.transaction.support.SmartTransactionObject;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+import org.springframework.transaction.support.TransactionSynchronizationUtils;
+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.client.ClientSession;
+
+/**
+ * A {@link org.springframework.transaction.PlatformTransactionManager} implementation that manages
+ * {@link ClientSession} based transactions for a single {@link MongoDbFactory}.
+ * <p />
+ * Binds a {@link ClientSession} from the specified {@link MongoDbFactory} to the thread.
+ * <p />
+ * {@link TransactionDefinition#isReadOnly() Readonly} transactions operate on a {@link ClientSession} and enable causal
+ * consistency, and also {@link ClientSession#startTransaction() start}, {@link ClientSession#commitTransaction()
+ * commit} or {@link ClientSession#abortTransaction() abort} a transaction.
+ * <p />
+ * Application code is required to retrieve the {@link com.mongodb.client.MongoDatabase} via
+ * {@link MongoDatabaseUtils#getDatabase(MongoDbFactory)} instead of a standard {@link MongoDbFactory#getDb()} call.
+ * Spring classes such as {@link org.springframework.data.mongodb.core.MongoTemplate} use this strategy implicitly.
+ * <p />
+ * By default failure of a {@literal commit} operation raises a {@link TransactionSystemException}. One may override
+ * {@link #doCommit(MongoTransactionObject)} 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
+ * @currentRead Shadow's Edge - Brent Weeks
+ * @since 2.1
+ * @see <a href="https://www.mongodb.com/transactions">MongoDB Transaction Documentation</a>
+ * @see MongoDatabaseUtils#getDatabase(MongoDbFactory, SessionSynchronization)
+ */
+public class MongoTransactionManager extends AbstractPlatformTransactionManager
+		implements ResourceTransactionManager, InitializingBean {
+
+	private @Nullable MongoDbFactory dbFactory;
+	private @Nullable TransactionOptions options;
+
+	/**
+	 * Create a new {@link MongoTransactionManager} for bean-style usage.
+	 * <p />
+	 * <strong>Note:</strong>The {@link MongoDbFactory db factory} has to be {@link #setDbFactory(MongoDbFactory) set}
+	 * before using the instance. Use this constructor to prepare a {@link MongoTransactionManager} 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 #setDbFactory(MongoDbFactory)
+	 * @see #setTransactionSynchronization(int)
+	 */
+	public MongoTransactionManager() {}
+
+	/**
+	 * Create a new {@link MongoTransactionManager} obtaining sessions from the given {@link MongoDbFactory}.
+	 *
+	 * @param dbFactory must not be {@literal null}.
+	 */
+	public MongoTransactionManager(MongoDbFactory dbFactory) {
+		this(dbFactory, null);
+	}
+
+	/**
+	 * Create a new {@link MongoTransactionManager} obtaining sessions from the given {@link MongoDbFactory} applying the
+	 * given {@link TransactionOptions options}, if present, when starting a new transaction.
+	 *
+	 * @param dbFactory must not be {@literal null}.
+	 * @param options can be {@literal null}.
+	 */
+	public MongoTransactionManager(MongoDbFactory dbFactory, @Nullable TransactionOptions options) {
+
+		Assert.notNull(dbFactory, "DbFactory must not be null!");
+
+		this.dbFactory = dbFactory;
+		this.options = options;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doGetTransaction()
+	 */
+	@Override
+	protected Object doGetTransaction() throws TransactionException {
+
+		MongoResourceHolder resourceHolder = (MongoResourceHolder) TransactionSynchronizationManager
+				.getResource(getRequiredDbFactory());
+		return new MongoTransactionObject(resourceHolder);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#isExistingTransaction(java.lang.Object)
+	 */
+	@Override
+	protected boolean isExistingTransaction(Object transaction) throws TransactionException {
+		return extractMongoTransaction(transaction).hasResourceHolder();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doBegin(java.lang.Object, org.springframework.transaction.TransactionDefinition)
+	 */
+	@Override
+	protected void doBegin(Object transaction, TransactionDefinition definition) throws TransactionException {
+
+		MongoTransactionObject mongoTransactionObject = extractMongoTransaction(transaction);
+
+		MongoResourceHolder resourceHolder = newResourceHolder(definition,
+				ClientSessionOptions.builder().causallyConsistent(true).build());
+		mongoTransactionObject.setResourceHolder(resourceHolder);
+
+		if (logger.isDebugEnabled()) {
+			logger
+					.debug(String.format("About to start transaction for session %s.", debugString(resourceHolder.getSession())));
+		}
+
+		try {
+			mongoTransactionObject.startTransaction(options);
+		} catch (MongoException ex) {
+			throw new TransactionSystemException(String.format("Could not start Mongo transaction for session %s.",
+					debugString(mongoTransactionObject.getSession())), ex);
+		}
+
+		if (logger.isDebugEnabled()) {
+			logger.debug(String.format("Started transaction for session %s.", debugString(resourceHolder.getSession())));
+		}
+
+		resourceHolder.setSynchronizedWithTransaction(true);
+		TransactionSynchronizationManager.bindResource(getRequiredDbFactory(), resourceHolder);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doSuspend(java.lang.Object)
+	 */
+	@Override
+	protected Object doSuspend(Object transaction) throws TransactionException {
+
+		MongoTransactionObject mongoTransactionObject = extractMongoTransaction(transaction);
+		mongoTransactionObject.setResourceHolder(null);
+
+		return TransactionSynchronizationManager.unbindResource(getRequiredDbFactory());
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doResume(java.lang.Object, java.lang.Object)
+	 */
+	@Override
+	protected void doResume(@Nullable Object transaction, Object suspendedResources) {
+		TransactionSynchronizationManager.bindResource(getRequiredDbFactory(), suspendedResources);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doCommit(org.springframework.transaction.support.DefaultTransactionStatus)
+	 */
+	@Override
+	protected final void doCommit(DefaultTransactionStatus status) throws TransactionException {
+
+		MongoTransactionObject mongoTransactionObject = extractMongoTransaction(status);
+
+		if (logger.isDebugEnabled()) {
+			logger.debug(String.format("About to commit transaction for session %s.",
+					debugString(mongoTransactionObject.getSession())));
+		}
+
+		try {
+			doCommit(mongoTransactionObject);
+		} catch (Exception ex) {
+
+			throw 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. <br />
+	 * <code>
+	 *     <pre>
+	 * int retries = 3;
+	 * do {
+	 *     try {
+	 *         transactionObject.commitTransaction();
+	 *         break;
+	 *     } catch (MongoException ex) {
+	 *         if (!ex.hasErrorLabel(MongoException.UNKNOWN_TRANSACTION_COMMIT_RESULT_LABEL)) {
+	 *             throw ex;
+	 *         }
+	 *     }
+	 *     Thread.sleep(500);
+	 * } while (--retries > 0);
+	 *     </pre>
+	 * </code>
+	 *
+	 * @param transactionObject never {@literal null}.
+	 * @throws Exception in case of transaction errors.
+	 */
+	protected void doCommit(MongoTransactionObject transactionObject) throws Exception {
+		transactionObject.commitTransaction();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doRollback(org.springframework.transaction.support.DefaultTransactionStatus)
+	 */
+	@Override
+	protected void doRollback(DefaultTransactionStatus status) throws TransactionException {
+
+		MongoTransactionObject mongoTransactionObject = extractMongoTransaction(status);
+
+		if (logger.isDebugEnabled()) {
+			logger.debug(String.format("About to abort transaction for session %s.",
+					debugString(mongoTransactionObject.getSession())));
+		}
+
+		try {
+			mongoTransactionObject.abortTransaction();
+		} catch (MongoException ex) {
+
+			throw new TransactionSystemException(String.format("Could not abort Mongo transaction for session %s.",
+					debugString(mongoTransactionObject.getSession())), ex);
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doSetRollbackOnly(org.springframework.transaction.support.DefaultTransactionStatus)
+	 */
+	@Override
+	protected void doSetRollbackOnly(DefaultTransactionStatus status) throws TransactionException {
+
+		MongoTransactionObject transactionObject = extractMongoTransaction(status);
+		transactionObject.getRequiredResourceHolder().setRollbackOnly();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doCleanupAfterCompletion(java.lang.Object)
+	 */
+	@Override
+	protected void doCleanupAfterCompletion(Object transaction) {
+
+		Assert.isInstanceOf(MongoTransactionObject.class, transaction,
+				() -> String.format("Expected to find a %s but it turned out to be %s.", MongoTransactionObject.class,
+						transaction.getClass()));
+
+		MongoTransactionObject mongoTransactionObject = (MongoTransactionObject) transaction;
+
+		// Remove the connection holder from the thread.
+		TransactionSynchronizationManager.unbindResource(getRequiredDbFactory());
+		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 MongoDbFactory} that this instance should manage transactions for.
+	 *
+	 * @param dbFactory must not be {@literal null}.
+	 */
+	public void setDbFactory(MongoDbFactory dbFactory) {
+
+		Assert.notNull(dbFactory, "DbFactory must not be null!");
+		this.dbFactory = dbFactory;
+	}
+
+	/**
+	 * 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 MongoDbFactory} that this instance manages transactions for.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public MongoDbFactory getDbFactory() {
+		return dbFactory;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.transaction.support.ResourceTransactionManager#getResourceFactory()
+	 */
+	@Override
+	public MongoDbFactory getResourceFactory() {
+		return getRequiredDbFactory();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+	 */
+	@Override
+	public void afterPropertiesSet() {
+		getRequiredDbFactory();
+	}
+
+	private MongoResourceHolder newResourceHolder(TransactionDefinition definition, ClientSessionOptions options) {
+
+		MongoDbFactory dbFactory = getResourceFactory();
+
+		MongoResourceHolder resourceHolder = new MongoResourceHolder(dbFactory.getSession(options), dbFactory);
+		resourceHolder.setTimeoutIfNotDefaulted(determineTimeout(definition));
+
+		return resourceHolder;
+	}
+
+	/**
+	 * @throws IllegalStateException if {@link #dbFactory} is {@literal null}.
+	 */
+	private MongoDbFactory getRequiredDbFactory() {
+
+		Assert.state(dbFactory != null,
+				"MongoTransactionManager operates upon a MongoDbFactory. Did you forget to provide one? It's required.");
+
+		return dbFactory;
+	}
+
+	private static MongoTransactionObject extractMongoTransaction(Object transaction) {
+
+		Assert.isInstanceOf(MongoTransactionObject.class, transaction,
+				() -> String.format("Expected to find a %s but it turned out to be %s.", MongoTransactionObject.class,
+						transaction.getClass()));
+
+		return (MongoTransactionObject) transaction;
+	}
+
+	private static MongoTransactionObject extractMongoTransaction(DefaultTransactionStatus status) {
+
+		Assert.isInstanceOf(MongoTransactionObject.class, status.getTransaction(),
+				() -> String.format("Expected to find a %s but it turned out to be %s.", MongoTransactionObject.class,
+						status.getTransaction().getClass()));
+
+		return (MongoTransactionObject) 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 MongoTransactionManager}.
+	 *
+	 * @author Christoph Strobl
+	 * @author Mark Paluch
+	 * @since 2.1
+	 * @see MongoResourceHolder
+	 */
+	protected static class MongoTransactionObject implements SmartTransactionObject {
+
+		private @Nullable MongoResourceHolder resourceHolder;
+
+		MongoTransactionObject(@Nullable MongoResourceHolder resourceHolder) {
+			this.resourceHolder = resourceHolder;
+		}
+
+		/**
+		 * Set the {@link MongoResourceHolder}.
+		 *
+		 * @param resourceHolder can be {@literal null}.
+		 */
+		void setResourceHolder(@Nullable MongoResourceHolder 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 void commitTransaction() {
+			getRequiredSession().commitTransaction();
+		}
+
+		/**
+		 * Rollback (abort) the transaction.
+		 */
+		public void abortTransaction() {
+			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 MongoResourceHolder getRequiredResourceHolder() {
+
+			Assert.state(resourceHolder != null, "MongoResourceHolder 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() {
+			TransactionSynchronizationUtils.triggerFlush();
+		}
+
+	}
+}

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

@@ -16,19 +16,25 @@
 
 package org.springframework.data.mongodb;
 
+import reactor.core.publisher.Mono;
+
+import org.bson.codecs.configuration.CodecRegistry;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.core.MongoExceptionTranslator;
 
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.reactivestreams.client.ClientSession;
 import com.mongodb.reactivestreams.client.MongoDatabase;
 
 /**
  * Interface for factories creating reactive {@link MongoDatabase} instances.
  *
  * @author Mark Paluch
+ * @author Christoph Strobl
  * @since 2.0
  */
-public interface ReactiveMongoDatabaseFactory {
+public interface ReactiveMongoDatabaseFactory extends CodecRegistryProvider {
 
 	/**
 	 * Creates a default {@link MongoDatabase} instance.
@@ -53,4 +59,33 @@ public interface ReactiveMongoDatabaseFactory {
 	 * @return will never be {@literal null}.
 	 */
 	PersistenceExceptionTranslator getExceptionTranslator();
+
+	/**
+	 * Get the underlying {@link CodecRegistry} used by the reactive MongoDB Java driver.
+	 *
+	 * @return never {@literal null}.
+	 */
+	@Override
+	default CodecRegistry getCodecRegistry() {
+		return getMongoDatabase().getCodecRegistry();
+	}
+
+	/**
+	 * Obtain a {@link Mono} emitting a {@link ClientSession} for given {@link ClientSessionOptions options}.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	Mono<ClientSession> getSession(ClientSessionOptions options);
+
+	/**
+	 * Obtain a {@link ClientSession} bound instance of {@link ReactiveMongoDatabaseFactory} returning
+	 * {@link MongoDatabase} instances that are aware and bound to the given session.
+	 *
+	 * @param session must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	ReactiveMongoDatabaseFactory withSession(ClientSession session);
 }

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

@@ -0,0 +1,215 @@
+/*
+ * Copyright 2018-2019 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;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.Optional;
+import java.util.function.BiFunction;
+
+import org.aopalliance.intercept.MethodInterceptor;
+import org.aopalliance.intercept.MethodInvocation;
+import org.springframework.core.MethodClassKey;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ConcurrentReferenceHashMap;
+import org.springframework.util.ReflectionUtils;
+
+import com.mongodb.WriteConcern;
+import com.mongodb.session.ClientSession;
+
+/**
+ * {@link MethodInterceptor} implementation looking up and invoking an alternative target method having
+ * {@link ClientSession} as its first argument. This allows seamless integration with the existing code base.
+ * <p />
+ * The {@link MethodInterceptor} is aware of methods on {@code MongoCollection} that my return new instances of itself
+ * like (eg. {@link com.mongodb.reactivestreams.client.MongoCollection#withWriteConcern(WriteConcern)} and decorate them
+ * if not already proxied.
+ *
+ * @param <D> Type of the actual Mongo Database.
+ * @param <C> Type of the actual Mongo Collection.
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+public class SessionAwareMethodInterceptor<D, C> implements MethodInterceptor {
+
+	private static final MethodCache METHOD_CACHE = new MethodCache();
+
+	private final ClientSession session;
+	private final ClientSessionOperator collectionDecorator;
+	private final ClientSessionOperator databaseDecorator;
+	private final Object target;
+	private final Class<?> targetType;
+	private final Class<?> collectionType;
+	private final Class<?> databaseType;
+	private final Class<? extends ClientSession> sessionType;
+
+	/**
+	 * Create a new SessionAwareMethodInterceptor for given target.
+	 *
+	 * @param session the {@link ClientSession} to be used on invocation.
+	 * @param target the original target object.
+	 * @param databaseType the MongoDB database type
+	 * @param databaseDecorator a {@link ClientSessionOperator} used to create the proxy for an imperative / reactive
+	 *          {@code MongoDatabase}.
+	 * @param collectionType the MongoDB collection type.
+	 * @param collectionDecorator a {@link ClientSessionOperator} used to create the proxy for an imperative / reactive
+	 *          {@code MongoCollection}.
+	 * @param <T> target object type.
+	 */
+	public <T> SessionAwareMethodInterceptor(ClientSession session, T target, Class<? extends ClientSession> sessionType,
+			Class<D> databaseType, ClientSessionOperator<D> databaseDecorator, Class<C> collectionType,
+			ClientSessionOperator<C> collectionDecorator) {
+
+		Assert.notNull(session, "ClientSession must not be null!");
+		Assert.notNull(target, "Target must not be null!");
+		Assert.notNull(sessionType, "SessionType must not be null!");
+		Assert.notNull(databaseType, "Database type must not be null!");
+		Assert.notNull(databaseDecorator, "Database ClientSessionOperator must not be null!");
+		Assert.notNull(collectionType, "Collection type must not be null!");
+		Assert.notNull(collectionDecorator, "Collection ClientSessionOperator must not be null!");
+
+		this.session = session;
+		this.target = target;
+		this.databaseType = ClassUtils.getUserClass(databaseType);
+		this.collectionType = ClassUtils.getUserClass(collectionType);
+		this.collectionDecorator = collectionDecorator;
+		this.databaseDecorator = databaseDecorator;
+
+		this.targetType = ClassUtils.isAssignable(databaseType, target.getClass()) ? databaseType : collectionType;
+		this.sessionType = sessionType;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.aopalliance.intercept.MethodInterceptor(org.aopalliance.intercept.MethodInvocation)
+	 */
+	@Nullable
+	@Override
+	public Object invoke(MethodInvocation methodInvocation) throws Throwable {
+
+		if (requiresDecoration(methodInvocation.getMethod())) {
+
+			Object target = methodInvocation.proceed();
+			if (target instanceof Proxy) {
+				return target;
+			}
+
+			return decorate(target);
+		}
+
+		if (!requiresSession(methodInvocation.getMethod())) {
+			return methodInvocation.proceed();
+		}
+
+		Optional<Method> targetMethod = METHOD_CACHE.lookup(methodInvocation.getMethod(), targetType, sessionType);
+
+		return !targetMethod.isPresent() ? methodInvocation.proceed()
+				: ReflectionUtils.invokeMethod(targetMethod.get(), target,
+						prependSessionToArguments(session, methodInvocation));
+	}
+
+	private boolean requiresDecoration(Method method) {
+
+		return ClassUtils.isAssignable(databaseType, method.getReturnType())
+				|| ClassUtils.isAssignable(collectionType, method.getReturnType());
+	}
+
+	@SuppressWarnings("unchecked")
+	protected Object decorate(Object target) {
+
+		return ClassUtils.isAssignable(databaseType, target.getClass()) ? databaseDecorator.apply(session, target)
+				: collectionDecorator.apply(session, target);
+	}
+
+	private static boolean requiresSession(Method method) {
+
+		if (method.getParameterCount() == 0
+				|| !ClassUtils.isAssignable(ClientSession.class, method.getParameterTypes()[0])) {
+			return true;
+		}
+
+		return false;
+	}
+
+	private static Object[] prependSessionToArguments(ClientSession session, MethodInvocation invocation) {
+
+		Object[] args = new Object[invocation.getArguments().length + 1];
+
+		args[0] = session;
+		System.arraycopy(invocation.getArguments(), 0, args, 1, invocation.getArguments().length);
+
+		return args;
+	}
+
+	/**
+	 * Simple {@link Method} to {@link Method} caching facility for {@link ClientSession} overloaded targets.
+	 *
+	 * @since 2.1
+	 * @author Christoph Strobl
+	 */
+	static class MethodCache {
+
+		private final ConcurrentReferenceHashMap<MethodClassKey, Optional<Method>> cache = new ConcurrentReferenceHashMap<>();
+
+		/**
+		 * Lookup the target {@link Method}.
+		 *
+		 * @param method
+		 * @param targetClass
+		 * @return
+		 */
+		Optional<Method> lookup(Method method, Class<?> targetClass, Class<? extends ClientSession> sessionType) {
+
+			return cache.computeIfAbsent(new MethodClassKey(method, targetClass),
+					val -> Optional.ofNullable(findTargetWithSession(method, targetClass, sessionType)));
+		}
+
+		@Nullable
+		private Method findTargetWithSession(Method sourceMethod, Class<?> targetType,
+				Class<? extends ClientSession> sessionType) {
+
+			Class<?>[] argTypes = sourceMethod.getParameterTypes();
+			Class<?>[] args = new Class<?>[argTypes.length + 1];
+			args[0] = sessionType;
+			System.arraycopy(argTypes, 0, args, 1, argTypes.length);
+
+			return ReflectionUtils.findMethod(targetType, sourceMethod.getName(), args);
+		}
+
+		/**
+		 * Check whether the cache contains an entry for {@link Method} and {@link Class}.
+		 *
+		 * @param method
+		 * @param targetClass
+		 * @return
+		 */
+		boolean contains(Method method, Class<?> targetClass) {
+			return cache.containsKey(new MethodClassKey(method, targetClass));
+		}
+	}
+
+	/**
+	 * Represents an operation upon two operands of the same type, producing a result of the same type as the operands
+	 * accepting {@link ClientSession}. This is a specialization of {@link BiFunction} for the case where the operands and
+	 * the result are all of the same type.
+	 *
+	 * @param <T> the type of the operands and result of the operator
+	 */
+	public interface ClientSessionOperator<T> extends BiFunction<ClientSession, T, T> {}
+}

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2018-2019 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;
+
+/**
+ * {@link SessionSynchronization} is used along with {@link org.springframework.data.mongodb.core.MongoTemplate} to
+ * define in which type of transactions to participate if any.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+public enum SessionSynchronization {
+
+	/**
+	 * Synchronize with any transaction even with empty transactions and initiate a MongoDB transaction when doing so by
+	 * registering a MongoDB specific {@link org.springframework.transaction.support.ResourceHolderSynchronization}.
+	 */
+	ALWAYS,
+
+	/**
+	 * Synchronize with native MongoDB transactions initiated via {@link MongoTransactionManager}.
+	 */
+	ON_ACTUAL_TRANSACTION;
+}

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

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2018-2019 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.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.mongodb.MongoDbFactory;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.SimpleMongoClientDbFactory;
+import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
+import org.springframework.data.mongodb.core.convert.DbRefResolver;
+import org.springframework.data.mongodb.core.convert.DefaultDbRefResolver;
+import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
+import org.springframework.data.mongodb.core.mapping.Document;
+import org.springframework.lang.Nullable;
+
+import com.mongodb.client.MongoClient;
+
+/**
+ * Base class for Spring Data MongoDB configuration using JavaConfig with {@link com.mongodb.client.MongoClient}.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ * @see MongoConfigurationSupport
+ * @see AbstractMongoConfiguration
+ */
+@Configuration
+public abstract class AbstractMongoClientConfiguration extends MongoConfigurationSupport {
+
+	/**
+	 * Return the {@link MongoClient} instance to connect to. Annotate with {@link Bean} in case you want to expose a
+	 * {@link MongoClient} instance to the {@link org.springframework.context.ApplicationContext}.
+	 *
+	 * @return
+	 */
+	public abstract MongoClient mongoClient();
+
+	/**
+	 * Creates a {@link MongoTemplate}.
+	 *
+	 * @return
+	 */
+	@Bean
+	public MongoTemplate mongoTemplate() throws Exception {
+		return new MongoTemplate(mongoDbFactory(), mappingMongoConverter());
+	}
+
+	/**
+	 * Creates a {@link SimpleMongoDbFactory} to be used by the {@link MongoTemplate}. Will use the {@link MongoClient}
+	 * instance configured in {@link #mongoClient()}.
+	 *
+	 * @see #mongoClient()
+	 * @see #mongoTemplate()
+	 * @return
+	 */
+	@Bean
+	public MongoDbFactory mongoDbFactory() {
+		return new SimpleMongoClientDbFactory(mongoClient(), getDatabaseName());
+	}
+
+	/**
+	 * Return the base package to scan for mapped {@link Document}s. Will return the package name of the configuration
+	 * class' (the concrete class, not this one here) by default. So if you have a {@code com.acme.AppConfig} extending
+	 * {@link AbstractMongoClientConfiguration} the base package will be considered {@code com.acme} unless the method is
+	 * overridden to implement alternate behavior.
+	 *
+	 * @return the base package to scan for mapped {@link Document} classes or {@literal null} to not enable scanning for
+	 *         entities.
+	 * @deprecated use {@link #getMappingBasePackages()} instead.
+	 */
+	@Deprecated
+	@Nullable
+	protected String getMappingBasePackage() {
+
+		Package mappingBasePackage = getClass().getPackage();
+		return mappingBasePackage == null ? null : mappingBasePackage.getName();
+	}
+
+	/**
+	 * Creates a {@link MappingMongoConverter} using the configured {@link #mongoDbFactory()} and
+	 * {@link #mongoMappingContext()}. Will get {@link #customConversions()} applied.
+	 *
+	 * @see #customConversions()
+	 * @see #mongoMappingContext()
+	 * @see #mongoDbFactory()
+	 * @return
+	 * @throws Exception
+	 */
+	@Bean
+	public MappingMongoConverter mappingMongoConverter() throws Exception {
+
+		DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory());
+		MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext());
+		converter.setCustomConversions(customConversions());
+
+		return converter;
+	}
+}

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

@@ -29,7 +29,10 @@ import org.springframework.lang.Nullable;
 import com.mongodb.MongoClient;
 
 /**
- * Base class for Spring Data MongoDB configuration using JavaConfig.
+ * Base class for Spring Data MongoDB configuration using JavaConfig with {@link com.mongodb.MongoClient}.
+ * <p />
+ * <strong>INFO:</strong>In case you want to use {@link com.mongodb.client.MongoClients} for configuration please refer
+ * to {@link AbstractMongoClientConfiguration}.
  *
  * @author Mark Pollack
  * @author Oliver Gierke
@@ -38,10 +41,10 @@ import com.mongodb.MongoClient;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @see MongoConfigurationSupport
+ * @see AbstractMongoClientConfiguration
  */
 @Configuration
-public abstract class
-AbstractMongoConfiguration extends MongoConfigurationSupport {
+public abstract class AbstractMongoConfiguration extends MongoConfigurationSupport {
 
 	/**
 	 * Return the {@link MongoClient} instance to connect to. Annotate with {@link Bean} in case you want to expose a
@@ -63,7 +66,7 @@ AbstractMongoConfiguration extends MongoConfigurationSupport {
 
 	/**
 	 * Creates a {@link SimpleMongoDbFactory} to be used by the {@link MongoTemplate}. Will use the {@link MongoClient}
-	 * instance configured in {@link #mongo()}.
+	 * instance configured in {@link #mongoClient()}.
 	 *
 	 * @see #mongoClient()
 	 * @see #mongoTemplate()
@@ -111,4 +114,5 @@ AbstractMongoConfiguration extends MongoConfigurationSupport {
 
 		return converter;
 	}
+
 }

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

@@ -22,6 +22,7 @@ import org.springframework.data.mongodb.core.ReactiveMongoOperations;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
+import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
 
 import com.mongodb.reactivestreams.client.MongoClient;
 
@@ -80,8 +81,7 @@ public abstract class AbstractReactiveMongoConfiguration extends MongoConfigurat
 	@Bean
 	public MappingMongoConverter mappingMongoConverter() throws Exception {
 
-		MappingMongoConverter converter = new MappingMongoConverter(ReactiveMongoTemplate.NO_OP_REF_RESOLVER,
-				mongoMappingContext());
+		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mongoMappingContext());
 		converter.setCustomConversions(customConversions());
 
 		return converter;

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

@@ -17,7 +17,7 @@ package org.springframework.data.mongodb.config;
 
 /**
  * Constants to declare bean names used by the namespace configuration.
- * 
+ *
  * @author Jon Brisbin
  * @author Oliver Gierke
  * @author Martin Baumgartner

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

@@ -28,7 +28,7 @@ import org.springframework.data.domain.AuditorAware;
 
 /**
  * Annotation to enable auditing in MongoDB via annotation configuration.
- * 
+ *
  * @author Thomas Darimont
  * @author Oliver Gierke
  */
@@ -41,21 +41,21 @@ public @interface EnableMongoAuditing {
 
 	/**
 	 * Configures the {@link AuditorAware} bean to be used to lookup the current principal.
-	 * 
+	 *
 	 * @return
 	 */
 	String auditorAwareRef() default "";
 
 	/**
 	 * Configures whether the creation and modification dates are set. Defaults to {@literal true}.
-	 * 
+	 *
 	 * @return
 	 */
 	boolean setDates() default true;
 
 	/**
 	 * Configures whether the entity shall be marked as modified on creation. Defaults to {@literal true}.
-	 * 
+	 *
 	 * @return
 	 */
 	boolean modifyOnCreate() default true;
@@ -63,7 +63,7 @@ public @interface EnableMongoAuditing {
 	/**
 	 * Configures a {@link DateTimeProvider} bean name that allows customizing the {@link org.joda.time.DateTime} to be
 	 * used for setting creation and modification dates.
-	 * 
+	 *
 	 * @return
 	 */
 	String dateTimeProviderRef() default "";

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

@@ -21,7 +21,7 @@ import org.springframework.data.web.config.SpringDataJacksonModules;
 
 /**
  * Configuration class to expose {@link GeoJsonModule} as a Spring bean.
- * 
+ *
  * @author Oliver Gierke
  * @author Jens Schauder
  */

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

@@ -29,7 +29,7 @@ import org.w3c.dom.Element;
 
 /**
  * {@link BeanDefinitionParser} to parse {@code gridFsTemplate} elements into {@link BeanDefinition}s.
- * 
+ *
  * @author Martin Baumgartner
  */
 class GridFsTemplateParser extends AbstractBeanDefinitionParser {

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

@@ -33,12 +33,12 @@ import org.w3c.dom.Element;
 /**
  * {@link BeanDefinitionParser} to register a {@link AuditingEventListener} to transparently set auditing information on
  * an entity.
- * 
+ *
  * @author Oliver Gierke
  */
 public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser#getBeanClass(org.w3c.dom.Element)
 	 */
@@ -47,7 +47,7 @@ public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinit
 		return AuditingEventListener.class;
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#shouldGenerateId()
 	 */
@@ -56,7 +56,7 @@ public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinit
 		return true;
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser#doParse(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext, org.springframework.beans.factory.support.BeanDefinitionBuilder)
 	 */

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

@@ -37,13 +37,13 @@ import org.springframework.util.Assert;
 
 /**
  * {@link ImportBeanDefinitionRegistrar} to enable {@link EnableMongoAuditing} annotation.
- * 
+ *
  * @author Thomas Darimont
  * @author Oliver Gierke
  */
 class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAnnotation()
 	 */
@@ -52,7 +52,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		return EnableMongoAuditing.class;
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditingHandlerBeanName()
 	 */
@@ -61,7 +61,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		return "mongoAuditingHandler";
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#registerBeanDefinitions(org.springframework.core.type.AnnotationMetadata, org.springframework.beans.factory.support.BeanDefinitionRegistry)
 	 */
@@ -74,7 +74,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		super.registerBeanDefinitions(annotationMetadata, registry);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditHandlerBeanDefinitionBuilder(org.springframework.data.auditing.config.AuditingConfiguration)
 	 */
@@ -92,7 +92,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		return configureDefaultAuditHandlerAttributes(configuration, builder);
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#registerAuditListener(org.springframework.beans.factory.config.BeanDefinition, org.springframework.beans.factory.support.BeanDefinitionRegistry)
 	 */
@@ -125,14 +125,14 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
 		/**
 		 * Creates a new {@link MongoMappingContextLookup} for the given {@link MappingMongoConverter}.
-		 * 
+		 *
 		 * @param converter must not be {@literal null}.
 		 */
 		public MongoMappingContextLookup(MappingMongoConverter converter) {
 			this.converter = converter;
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.beans.factory.FactoryBean#getObject()
 		 */
@@ -141,7 +141,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 			return converter.getMappingContext();
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.beans.factory.FactoryBean#getObjectType()
 		 */
@@ -150,7 +150,7 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 			return MappingContext.class;
 		}
 
-		/* 
+		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.beans.factory.FactoryBean#isSingleton()
 		 */

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

@@ -29,13 +29,13 @@ import org.w3c.dom.Element;
 
 /**
  * Parser for {@code mongo-client} definitions.
- * 
+ *
  * @author Christoph Strobl
  * @since 1.7
  */
 public class MongoClientParser implements BeanDefinitionParser {
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.BeanDefinitionParser#parse(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
 	 */

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

@@ -17,7 +17,6 @@ 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;
@@ -27,7 +26,6 @@ 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;
@@ -102,20 +100,12 @@ public class MongoCredentialPropertyEditor extends PropertyEditorSupport {
 						verifyDatabasePresent(database);
 						credentials.add(MongoCredential.createScramSha1Credential(userNameAndPassword[0], database,
 								userNameAndPassword[1].toCharArray()));
-					} else if ("SCRAM-SHA-256".equals(authMechanism)) {
-
-						Method createScramSha256Credential = ReflectionUtils.findMethod(MongoCredential.class,
-								"createScramSha256Credential", String.class, String.class, char[].class);
-
-						if (createScramSha256Credential == null) {
-							throw new IllegalArgumentException(
-									"SCRAM-SHA-256 auth mechanism is available as of MongoDB 4 and MongoDB Java Driver 3.8! Please make sure to use at least those versions.");
-						}
+					} else if (MongoCredential.SCRAM_SHA_256_MECHANISM.equals(authMechanism)) {
 
 						verifyUsernameAndPasswordPresent(userNameAndPassword);
 						verifyDatabasePresent(database);
-						credentials.add(MongoCredential.class.cast(ReflectionUtils.invokeMethod(createScramSha256Credential, null,
-								userNameAndPassword[0], database, userNameAndPassword[1].toCharArray())));
+						credentials.add(MongoCredential.createScramSha256Credential(userNameAndPassword[0], database,
+								userNameAndPassword[1].toCharArray()));
 					} else {
 						throw new IllegalArgumentException(
 								String.format("Cannot create MongoCredentials for unknown auth mechanism '%s'!", authMechanism));

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

@@ -19,7 +19,7 @@ import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
 
 /**
  * {@link org.springframework.beans.factory.xml.NamespaceHandler} for Mongo DB configuration.
- * 
+ *
  * @author Oliver Gierke
  * @author Martin Baumgartner
  * @author Christoph Strobl

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

@@ -30,7 +30,7 @@ import org.w3c.dom.Element;
 
 /**
  * Utility methods for {@link BeanDefinitionParser} implementations for MongoDB.
- * 
+ *
  * @author Mark Pollack
  * @author Oliver Gierke
  * @author Thomas Darimont
@@ -43,7 +43,7 @@ abstract class MongoParsingUtils {
 
 	/**
 	 * Parses the mongo replica-set element.
-	 * 
+	 *
 	 * @param parserContext the parser context
 	 * @param element the mongo element
 	 * @param mongoBuilder the bean definition builder to populate
@@ -56,7 +56,7 @@ abstract class MongoParsingUtils {
 	/**
 	 * Parses the {@code mongo:client-options} sub-element. Populates the given attribute factory with the proper
 	 * attributes.
-	 * 
+	 *
 	 * @param element must not be {@literal null}.
 	 * @param mongoClientBuilder must not be {@literal null}.
 	 * @return
@@ -102,7 +102,7 @@ abstract class MongoParsingUtils {
 	/**
 	 * Returns the {@link BeanDefinitionBuilder} to build a {@link BeanDefinition} for a
 	 * {@link WriteConcernPropertyEditor}.
-	 * 
+	 *
 	 * @return
 	 */
 	static BeanDefinitionBuilder getWriteConcernPropertyEditorBuilder() {
@@ -135,7 +135,7 @@ abstract class MongoParsingUtils {
 	/**
 	 * Returns the {@link BeanDefinitionBuilder} to build a {@link BeanDefinition} for a
 	 * {@link ReadPreferencePropertyEditor}.
-	 * 
+	 *
 	 * @return
 	 * @since 1.7
 	 */
@@ -153,7 +153,7 @@ abstract class MongoParsingUtils {
 	/**
 	 * Returns the {@link BeanDefinitionBuilder} to build a {@link BeanDefinition} for a
 	 * {@link MongoCredentialPropertyEditor}.
-	 * 
+	 *
 	 * @return
 	 * @since 1.7
 	 */

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

@@ -33,13 +33,13 @@ import org.w3c.dom.Element;
 
 /**
  * {@link BeanDefinitionParser} to parse {@code template} elements into {@link BeanDefinition}s.
- * 
+ *
  * @author Martin Baumgartner
  * @author Oliver Gierke
  */
 class MongoTemplateParser extends AbstractBeanDefinitionParser {
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#resolveId(org.w3c.dom.Element, org.springframework.beans.factory.support.AbstractBeanDefinition, org.springframework.beans.factory.xml.ParserContext)
 	 */

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

@@ -23,7 +23,7 @@ import com.mongodb.ReadPreference;
 
 /**
  * Parse a {@link String} to a {@link ReadPreference}.
- * 
+ *
  * @author Christoph Strobl
  * @since 1.7
  */

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

@@ -21,12 +21,12 @@ import com.mongodb.WriteConcern;
 
 /**
  * Converter to create {@link WriteConcern} instances from String representations.
- * 
+ *
  * @author Oliver Gierke
  */
 public class StringToWriteConcernConverter implements Converter<String, WriteConcern> {
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
 	 */

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

@@ -27,7 +27,7 @@ import com.mongodb.WriteConcern;
  * {@link WriteConcern#valueOf(String)}, use the well known {@link WriteConcern} value, otherwise pass the string as is
  * to the constructor of the write concern. There is no support for other constructor signatures when parsing from a
  * string value.
- * 
+ *
  * @author Mark Pollack
  * @author Christoph Strobl
  */

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

@@ -17,6 +17,8 @@ package org.springframework.data.mongodb.core;
 
 import lombok.AllArgsConstructor;
 
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
@@ -24,13 +26,19 @@ import java.util.stream.Collectors;
 import org.bson.Document;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
+import org.springframework.data.mongodb.core.aggregation.AggregationOperation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
+import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
+import org.springframework.data.mongodb.core.aggregation.CountOperation;
 import org.springframework.data.mongodb.core.aggregation.TypeBasedAggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.TypedAggregation;
 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.data.mongodb.core.query.CriteriaDefinition;
+import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -39,7 +47,7 @@ import org.springframework.util.ObjectUtils;
  *
  * @author Christoph Strobl
  * @author Mark Paluch
- * @since 2.0.8
+ * @since 2.1
  */
 @AllArgsConstructor
 class AggregationUtil {
@@ -78,16 +86,13 @@ class AggregationUtil {
 	 * @param context
 	 * @return
 	 */
-	Document createPipeline(String collectionName, Aggregation aggregation, AggregationOperationContext context) {
+	List<Document> createPipeline(Aggregation aggregation, AggregationOperationContext context) {
 
 		if (!ObjectUtils.nullSafeEquals(context, Aggregation.DEFAULT_CONTEXT)) {
-			return aggregation.toDocument(collectionName, context);
+			return aggregation.toPipeline(context);
 		}
 
-		Document command = aggregation.toDocument(collectionName, context);
-		command.put("pipeline", mapAggregationPipeline(command.get("pipeline", List.class)));
-
-		return command;
+		return mapAggregationPipeline(aggregation.toPipeline(context));
 	}
 
 	/**
@@ -110,6 +115,53 @@ class AggregationUtil {
 		return command;
 	}
 
+	/**
+	 * Create a {@code $count} aggregation for {@link Query} and optionally a {@link Class entity class}.
+	 *
+	 * @param query must not be {@literal null}.
+	 * @param entityClass can be {@literal null} if the {@link Query} object is empty.
+	 * @return the {@link Aggregation} pipeline definition to run a {@code $count} aggregation.
+	 */
+	Aggregation createCountAggregation(Query query, @Nullable Class<?> entityClass) {
+
+		List<AggregationOperation> pipeline = computeCountAggregationPipeline(query, entityClass);
+
+		Aggregation aggregation = entityClass != null ? Aggregation.newAggregation(entityClass, pipeline)
+				: Aggregation.newAggregation(pipeline);
+		aggregation.withOptions(AggregationOptions.builder().collation(query.getCollation().orElse(null)).build());
+
+		return aggregation;
+	}
+
+	private List<AggregationOperation> computeCountAggregationPipeline(Query query, @Nullable Class<?> entityType) {
+
+		CountOperation count = Aggregation.count().as("totalEntityCount");
+		if (query.getQueryObject().isEmpty()) {
+			return Collections.singletonList(count);
+		}
+
+		Assert.notNull(entityType, "Entity type must not be null!");
+
+		Document mappedQuery = queryMapper.getMappedObject(query.getQueryObject(),
+				mappingContext.getPersistentEntity(entityType));
+
+		CriteriaDefinition criteria = new CriteriaDefinition() {
+
+			@Override
+			public Document getCriteriaObject() {
+				return mappedQuery;
+			}
+
+			@Nullable
+			@Override
+			public String getKey() {
+				return null;
+			}
+		};
+
+		return Arrays.asList(Aggregation.match(criteria), count);
+	}
+
 	private List<Document> mapAggregationPipeline(List<Document> pipeline) {
 
 		return pipeline.stream().map(val -> queryMapper.getMappedObject(val, Optional.empty()))

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

@@ -0,0 +1,190 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.EqualsAndHashCode;
+
+import java.time.Instant;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+
+import org.bson.BsonValue;
+import org.bson.Document;
+import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.messaging.Message;
+import org.springframework.lang.Nullable;
+import org.springframework.util.ClassUtils;
+
+import com.mongodb.client.model.changestream.ChangeStreamDocument;
+import com.mongodb.client.model.changestream.OperationType;
+
+/**
+ * {@link Message} implementation specific to MongoDB <a href="https://docs.mongodb.com/manual/changeStreams/">Change
+ * Streams</a>.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+@EqualsAndHashCode
+public class ChangeStreamEvent<T> {
+
+	@SuppressWarnings("rawtypes") //
+	private static final AtomicReferenceFieldUpdater<ChangeStreamEvent, Object> CONVERTED_UPDATER = AtomicReferenceFieldUpdater
+			.newUpdater(ChangeStreamEvent.class, Object.class, "converted");
+
+	private final @Nullable ChangeStreamDocument<Document> raw;
+
+	private final Class<T> targetType;
+	private final MongoConverter converter;
+
+	// accessed through CONVERTED_UPDATER.
+	private volatile @Nullable T converted;
+
+	/**
+	 * @param raw can be {@literal null}.
+	 * @param targetType must not be {@literal null}.
+	 * @param converter must not be {@literal null}.
+	 */
+	public ChangeStreamEvent(@Nullable ChangeStreamDocument<Document> raw, Class<T> targetType,
+			MongoConverter converter) {
+
+		this.raw = raw;
+		this.targetType = targetType;
+		this.converter = converter;
+	}
+
+	/**
+	 * Get the raw {@link ChangeStreamDocument} as emitted by the driver.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public ChangeStreamDocument<Document> getRaw() {
+		return raw;
+	}
+
+	/**
+	 * Get the {@link ChangeStreamDocument#getClusterTime() cluster time} as {@link Instant} the event was emitted at.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public Instant getTimestamp() {
+
+		return raw != null && raw.getClusterTime() != null
+				? converter.getConversionService().convert(raw.getClusterTime(), Instant.class) : null;
+	}
+
+	/**
+	 * Get the {@link ChangeStreamDocument#getResumeToken() resume token} for this event.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public BsonValue getResumeToken() {
+		return raw != null ? raw.getResumeToken() : null;
+	}
+
+	/**
+	 * Get the {@link ChangeStreamDocument#getOperationType() operation type} for this event.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public OperationType getOperationType() {
+		return raw != null ? raw.getOperationType() : null;
+	}
+
+	/**
+	 * Get the database name the event was originated at.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public String getDatabaseName() {
+		return raw != null ? raw.getNamespace().getDatabaseName() : null;
+	}
+
+	/**
+	 * Get the collection name the event was originated at.
+	 *
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public String getCollectionName() {
+		return raw != null ? raw.getNamespace().getCollectionName() : null;
+	}
+
+	/**
+	 * Get the potentially converted {@link ChangeStreamDocument#getFullDocument()}.
+	 *
+	 * @return {@literal null} when {@link #getRaw()} or {@link ChangeStreamDocument#getFullDocument()} is
+	 *         {@literal null}.
+	 */
+	@Nullable
+	public T getBody() {
+
+		if (raw == null) {
+			return null;
+		}
+
+		Document fullDocument = raw.getFullDocument();
+
+		if (fullDocument == null) {
+			return targetType.cast(fullDocument);
+		}
+
+		return getConverted(fullDocument);
+	}
+
+	@SuppressWarnings("unchecked")
+	private T getConverted(Document fullDocument) {
+		return (T) doGetConverted(fullDocument);
+	}
+
+	private Object doGetConverted(Document fullDocument) {
+
+		Object result = CONVERTED_UPDATER.get(this);
+
+		if (result != null) {
+			return result;
+		}
+
+		if (ClassUtils.isAssignable(Document.class, fullDocument.getClass())) {
+
+			result = converter.read(targetType, fullDocument);
+			return CONVERTED_UPDATER.compareAndSet(this, null, result) ? result : CONVERTED_UPDATER.get(this);
+		}
+
+		if (converter.getConversionService().canConvert(fullDocument.getClass(), targetType)) {
+
+			result = converter.getConversionService().convert(fullDocument, targetType);
+			return CONVERTED_UPDATER.compareAndSet(this, null, result) ? result : CONVERTED_UPDATER.get(this);
+		}
+
+		throw new IllegalArgumentException(String.format("No converter found capable of converting %s to %s",
+				fullDocument.getClass(), targetType));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return "ChangeStreamEvent {" + "raw=" + raw + ", targetType=" + targetType + '}';
+	}
+}

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

@@ -0,0 +1,243 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.EqualsAndHashCode;
+
+import java.time.Instant;
+import java.util.Arrays;
+import java.util.Optional;
+
+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 com.mongodb.client.model.changestream.ChangeStreamDocument;
+import com.mongodb.client.model.changestream.FullDocument;
+
+/**
+ * Options applicable to MongoDB <a href="https://docs.mongodb.com/manual/changeStreams/">Change Streams</a>. Intended
+ * to be used along with {@link org.springframework.data.mongodb.core.messaging.ChangeStreamRequest} in a sync world as
+ * well {@link ReactiveMongoOperations} if you prefer it that way.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+@EqualsAndHashCode
+public class ChangeStreamOptions {
+
+	private @Nullable Object filter;
+	private @Nullable BsonValue resumeToken;
+	private @Nullable FullDocument fullDocumentLookup;
+	private @Nullable Collation collation;
+	private @Nullable Instant resumeTimestamp;
+
+	protected ChangeStreamOptions() {}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 */
+	public Optional<Object> getFilter() {
+		return Optional.ofNullable(filter);
+	}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 */
+	public Optional<BsonValue> getResumeToken() {
+		return Optional.ofNullable(resumeToken);
+	}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 */
+	public Optional<FullDocument> getFullDocumentLookup() {
+		return Optional.ofNullable(fullDocumentLookup);
+	}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 */
+	public Optional<Collation> getCollation() {
+		return Optional.ofNullable(collation);
+	}
+
+	/**
+	 * @return {@link Optional#empty()} if not set.
+	 */
+	public Optional<Instant> getResumeTimestamp() {
+		return Optional.ofNullable(resumeTimestamp);
+	}
+
+	/**
+	 * @return empty {@link ChangeStreamOptions}.
+	 */
+	public static ChangeStreamOptions empty() {
+		return ChangeStreamOptions.builder().build();
+	}
+
+	/**
+	 * Obtain a shiny new {@link ChangeStreamOptionsBuilder} and start defining options in this fancy fluent way. Just
+	 * don't forget to call {@link ChangeStreamOptionsBuilder#build() build()} when your're done.
+	 *
+	 * @return new instance of {@link ChangeStreamOptionsBuilder}.
+	 */
+	public static ChangeStreamOptionsBuilder builder() {
+		return new ChangeStreamOptionsBuilder();
+	}
+
+	/**
+	 * Builder for creating {@link ChangeStreamOptions}.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	public static class ChangeStreamOptionsBuilder {
+
+		private @Nullable Object filter;
+		private @Nullable BsonValue resumeToken;
+		private @Nullable FullDocument fullDocumentLookup;
+		private @Nullable Collation collation;
+		private @Nullable Instant resumeTimestamp;
+
+		private ChangeStreamOptionsBuilder() {}
+
+		/**
+		 * Set the collation to use.
+		 *
+		 * @param collation must not be {@literal null} nor {@literal empty}.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder collation(Collation collation) {
+
+			Assert.notNull(collation, "Collation must not be null nor empty!");
+
+			this.collation = collation;
+			return this;
+		}
+
+		/**
+		 * Set the filter to apply.
+		 * <p/>
+		 * Fields on aggregation expression root level are prefixed to map to fields contained in
+		 * {@link ChangeStreamDocument#getFullDocument() fullDocument}. However {@literal operationType}, {@literal ns},
+		 * {@literal documentKey} and {@literal fullDocument} are reserved words that will be omitted, and therefore taken
+		 * as given, during the mapping procedure. You may want to have a look at the
+		 * <a href="https://docs.mongodb.com/manual/reference/change-events/">structure of Change Events</a>.
+		 * <p/>
+		 * Use {@link org.springframework.data.mongodb.core.aggregation.TypedAggregation} to ensure filter expressions are
+		 * mapped to domain type fields.
+		 *
+		 * @param filter the {@link Aggregation Aggregation pipeline} to apply for filtering events. Must not be
+		 *          {@literal null}.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder filter(Aggregation filter) {
+
+			Assert.notNull(filter, "Filter must not be null!");
+
+			this.filter = filter;
+			return this;
+		}
+
+		/**
+		 * Set the plain filter chain to apply.
+		 *
+		 * @param filter must not be {@literal null} nor contain {@literal null} values.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder filter(Document... filter) {
+
+			Assert.noNullElements(filter, "Filter must not contain null values");
+
+			this.filter = Arrays.asList(filter);
+			return this;
+		}
+
+		/**
+		 * Set the resume token (typically a {@link org.bson.BsonDocument} containing a {@link org.bson.BsonBinary binary
+		 * token}) after which to start with listening.
+		 *
+		 * @param resumeToken must not be {@literal null}.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder resumeToken(BsonValue resumeToken) {
+
+			Assert.notNull(resumeToken, "ResumeToken must not be null!");
+
+			this.resumeToken = resumeToken;
+			return this;
+		}
+
+		/**
+		 * Set the {@link FullDocument} lookup to {@link FullDocument#UPDATE_LOOKUP}.
+		 *
+		 * @return this.
+		 * @see #fullDocumentLookup(FullDocument)
+		 */
+		public ChangeStreamOptionsBuilder returnFullDocumentOnUpdate() {
+			return fullDocumentLookup(FullDocument.UPDATE_LOOKUP);
+		}
+
+		/**
+		 * Set the {@link FullDocument} lookup to use.
+		 *
+		 * @param lookup must not be {@literal null}.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder fullDocumentLookup(FullDocument lookup) {
+
+			Assert.notNull(lookup, "Lookup must not be null!");
+
+			this.fullDocumentLookup = lookup;
+			return this;
+		}
+
+		/**
+		 * Set the cluster time to resume from.
+		 *
+		 * @param resumeTimestamp must not be {@literal null}.
+		 * @return this.
+		 */
+		public ChangeStreamOptionsBuilder resumeAt(Instant resumeTimestamp) {
+
+			Assert.notNull(resumeTimestamp, "ResumeTimestamp must not be null!");
+
+			this.resumeTimestamp = resumeTimestamp;
+			return this;
+		}
+
+		/**
+		 * @return the built {@link ChangeStreamOptions}
+		 */
+		public ChangeStreamOptions build() {
+
+			ChangeStreamOptions options = new ChangeStreamOptions();
+
+			options.filter = filter;
+			options.resumeToken = resumeToken;
+			options.fullDocumentLookup = fullDocumentLookup;
+			options.collation = collation;
+			options.resumeTimestamp = resumeTimestamp;
+
+			return options;
+		}
+	}
+}

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

@@ -15,18 +15,27 @@
  */
 package org.springframework.data.mongodb.core;
 
+import lombok.RequiredArgsConstructor;
+
 import java.util.Optional;
 
 import org.springframework.data.mongodb.core.query.Collation;
+import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.data.mongodb.core.validation.Validator;
+import org.springframework.data.util.Optionals;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
+import com.mongodb.client.model.ValidationAction;
+import com.mongodb.client.model.ValidationLevel;
+
 /**
  * Provides a simple wrapper to encapsulate the variety of settings you can use when creating a collection.
  *
  * @author Thomas Risberg
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Andreas Zink
  */
 public class CollectionOptions {
 
@@ -34,6 +43,7 @@ public class CollectionOptions {
 	private @Nullable Long size;
 	private @Nullable Boolean capped;
 	private @Nullable Collation collation;
+	private ValidationOptions validationOptions;
 
 	/**
 	 * Constructs a new <code>CollectionOptions</code> instance.
@@ -46,16 +56,17 @@ public class CollectionOptions {
 	 */
 	@Deprecated
 	public CollectionOptions(@Nullable Long size, @Nullable Long maxDocuments, @Nullable Boolean capped) {
-		this(size, maxDocuments, capped, null);
+		this(size, maxDocuments, capped, null, ValidationOptions.none());
 	}
 
 	private CollectionOptions(@Nullable Long size, @Nullable Long maxDocuments, @Nullable Boolean capped,
-			@Nullable Collation collation) {
+			@Nullable Collation collation, ValidationOptions validationOptions) {
 
 		this.maxDocuments = maxDocuments;
 		this.size = size;
 		this.capped = capped;
 		this.collation = collation;
+		this.validationOptions = validationOptions;
 	}
 
 	/**
@@ -69,7 +80,7 @@ public class CollectionOptions {
 
 		Assert.notNull(collation, "Collation must not be null!");
 
-		return new CollectionOptions(null, null, null, collation);
+		return new CollectionOptions(null, null, null, collation, ValidationOptions.none());
 	}
 
 	/**
@@ -79,7 +90,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public static CollectionOptions empty() {
-		return new CollectionOptions(null, null, null, null);
+		return new CollectionOptions(null, null, null, null, ValidationOptions.none());
 	}
 
 	/**
@@ -90,7 +101,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions capped() {
-		return new CollectionOptions(size, maxDocuments, true, collation);
+		return new CollectionOptions(size, maxDocuments, true, collation, validationOptions);
 	}
 
 	/**
@@ -101,7 +112,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions maxDocuments(long maxDocuments) {
-		return new CollectionOptions(size, maxDocuments, capped, collation);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
 	}
 
 	/**
@@ -112,7 +123,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions size(long size) {
-		return new CollectionOptions(size, maxDocuments, capped, collation);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
 	}
 
 	/**
@@ -123,7 +134,127 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions collation(@Nullable Collation collation) {
-		return new CollectionOptions(size, maxDocuments, capped, collation);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationOptions} set to given
+	 * {@link MongoJsonSchema}.
+	 *
+	 * @param schema can be {@literal null}.
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions schema(@Nullable MongoJsonSchema schema) {
+		return validator(Validator.schema(schema));
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationOptions} set to given
+	 * {@link Validator}.
+	 *
+	 * @param validator can be {@literal null}.
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions validator(@Nullable Validator validator) {
+		return validation(validationOptions.validator(validator));
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationLevel} set to
+	 * {@link ValidationLevel#OFF}.
+	 *
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions disableValidation() {
+		return schemaValidationLevel(ValidationLevel.OFF);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationLevel} set to
+	 * {@link ValidationLevel#STRICT}.
+	 *
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions strictValidation() {
+		return schemaValidationLevel(ValidationLevel.STRICT);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationLevel} set to
+	 * {@link ValidationLevel#MODERATE}.
+	 *
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions moderateValidation() {
+		return schemaValidationLevel(ValidationLevel.MODERATE);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationAction} set to
+	 * {@link ValidationAction#WARN}.
+	 *
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions warnOnValidationError() {
+		return schemaValidationAction(ValidationAction.WARN);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationAction} set to
+	 * {@link ValidationAction#ERROR}.
+	 *
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions failOnValidationError() {
+		return schemaValidationAction(ValidationAction.ERROR);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationLevel} set given
+	 * {@link ValidationLevel}.
+	 *
+	 * @param validationLevel must not be {@literal null}.
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions schemaValidationLevel(ValidationLevel validationLevel) {
+
+		Assert.notNull(validationLevel, "ValidationLevel must not be null!");
+		return validation(validationOptions.validationLevel(validationLevel));
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with already given settings and {@code validationAction} set given
+	 * {@link ValidationAction}.
+	 *
+	 * @param validationAction must not be {@literal null}.
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions schemaValidationAction(ValidationAction validationAction) {
+
+		Assert.notNull(validationAction, "ValidationAction must not be null!");
+		return validation(validationOptions.validationAction(validationAction));
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with the given {@link ValidationOptions}.
+	 *
+	 * @param validationOptions must not be {@literal null}. Use {@link ValidationOptions#none()} to remove validation.
+	 * @return new {@link CollectionOptions}.
+	 * @since 2.1
+	 */
+	public CollectionOptions validation(ValidationOptions validationOptions) {
+
+		Assert.notNull(validationOptions, "ValidationOptions must not be null!");
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
 	}
 
 	/**
@@ -163,4 +294,104 @@ public class CollectionOptions {
 	public Optional<Collation> getCollation() {
 		return Optional.ofNullable(collation);
 	}
+
+	/**
+	 * Get the {@link MongoJsonSchema} for the collection.
+	 *
+	 * @return {@link Optional#empty()} if not set.
+	 * @since 2.1
+	 */
+	public Optional<ValidationOptions> getValidationOptions() {
+		return validationOptions.isEmpty() ? Optional.empty() : Optional.of(validationOptions);
+	}
+
+	/**
+	 * Encapsulation of ValidationOptions options.
+	 *
+	 * @author Christoph Strobl
+	 * @author Andreas Zink
+	 * @since 2.1
+	 */
+	@RequiredArgsConstructor
+	public static class ValidationOptions {
+
+		private static final ValidationOptions NONE = new ValidationOptions(null, null, null);
+
+		private final @Nullable Validator validator;
+		private final @Nullable ValidationLevel validationLevel;
+		private final @Nullable ValidationAction validationAction;
+
+		/**
+		 * Create an empty {@link ValidationOptions}.
+		 *
+		 * @return never {@literal null}.
+		 */
+		public static ValidationOptions none() {
+			return NONE;
+		}
+
+		/**
+		 * Define the {@link Validator} to be used for document validation.
+		 *
+		 * @param validator can be {@literal null}.
+		 * @return new instance of {@link ValidationOptions}.
+		 */
+		public ValidationOptions validator(@Nullable Validator validator) {
+			return new ValidationOptions(validator, validationLevel, validationAction);
+		}
+
+		/**
+		 * Define the validation level to apply.
+		 *
+		 * @param validationLevel can be {@literal null}.
+		 * @return new instance of {@link ValidationOptions}.
+		 */
+		public ValidationOptions validationLevel(ValidationLevel validationLevel) {
+			return new ValidationOptions(validator, validationLevel, validationAction);
+		}
+
+		/**
+		 * Define the validation action to take.
+		 *
+		 * @param validationAction can be {@literal null}.
+		 * @return new instance of {@link ValidationOptions}.
+		 */
+		public ValidationOptions validationAction(ValidationAction validationAction) {
+			return new ValidationOptions(validator, validationLevel, validationAction);
+		}
+
+		/**
+		 * Get the {@link Validator} to use.
+		 *
+		 * @return never {@literal null}.
+		 */
+		public Optional<Validator> getValidator() {
+			return Optional.ofNullable(validator);
+		}
+
+		/**
+		 * Get the {@code validationLevel} to apply.
+		 *
+		 * @return {@link Optional#empty()} if not set.
+		 */
+		public Optional<ValidationLevel> getValidationLevel() {
+			return Optional.ofNullable(validationLevel);
+		}
+
+		/**
+		 * Get the {@code validationAction} to perform.
+		 *
+		 * @return @return {@link Optional#empty()} if not set.
+		 */
+		public Optional<ValidationAction> getValidationAction() {
+			return Optional.ofNullable(validationAction);
+		}
+
+		/**
+		 * @return {@literal true} if no arguments set.
+		 */
+		boolean isEmpty() {
+			return !Optionals.isAnyPresent(getValidator(), getValidationAction(), getValidationLevel());
+		}
+	}
 }

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

@@ -21,7 +21,7 @@ import com.mongodb.client.FindIterable;
 
 /**
  * Simple callback interface to allow customization of a {@link FindIterable}.
- * 
+ *
  * @author Oliver Gierke
  * @author Christoph Strobl
  */
@@ -29,7 +29,7 @@ interface CursorPreparer {
 
 	/**
 	 * Prepare the given cursor (apply limits, skips and so on). Returns the prepared cursor.
-	 * 
+	 *
 	 * @param cursor
 	 */
 	FindIterable<Document> prepare(FindIterable<Document> cursor);

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

@@ -58,6 +58,7 @@ import com.mongodb.client.model.WriteModel;
  * @author Oliver Gierke
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Michail Nikolaev
  * @since 1.9
  */
 class DefaultBulkOperations implements BulkOperations {
@@ -275,18 +276,13 @@ class DefaultBulkOperations implements BulkOperations {
 
 		try {
 
-			MongoCollection<Document> collection = mongoOperations.getCollection(collectionName);
-			if (defaultWriteConcern != null) {
-				collection = collection.withWriteConcern(defaultWriteConcern);
-			}
-
-			return collection.bulkWrite(models.stream().map(this::mapWriteModel).collect(Collectors.toList()), bulkOptions);
-
-		} catch (BulkWriteException o_O) {
-
-			DataAccessException toThrow = exceptionTranslator.translateExceptionIfPossible(o_O);
-			throw toThrow == null ? o_O : toThrow;
+			return mongoOperations.execute(collectionName, collection -> {
 
+				if (defaultWriteConcern != null) {
+					collection = collection.withWriteConcern(defaultWriteConcern);
+				}
+				return collection.bulkWrite(models.stream().map(this::mapWriteModel).collect(Collectors.toList()), bulkOptions);
+			});
 		} finally {
 			this.bulkOptions = getBulkWriteOptions(bulkOperationContext.getBulkMode());
 		}

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

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.mongodb.core;
 
-import static org.springframework.data.mongodb.core.MongoTemplate.*;
-
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -50,18 +48,22 @@ public class DefaultIndexOperations implements IndexOperations {
 
 	private static final String PARTIAL_FILTER_EXPRESSION_KEY = "partialFilterExpression";
 
-	private final MongoDbFactory mongoDbFactory;
 	private final String collectionName;
 	private final QueryMapper mapper;
 	private final @Nullable Class<?> type;
 
+	private MongoOperations mongoOperations;
+
 	/**
 	 * Creates a new {@link DefaultIndexOperations}.
 	 *
 	 * @param mongoDbFactory must not be {@literal null}.
 	 * @param collectionName must not be {@literal null}.
 	 * @param queryMapper must not be {@literal null}.
+	 * @deprecated since 2.1. Please use
+	 *             {@link DefaultIndexOperations#DefaultIndexOperations(MongoOperations, String, Class)}.
 	 */
+	@Deprecated
 	public DefaultIndexOperations(MongoDbFactory mongoDbFactory, String collectionName, QueryMapper queryMapper) {
 		this(mongoDbFactory, collectionName, queryMapper, null);
 	}
@@ -74,7 +76,10 @@ public class DefaultIndexOperations implements IndexOperations {
 	 * @param queryMapper must not be {@literal null}.
 	 * @param type Type used for mapping potential partial index filter expression. Can be {@literal null}.
 	 * @since 1.10
+	 * @deprecated since 2.1. Please use
+	 *             {@link DefaultIndexOperations#DefaultIndexOperations(MongoOperations, String, Class)}.
 	 */
+	@Deprecated
 	public DefaultIndexOperations(MongoDbFactory mongoDbFactory, String collectionName, QueryMapper queryMapper,
 			@Nullable Class<?> type) {
 
@@ -82,10 +87,29 @@ public class DefaultIndexOperations implements IndexOperations {
 		Assert.notNull(collectionName, "Collection name can not be null!");
 		Assert.notNull(queryMapper, "QueryMapper must not be null!");
 
-		this.mongoDbFactory = mongoDbFactory;
 		this.collectionName = collectionName;
 		this.mapper = queryMapper;
 		this.type = type;
+		this.mongoOperations = new MongoTemplate(mongoDbFactory);
+	}
+
+	/**
+	 * Creates a new {@link DefaultIndexOperations}.
+	 *
+	 * @param mongoOperations must not be {@literal null}.
+	 * @param collectionName must not be {@literal null} or empty.
+	 * @param type can be {@literal null}.
+	 * @since 2.1
+	 */
+	public DefaultIndexOperations(MongoOperations mongoOperations, String collectionName, @Nullable Class<?> type) {
+
+		Assert.notNull(mongoOperations, "MongoOperations must not be null!");
+		Assert.hasText(collectionName, "Collection name must not be null or empty!");
+
+		this.mongoOperations = mongoOperations;
+		this.mapper = new QueryMapper(mongoOperations.getConverter());
+		this.collectionName = collectionName;
+		this.type = type;
 	}
 
 	/*
@@ -187,11 +211,10 @@ public class DefaultIndexOperations implements IndexOperations {
 
 		Assert.notNull(callback, "CollectionCallback must not be null!");
 
-		try {
-			MongoCollection<Document> collection = mongoDbFactory.getDb().getCollection(collectionName);
-			return callback.doInCollection(collection);
-		} catch (RuntimeException e) {
-			throw potentiallyConvertRuntimeException(e, mongoDbFactory.getExceptionTranslator());
+		if (type != null) {
+			return mongoOperations.execute(type, callback);
 		}
+
+		return mongoOperations.execute(collectionName, callback);
 	}
 }

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

@@ -26,7 +26,7 @@ import com.mongodb.MongoException;
  * about exception handling. {@MongoException}s will be caught and translated by the calling MongoTemplate An
  * DocumentCallbackHandler is typically stateful: It keeps the result state within the object, to be available later for
  * later inspection.
- * 
+ *
  * @author Mark Pollack
  * @author Grame Rocher
  * @author Oliver Gierke

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

@@ -0,0 +1,670 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.AccessLevel;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Collection;
+import java.util.Map;
+
+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.PersistentPropertyAccessor;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
+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.Criteria;
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+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.
+ *
+ * @author Oliver Gierke
+ * @author Mark Paluch
+ * @author Christoph Strobl
+ * @since 2.1
+ * @see MongoTemplate
+ * @see ReactiveMongoTemplate
+ */
+@RequiredArgsConstructor
+class EntityOperations {
+
+	private static final String ID_FIELD = "_id";
+
+	private final @NonNull MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context;
+
+	/**
+	 * Creates a new {@link Entity} for the given bean.
+	 *
+	 * @param entity must not be {@literal null}.
+	 * @return
+	 */
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	public <T> Entity<T> forEntity(T entity) {
+
+		Assert.notNull(entity, "Bean must not be null!");
+
+		if (entity instanceof String) {
+			return new UnmappedEntity(parse(entity.toString()));
+		}
+
+		if (entity instanceof Map) {
+			return new SimpleMappedEntity((Map<String, Object>) entity);
+		}
+
+		return MappedEntity.of(entity, context);
+	}
+
+	/**
+	 * Creates a new {@link AdaptibleEntity} for the given bean and {@link ConversionService}.
+	 *
+	 * @param entity must not be {@literal null}.
+	 * @param conversionService must not be {@literal null}.
+	 * @return
+	 */
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	public <T> AdaptibleEntity<T> forEntity(T entity, ConversionService conversionService) {
+
+		Assert.notNull(entity, "Bean must not be null!");
+		Assert.notNull(conversionService, "ConversionService must not be null!");
+
+		if (entity instanceof String) {
+			return new UnmappedEntity(parse(entity.toString()));
+		}
+
+		if (entity instanceof Map) {
+			return new SimpleMappedEntity((Map<String, Object>) entity);
+		}
+
+		return AdaptibleMappedEntity.of(entity, context, conversionService);
+	}
+
+	public String determineCollectionName(@Nullable Class<?> entityClass) {
+
+		if (entityClass == null) {
+			throw new InvalidDataAccessApiUsageException(
+					"No class parameter provided, entity collection can't be determined!");
+		}
+
+		return context.getRequiredPersistentEntity(entityClass).getCollection();
+	}
+
+	public Query getByIdInQuery(Collection<?> entities) {
+
+		MultiValueMap<String, Object> byIds = new LinkedMultiValueMap<>();
+
+		entities.stream() //
+				.map(this::forEntity) //
+				.forEach(it -> byIds.add(it.getIdFieldName(), it.getId()));
+
+		Criteria[] criterias = byIds.entrySet().stream() //
+				.map(it -> Criteria.where(it.getKey()).in(it.getValue())) //
+				.toArray(Criteria[]::new);
+
+		return new Query(criterias.length == 1 ? criterias[0] : new Criteria().orOperator(criterias));
+	}
+
+	/**
+	 * Returns the name of the identifier property. Considers mapping information but falls back to the MongoDB default of
+	 * {@code _id} if no identifier property can be found.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return
+	 */
+	public String getIdPropertyName(Class<?> type) {
+
+		Assert.notNull(type, "Type must not be null!");
+
+		MongoPersistentEntity<?> persistentEntity = context.getPersistentEntity(type);
+
+		if (persistentEntity != null && persistentEntity.getIdProperty() != null) {
+			return persistentEntity.getRequiredIdProperty().getName();
+		}
+
+		return ID_FIELD;
+	}
+
+	private static Document parse(String source) {
+
+		try {
+			return Document.parse(source);
+		} catch (JSONParseException | org.bson.json.JsonParseException o_O) {
+			throw new MappingException("Could not parse given String to save into a JSON document!", o_O);
+		}
+	}
+
+	/**
+	 * A representation of information about an entity.
+	 *
+	 * @author Oliver Gierke
+	 * @since 2.1
+	 */
+	interface Entity<T> {
+
+		/**
+		 * Returns the field name of the identifier of the entity.
+		 *
+		 * @return
+		 */
+		String getIdFieldName();
+
+		/**
+		 * Returns the identifier of the entity.
+		 *
+		 * @return
+		 */
+		Object getId();
+
+		/**
+		 * Returns the {@link Query} to find the entity by its identifier.
+		 *
+		 * @return
+		 */
+		Query getByIdQuery();
+
+		/**
+		 * Returns the {@link Query} to find the entity in its current version.
+		 *
+		 * @return
+		 */
+		Query getQueryForVersion();
+
+		/**
+		 * Maps the backing entity into a {@link MappedDocument} using the given {@link MongoWriter}.
+		 *
+		 * @param writer must not be {@literal null}.
+		 * @return
+		 */
+		MappedDocument toMappedDocument(MongoWriter<? super T> writer);
+
+		/**
+		 * Asserts that the identifier type is updatable in case its not already set.
+		 */
+		default void assertUpdateableIdIfNotSet() {}
+
+		/**
+		 * Returns whether the entity is versioned, i.e. if it contains a version property.
+		 *
+		 * @return
+		 */
+		default boolean isVersionedEntity() {
+			return false;
+		}
+
+		/**
+		 * Returns the value of the version if the entity has a version property, {@literal null} otherwise.
+		 *
+		 * @return
+		 */
+		@Nullable
+		Object getVersion();
+
+		/**
+		 * Returns the underlying bean.
+		 *
+		 * @return
+		 */
+		T getBean();
+
+		/**
+		 * Returns whether the entity is considered to be new.
+		 * 
+		 * @return
+		 * @since 2.1.2
+		 */
+		boolean isNew();
+	}
+
+	/**
+	 * Information and commands on an entity.
+	 *
+	 * @author Oliver Gierke
+	 * @since 2.1
+	 */
+	interface AdaptibleEntity<T> extends Entity<T> {
+
+		/**
+		 * Populates the identifier of the backing entity if it has an identifier property and there's no identifier
+		 * currently present.
+		 *
+		 * @param id must not be {@literal null}.
+		 * @return
+		 */
+		@Nullable
+		T populateIdIfNecessary(@Nullable Object id);
+
+		/**
+		 * Initializes the version property of the of the current entity if available.
+		 *
+		 * @return the entity with the version property updated if available.
+		 */
+		T initializeVersionProperty();
+
+		/**
+		 * Increments the value of the version property if available.
+		 *
+		 * @return the entity with the version property incremented if available.
+		 */
+		T incrementVersion();
+
+		/**
+		 * 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.
+		 */
+		@Nullable
+		Number getVersion();
+	}
+
+	@RequiredArgsConstructor
+	private static class UnmappedEntity<T extends Map<String, Object>> implements AdaptibleEntity<T> {
+
+		private final T map;
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getIdPropertyName()
+		 */
+		@Override
+		public String getIdFieldName() {
+			return ID_FIELD;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getId()
+		 */
+		@Override
+		public Object getId() {
+			return map.get(ID_FIELD);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getByIdQuery()
+		 */
+		@Override
+		public Query getByIdQuery() {
+			return Query.query(Criteria.where(ID_FIELD).is(map.get(ID_FIELD)));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.MutablePersistableSource#populateIdIfNecessary(java.lang.Object)
+		 */
+		@Nullable
+		@Override
+		public T populateIdIfNecessary(@Nullable Object id) {
+
+			map.put(ID_FIELD, id);
+
+			return map;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getQueryForVersion()
+		 */
+		@Override
+		public Query getQueryForVersion() {
+			throw new MappingException("Cannot query for version on plain Documents!");
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#toMappedDocument(org.springframework.data.mongodb.core.convert.MongoWriter)
+		 */
+		@Override
+		public MappedDocument toMappedDocument(MongoWriter<? super T> writer) {
+			return MappedDocument.of(map instanceof Document //
+					? (Document) map //
+					: new Document(map));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.MutablePersistableSource#initializeVersionProperty()
+		 */
+		@Override
+		public T initializeVersionProperty() {
+			return map;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.MutablePersistableSource#getVersion()
+		 */
+		@Override
+		@Nullable
+		public Number getVersion() {
+			return null;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.MutablePersistableSource#incrementVersion()
+		 */
+		@Override
+		public T incrementVersion() {
+			return map;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getBean()
+		 */
+		@Override
+		public T getBean() {
+			return map;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#isNew()
+		 */
+		@Override
+		public boolean isNew() {
+			return map.get(ID_FIELD) != null;
+		}
+	}
+
+	private static class SimpleMappedEntity<T extends Map<String, Object>> extends UnmappedEntity<T> {
+
+		SimpleMappedEntity(T map) {
+			super(map);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#toMappedDocument(org.springframework.data.mongodb.core.convert.MongoWriter)
+		 */
+		@Override
+		@SuppressWarnings("unchecked")
+		public MappedDocument toMappedDocument(MongoWriter<? super T> writer) {
+
+			T bean = getBean();
+			bean = (T) (bean instanceof Document //
+					? (Document) bean //
+					: new Document(bean));
+			Document document = new Document();
+			writer.write(bean, document);
+
+			return MappedDocument.of(document);
+		}
+	}
+
+	@RequiredArgsConstructor(access = AccessLevel.PROTECTED)
+	private static class MappedEntity<T> implements Entity<T> {
+
+		private final @NonNull MongoPersistentEntity<?> entity;
+		private final @NonNull IdentifierAccessor idAccessor;
+		private final @NonNull PersistentPropertyAccessor<T> propertyAccessor;
+
+		private static <T> MappedEntity<T> of(T bean,
+				MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context) {
+
+			MongoPersistentEntity<?> entity = context.getRequiredPersistentEntity(bean.getClass());
+			IdentifierAccessor identifierAccessor = entity.getIdentifierAccessor(bean);
+			PersistentPropertyAccessor<T> propertyAccessor = entity.getPropertyAccessor(bean);
+
+			return new MappedEntity<>(entity, identifierAccessor, propertyAccessor);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getIdPropertyName()
+		 */
+		@Override
+		public String getIdFieldName() {
+			return entity.getRequiredIdProperty().getFieldName();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getId()
+		 */
+		@Override
+		public Object getId() {
+			return idAccessor.getRequiredIdentifier();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getByIdQuery()
+		 */
+		@Override
+		public Query getByIdQuery() {
+
+			if (!entity.hasIdProperty()) {
+				throw new MappingException("No id property found for object of type " + entity.getType() + "!");
+			}
+
+			MongoPersistentProperty idProperty = entity.getRequiredIdProperty();
+
+			return Query.query(Criteria.where(idProperty.getName()).is(getId()));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getQueryForVersion(java.lang.Object)
+		 */
+		@Override
+		public Query getQueryForVersion() {
+
+			MongoPersistentProperty idProperty = entity.getRequiredIdProperty();
+			MongoPersistentProperty property = entity.getRequiredVersionProperty();
+
+			return new Query(Criteria.where(idProperty.getName()).is(getId())//
+					.and(property.getName()).is(getVersion()));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#toMappedDocument(org.springframework.data.mongodb.core.convert.MongoWriter)
+		 */
+		@Override
+		public MappedDocument toMappedDocument(MongoWriter<? super T> writer) {
+
+			T bean = propertyAccessor.getBean();
+
+			Document document = new Document();
+			writer.write(bean, document);
+
+			if (document.containsKey(ID_FIELD) && document.get(ID_FIELD) == null) {
+				document.remove(ID_FIELD);
+			}
+
+			return MappedDocument.of(document);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#assertUpdateableIdIfNotSet()
+		 */
+		public void assertUpdateableIdIfNotSet() {
+
+			if (!entity.hasIdProperty()) {
+				return;
+			}
+
+			MongoPersistentProperty property = entity.getRequiredIdProperty();
+			Object propertyValue = idAccessor.getIdentifier();
+
+			if (propertyValue != null) {
+				return;
+			}
+
+			if (!MongoSimpleTypes.AUTOGENERATED_ID_TYPES.contains(property.getType())) {
+				throw new InvalidDataAccessApiUsageException(
+						String.format("Cannot autogenerate id of type %s for entity of type %s!", property.getType().getName(),
+								entity.getType().getName()));
+			}
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#isVersionedEntity()
+		 */
+		@Override
+		public boolean isVersionedEntity() {
+			return entity.hasVersionProperty();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getVersion()
+		 */
+		@Override
+		@Nullable
+		public Object getVersion() {
+			return propertyAccessor.getProperty(entity.getRequiredVersionProperty());
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.PersistableSource#getBean()
+		 */
+		@Override
+		public T getBean() {
+			return propertyAccessor.getBean();
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#isNew()
+		 */
+		@Override
+		public boolean isNew() {
+			return entity.isNew(propertyAccessor.getBean());
+		}
+	}
+
+	private static class AdaptibleMappedEntity<T> extends MappedEntity<T> implements AdaptibleEntity<T> {
+
+		private final MongoPersistentEntity<?> entity;
+		private final ConvertingPropertyAccessor<T> propertyAccessor;
+		private final IdentifierAccessor identifierAccessor;
+
+		private AdaptibleMappedEntity(MongoPersistentEntity<?> entity, IdentifierAccessor identifierAccessor,
+				ConvertingPropertyAccessor<T> propertyAccessor) {
+
+			super(entity, identifierAccessor, propertyAccessor);
+
+			this.entity = entity;
+			this.propertyAccessor = propertyAccessor;
+			this.identifierAccessor = identifierAccessor;
+		}
+
+		private static <T> AdaptibleEntity<T> of(T bean,
+				MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context,
+				ConversionService conversionService) {
+
+			MongoPersistentEntity<?> entity = context.getRequiredPersistentEntity(bean.getClass());
+			IdentifierAccessor identifierAccessor = entity.getIdentifierAccessor(bean);
+			PersistentPropertyAccessor<T> propertyAccessor = entity.getPropertyAccessor(bean);
+
+			return new AdaptibleMappedEntity<>(entity, identifierAccessor,
+					new ConvertingPropertyAccessor<>(propertyAccessor, conversionService));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity#populateIdIfNecessary(java.lang.Object)
+		 */
+		@Nullable
+		@Override
+		public T populateIdIfNecessary(@Nullable Object id) {
+
+			if (id == null) {
+				return propertyAccessor.getBean();
+			}
+
+			MongoPersistentProperty idProperty = entity.getIdProperty();
+			if (idProperty == null) {
+				return propertyAccessor.getBean();
+			}
+
+			if (identifierAccessor.getIdentifier() != null) {
+				return propertyAccessor.getBean();
+			}
+
+			propertyAccessor.setProperty(idProperty, id);
+			return propertyAccessor.getBean();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.MappedEntity#getVersion()
+		 */
+		@Override
+		@Nullable
+		public Number getVersion() {
+
+			MongoPersistentProperty versionProperty = entity.getRequiredVersionProperty();
+
+			return propertyAccessor.getProperty(versionProperty, Number.class);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity#initializeVersionProperty()
+		 */
+		@Override
+		public T initializeVersionProperty() {
+
+			if (!entity.hasVersionProperty()) {
+				return propertyAccessor.getBean();
+			}
+
+			MongoPersistentProperty versionProperty = entity.getRequiredVersionProperty();
+
+			propertyAccessor.setProperty(versionProperty, versionProperty.getType().isPrimitive() ? 1 : 0);
+
+			return propertyAccessor.getBean();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity#incrementVersion()
+		 */
+		@Override
+		public T incrementVersion() {
+
+			MongoPersistentProperty versionProperty = entity.getRequiredVersionProperty();
+			Number version = getVersion();
+			Number nextVersion = version == null ? 0 : version.longValue() + 1;
+
+			propertyAccessor.setProperty(versionProperty, nextVersion);
+
+			return propertyAccessor.getBean();
+		}
+	}
+}

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

@@ -35,22 +35,10 @@ import org.springframework.util.StringUtils;
  * @author Mark Paluch
  * @since 2.0
  */
+@RequiredArgsConstructor
 class ExecutableAggregationOperationSupport implements ExecutableAggregationOperation {
 
-	private final MongoTemplate template;
-
-	/**
-	 * Create new instance of {@link ExecutableAggregationOperationSupport}.
-	 *
-	 * @param template must not be {@literal null}.
-	 * @throws IllegalArgumentException if template is {@literal null}.
-	 */
-	ExecutableAggregationOperationSupport(MongoTemplate template) {
-
-		Assert.notNull(template, "Template must not be null!");
-
-		this.template = template;
-	}
+	private final @NonNull MongoTemplate template;
 
 	/*
 	 * (non-Javadoc)
@@ -131,11 +119,11 @@ class ExecutableAggregationOperationSupport implements ExecutableAggregationOper
 				TypedAggregation<?> typedAggregation = (TypedAggregation<?>) aggregation;
 
 				if (typedAggregation.getInputType() != null) {
-					return template.determineCollectionName(typedAggregation.getInputType());
+					return template.getCollectionName(typedAggregation.getInputType());
 				}
 			}
 
-			return template.determineCollectionName(domainType);
+			return template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -19,11 +19,14 @@ import java.util.List;
 import java.util.Optional;
 import java.util.stream.Stream;
 
+import org.springframework.dao.DataAccessException;
 import org.springframework.data.geo.GeoResults;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.lang.Nullable;
 
+import com.mongodb.client.MongoCollection;
+
 /**
  * {@link ExecutableFindOperation} allows creation and execution of MongoDB find operations in a fluent API style.
  * <br />
@@ -202,7 +205,7 @@ public interface ExecutableFindOperation {
 	 * @author Christoph Strobl
 	 * @since 2.0
 	 */
-	interface FindWithProjection<T> extends FindWithQuery<T> {
+	interface FindWithProjection<T> extends FindWithQuery<T>, FindDistinct {
 
 		/**
 		 * Define the target type fields should be mapped to. <br />
@@ -214,6 +217,101 @@ public interface ExecutableFindOperation {
 		 * @throws IllegalArgumentException if resultType is {@literal null}.
 		 */
 		<R> FindWithQuery<R> as(Class<R> resultType);
+
+	}
+
+	/**
+	 * Distinct Find support.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface FindDistinct {
+
+		/**
+		 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view.
+		 *
+		 * @param field name of the field. Must not be {@literal null}.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if field is {@literal null}.
+		 */
+		TerminatingDistinct<Object> distinct(String field);
+	}
+
+	/**
+	 * Result type override. Optional.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface DistinctWithProjection {
+
+		/**
+		 * Define the target type the result should be mapped to. <br />
+		 * Skip this step if you are anyway fine with the default conversion.
+		 * <dl>
+		 * <dt>{@link Object} (the default)</dt>
+		 * <dd>Result is mapped according to the {@link org.bson.BsonType} converting eg. {@link org.bson.BsonString} into
+		 * plain {@link String}, {@link org.bson.BsonInt64} to {@link Long}, etc. always picking the most concrete type with
+		 * respect to the domain types property.<br />
+		 * Any {@link org.bson.BsonType#DOCUMENT} is run through the {@link org.springframework.data.convert.EntityReader}
+		 * to obtain the domain type. <br />
+		 * Using {@link Object} also works for non strictly typed fields. Eg. a mixture different types like fields using
+		 * {@link String} in one {@link org.bson.Document} while {@link Long} in another.</dd>
+		 * <dt>Any Simple type like {@link String} or {@link Long}.</dt>
+		 * <dd>The result is mapped directly by the MongoDB Java driver and the {@link org.bson.codecs.CodeCodec Codecs} in
+		 * place. This works only for results where all documents considered for the operation use the very same type for
+		 * the field.</dd>
+		 * <dt>Any Domain type</dt>
+		 * <dd>Domain types can only be mapped if the if the result of the actual {@code distinct()} operation returns
+		 * {@link org.bson.BsonType#DOCUMENT}.</dd>
+		 * <dt>{@link org.bson.BsonValue}</dt>
+		 * <dd>Using {@link org.bson.BsonValue} allows retrieval of the raw driver specific format, which returns eg.
+		 * {@link org.bson.BsonString}.</dd>
+		 * </dl>
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> TerminatingDistinct<R> as(Class<R> resultType);
+	}
+
+	/**
+	 * Result restrictions. Optional.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface DistinctWithQuery<T> extends DistinctWithProjection {
+
+		/**
+		 * Set the filter query to be used.
+		 *
+		 * @param query must not be {@literal null}.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		TerminatingDistinct<T> matching(Query query);
+	}
+
+	/**
+	 * Terminating distinct find operations.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface TerminatingDistinct<T> extends DistinctWithQuery<T> {
+
+		/**
+		 * Get all matching distinct field values.
+		 *
+		 * @return empty {@link List} if not match found. Never {@literal null}.
+		 * @throws DataAccessException if eg. result cannot be converted correctly which may happen if the document contains
+		 *           {@link String} whereas the result type is specified as {@link Long}.
+		 */
+		List<T> all();
 	}
 
 	/**
@@ -222,5 +320,5 @@ public interface ExecutableFindOperation {
 	 * @author Christoph Strobl
 	 * @since 2.0
 	 */
-	interface ExecutableFind<T> extends FindWithCollection<T>, FindWithProjection<T> {}
+	interface ExecutableFind<T> extends FindWithCollection<T>, FindWithProjection<T>, FindDistinct {}
 }

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

@@ -45,24 +45,12 @@ import com.mongodb.client.FindIterable;
  * @author Mark Paluch
  * @since 2.0
  */
+@RequiredArgsConstructor
 class ExecutableFindOperationSupport implements ExecutableFindOperation {
 
 	private static final Query ALL_QUERY = new Query();
 
-	private final MongoTemplate template;
-
-	/**
-	 * Create new {@link ExecutableFindOperationSupport}.
-	 *
-	 * @param template must not be {@literal null}.
-	 * @throws IllegalArgumentException if template is {@literal null}.
-	 */
-	ExecutableFindOperationSupport(MongoTemplate template) {
-
-		Assert.notNull(template, "Template must not be null!");
-
-		this.template = template;
-	}
+	private final @NonNull MongoTemplate template;
 
 	/*
 	 * (non-Javadoc)
@@ -205,6 +193,19 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return template.exists(query, domainType, getCollectionName());
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.FindDistinct#distinct(java.lang.String)
+		 */
+		@SuppressWarnings("unchecked")
+		@Override
+		public TerminatingDistinct<Object> distinct(String field) {
+
+			Assert.notNull(field, "Field must not be null!");
+
+			return new DistinctOperationSupport(this, field);
+		}
+
 		private List<T> doFind(@Nullable CursorPreparer preparer) {
 
 			Document queryObject = query.getQueryObject();
@@ -214,6 +215,12 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 					getCursorPreparer(query, preparer));
 		}
 
+		private List<T> doFindDistinct(String field) {
+
+			return template.findDistinct(query, field, getCollectionName(), domainType,
+					returnType == domainType ? (Class<T>) Object.class : returnType);
+		}
+
 		private CloseableIterator<T> doStream() {
 			return template.doStream(query, domainType, getCollectionName(), returnType);
 		}
@@ -223,7 +230,7 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 
 		private String asString() {
@@ -261,4 +268,54 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return this;
 		}
 	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	static class DistinctOperationSupport<T> implements TerminatingDistinct<T> {
+
+		private final String field;
+		private final ExecutableFindSupport<T> delegate;
+
+		public DistinctOperationSupport(ExecutableFindSupport<T> delegate, String field) {
+
+			this.delegate = delegate;
+			this.field = field;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.DistinctWithProjection#as(java.lang.Class)
+		 */
+		@Override
+		@SuppressWarnings("unchecked")
+		public <R> TerminatingDistinct<R> as(Class<R> resultType) {
+
+			Assert.notNull(resultType, "ResultType must not be null!");
+
+			return new DistinctOperationSupport<>((ExecutableFindSupport) delegate.as(resultType), field);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.DistinctWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
+		 */
+		@Override
+		public TerminatingDistinct<T> matching(Query query) {
+
+			Assert.notNull(query, "Query must not be null!");
+
+			return new DistinctOperationSupport<>((ExecutableFindSupport<T>) delegate.matching(query), field);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingDistinct#all()
+		 */
+		@Override
+		public List<T> all() {
+			return delegate.doFindDistinct(field);
+		}
+	}
 }

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

@@ -63,17 +63,19 @@ public interface ExecutableInsertOperation {
 		 * Insert exactly one object.
 		 *
 		 * @param object must not be {@literal null}.
+		 * @return the inserted object.
 		 * @throws IllegalArgumentException if object is {@literal null}.
 		 */
-		void one(T object);
+		T one(T object);
 
 		/**
 		 * Insert a collection of objects.
 		 *
 		 * @param objects must not be {@literal null}.
+		 * @return the inserted objects.
 		 * @throws IllegalArgumentException if objects is {@literal null}.
 		 */
-		void all(Collection<? extends T> objects);
+		Collection<? extends T> all(Collection<? extends T> objects);
 	}
 
 	/**

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

@@ -37,22 +37,10 @@ import com.mongodb.bulk.BulkWriteResult;
  * @author Mark Paluch
  * @since 2.0
  */
+@RequiredArgsConstructor
 class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 
-	private final MongoTemplate template;
-
-	/**
-	 * Create new {@link ExecutableInsertOperationSupport}.
-	 *
-	 * @param template must not be {@literal null}.
-	 * @throws IllegalArgumentException if template is {@literal null}.
-	 */
-	ExecutableInsertOperationSupport(MongoTemplate template) {
-
-		Assert.notNull(template, "Template must not be null!");
-
-		this.template = template;
-	}
+	private final @NonNull MongoTemplate template;
 
 	/*
 	 * (non-Javadoc)
@@ -84,11 +72,11 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.TerminatingInsert#insert(java.lang.Class)
 		 */
 		@Override
-		public void one(T object) {
+		public T one(T object) {
 
 			Assert.notNull(object, "Object must not be null!");
 
-			template.insert(object, getCollectionName());
+			return template.insert(object, getCollectionName());
 		}
 
 		/*
@@ -96,11 +84,11 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.TerminatingInsert#all(java.util.Collection)
 		 */
 		@Override
-		public void all(Collection<? extends T> objects) {
+		public Collection<T> all(Collection<? extends T> objects) {
 
 			Assert.notNull(objects, "Objects must not be null!");
 
-			template.insert(objects, getCollectionName());
+			return template.insert(objects, getCollectionName());
 		}
 
 		/*
@@ -141,7 +129,7 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -0,0 +1,199 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import java.util.List;
+
+import org.springframework.data.mongodb.core.ExecutableFindOperation.ExecutableFind;
+import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
+import org.springframework.data.mongodb.core.query.Query;
+
+/**
+ * {@link ExecutableMapReduceOperation} allows creation and execution of MongoDB mapReduce operations in a fluent API
+ * style. The starting {@literal domainType} is used for mapping an optional {@link Query} provided via {@code matching}
+ * into the MongoDB specific representation. By default, the originating {@literal domainType} is also used for mapping
+ * back the results from the {@link org.bson.Document}. However, it is possible to define an different
+ * {@literal returnType} via {@code as} to mapping the result.<br />
+ * The collection to operate on is by default derived from the initial {@literal domainType} and can be defined there
+ * via {@link org.springframework.data.mongodb.core.mapping.Document}. Using {@code inCollection} allows to override the
+ * collection name for the execution.
+ * 
+ * <pre>
+ *     <code>
+ *         mapReduce(Human.class)
+ *             .map("function() { emit(this.id, this.firstname) }")
+ *             .reduce("function(id, name) { return sum(id, name); }")
+ *             .inCollection("star-wars")
+ *             .as(Jedi.class)
+ *             .matching(query(where("lastname").is("skywalker")))
+ *             .all();
+ *     </code>
+ * </pre>
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+public interface ExecutableMapReduceOperation {
+
+	/**
+	 * Start creating a mapReduce operation for the given {@literal domainType}.
+	 *
+	 * @param domainType must not be {@literal null}.
+	 * @return new instance of {@link ExecutableFind}.
+	 * @throws IllegalArgumentException if domainType is {@literal null}.
+	 */
+	<T> MapReduceWithMapFunction<T> mapReduce(Class<T> domainType);
+
+	/**
+	 * Trigger mapReduce execution by calling one of the terminating methods.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface TerminatingMapReduce<T> {
+
+		/**
+		 * Get the mapReduce results.
+		 *
+		 * @return never {@literal null}.
+		 */
+		List<T> all();
+	}
+
+	/**
+	 * Provide the Javascript {@code function()} used to map matching documents.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithMapFunction<T> {
+
+		/**
+		 * Set the Javascript map {@code function()}.
+		 *
+		 * @param mapFunction must not be {@literal null} nor empty.
+		 * @return new instance of {@link MapReduceWithReduceFunction}.
+		 * @throws IllegalArgumentException if {@literal mapFunction} is {@literal null} or empty.
+		 */
+		MapReduceWithReduceFunction<T> map(String mapFunction);
+
+	}
+
+	/**
+	 * Provide the Javascript {@code function()} used to reduce matching documents.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithReduceFunction<T> {
+
+		/**
+		 * Set the Javascript map {@code function()}.
+		 *
+		 * @param reduceFunction must not be {@literal null} nor empty.
+		 * @return new instance of {@link ExecutableMapReduce}.
+		 * @throws IllegalArgumentException if {@literal reduceFunction} is {@literal null} or empty.
+		 */
+		ExecutableMapReduce<T> reduce(String reduceFunction);
+
+	}
+
+	/**
+	 * Collection override (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithCollection<T> extends MapReduceWithQuery<T> {
+
+		/**
+		 * Explicitly set the name of the collection to perform the mapReduce operation on. <br />
+		 * Skip this step to use the default collection derived from the domain type.
+		 *
+		 * @param collection must not be {@literal null} nor {@literal empty}.
+		 * @return new instance of {@link MapReduceWithProjection}.
+		 * @throws IllegalArgumentException if collection is {@literal null}.
+		 */
+		MapReduceWithProjection<T> inCollection(String collection);
+	}
+
+	/**
+	 * Input document filter query (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithQuery<T> extends TerminatingMapReduce<T> {
+
+		/**
+		 * Set the filter query to be used.
+		 *
+		 * @param query must not be {@literal null}.
+		 * @return new instance of {@link TerminatingMapReduce}.
+		 * @throws IllegalArgumentException if query is {@literal null}.
+		 */
+		TerminatingMapReduce<T> matching(Query query);
+	}
+
+	/**
+	 * Result type override (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithProjection<T> extends MapReduceWithQuery<T> {
+
+		/**
+		 * Define the target type fields should be mapped to. <br />
+		 * Skip this step if you are anyway only interested in the original domain type.
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link TerminatingMapReduce}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> MapReduceWithQuery<R> as(Class<R> resultType);
+	}
+
+	/**
+	 * Additional mapReduce options (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithOptions<T> {
+
+		/**
+		 * Set additional options to apply to the mapReduce operation.
+		 *
+		 * @param options must not be {@literal null}.
+		 * @return new instance of {@link ExecutableMapReduce}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
+		 */
+		ExecutableMapReduce<T> with(MapReduceOptions options);
+	}
+
+	/**
+	 * {@link ExecutableMapReduce} provides methods for constructing mapReduce operations in a fluent way.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface ExecutableMapReduce<T> extends MapReduceWithMapFunction<T>, MapReduceWithReduceFunction<T>,
+			MapReduceWithCollection<T>, MapReduceWithProjection<T>, MapReduceWithOptions<T> {
+
+	}
+}

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

@@ -0,0 +1,177 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
+import java.util.List;
+
+import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Implementation of {@link ExecutableMapReduceOperation}.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+@RequiredArgsConstructor
+class ExecutableMapReduceOperationSupport implements ExecutableMapReduceOperation {
+
+	private static final Query ALL_QUERY = new Query();
+
+	private final @NonNull MongoTemplate template;
+
+	/*
+	 * (non-Javascript)
+	 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation#mapReduce(java.lang.Class)
+	 */
+	@Override
+	public <T> ExecutableMapReduceSupport<T> mapReduce(Class<T> domainType) {
+
+		Assert.notNull(domainType, "DomainType must not be null!");
+
+		return new ExecutableMapReduceSupport<>(template, domainType, domainType, null, ALL_QUERY, null, null, null);
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	static class ExecutableMapReduceSupport<T>
+			implements ExecutableMapReduce<T>, MapReduceWithOptions<T>, MapReduceWithCollection<T>,
+			MapReduceWithProjection<T>, MapReduceWithQuery<T>, MapReduceWithReduceFunction<T>, MapReduceWithMapFunction<T> {
+
+		private final MongoTemplate template;
+		private final Class<?> domainType;
+		private final Class<T> returnType;
+		private final @Nullable String collection;
+		private final Query query;
+		private final @Nullable String mapFunction;
+		private final @Nullable String reduceFunction;
+		private final @Nullable MapReduceOptions options;
+
+		ExecutableMapReduceSupport(MongoTemplate template, Class<?> domainType, Class<T> returnType,
+				@Nullable String collection, Query query, @Nullable String mapFunction, @Nullable String reduceFunction,
+				@Nullable MapReduceOptions options) {
+
+			this.template = template;
+			this.domainType = domainType;
+			this.returnType = returnType;
+			this.collection = collection;
+			this.query = query;
+			this.mapFunction = mapFunction;
+			this.reduceFunction = reduceFunction;
+			this.options = options;
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.TerminatingMapReduce#all()
+		 */
+		@Override
+		public List<T> all() {
+			return template.mapReduce(query, domainType, getCollectionName(), mapFunction, reduceFunction, options,
+					returnType);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithCollection#inCollection(java.lang.String)
+		 */
+		@Override
+		public MapReduceWithProjection<T> inCollection(String collection) {
+
+			Assert.hasText(collection, "Collection name must not be null nor empty!");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithQuery#query(org.springframework.data.mongodb.core.query.Query)
+		 */
+		@Override
+		public TerminatingMapReduce<T> matching(Query query) {
+
+			Assert.notNull(query, "Query must not be null!");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithProjection#as(java.lang.Class)
+		 */
+		@Override
+		public <R> MapReduceWithQuery<R> as(Class<R> resultType) {
+
+			Assert.notNull(resultType, "ResultType must not be null!");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, resultType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithOptions#with(org.springframework.data.mongodb.core.mapreduce.MapReduceOptions)
+		 */
+		@Override
+		public ExecutableMapReduce<T> with(MapReduceOptions options) {
+
+			Assert.notNull(options, "Options must not be null! Please consider empty MapReduceOptions#options() instead.");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithMapFunction#map(java.lang.String)
+		 */
+		@Override
+		public MapReduceWithReduceFunction<T> map(String mapFunction) {
+
+			Assert.hasText(mapFunction, "MapFunction name must not be null nor empty!");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.MapReduceWithReduceFunction#reduce(java.lang.String)
+		 */
+		@Override
+		public ExecutableMapReduce<T> reduce(String reduceFunction) {
+
+			Assert.hasText(reduceFunction, "ReduceFunction name must not be null nor empty!");
+
+			return new ExecutableMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		private String getCollectionName() {
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
+		}
+	}
+}

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

@@ -53,6 +53,37 @@ public interface ExecutableRemoveOperation {
 	 */
 	<T> ExecutableRemove<T> remove(Class<T> domainType);
 
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.0
+	 */
+	interface TerminatingRemove<T> {
+
+		/**
+		 * Remove all documents matching.
+		 *
+		 * @return the {@link DeleteResult}. Never {@literal null}.
+		 */
+		DeleteResult all();
+
+		/**
+		 * Remove the first matching document.
+		 *
+		 * @return the {@link DeleteResult}. Never {@literal null}.
+		 */
+		DeleteResult one();
+
+		/**
+		 * Remove and return all matching documents. <br/>
+		 * <strong>NOTE</strong> The entire list of documents will be fetched before sending the actual delete commands.
+		 * Also, {@link org.springframework.context.ApplicationEvent}s will be published for each and every delete
+		 * operation.
+		 *
+		 * @return empty {@link List} if no match found. Never {@literal null}.
+		 */
+		List<T> findAndRemove();
+	}
+
 	/**
 	 * Collection override (optional).
 	 *
@@ -73,29 +104,6 @@ public interface ExecutableRemoveOperation {
 		RemoveWithQuery<T> inCollection(String collection);
 	}
 
-	/**
-	 * @author Christoph Strobl
-	 * @since 2.0
-	 */
-	interface TerminatingRemove<T> {
-
-		/**
-		 * Remove all documents matching.
-		 *
-		 * @return the {@link DeleteResult}. Never {@literal null}.
-		 */
-		DeleteResult all();
-
-		/**
-		 * Remove and return all matching documents. <br/>
-		 * <strong>NOTE</strong> The entire list of documents will be fetched before sending the actual delete commands.
-		 * Also, {@link org.springframework.context.ApplicationEvent}s will be published for each and every delete
-		 * operation.
-		 *
-		 * @return empty {@link List} if no match found. Never {@literal null}.
-		 */
-		List<T> findAndRemove();
-	}
 
 	/**
 	 * @author Christoph Strobl

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

@@ -36,24 +36,12 @@ import com.mongodb.client.result.DeleteResult;
  * @author Mark Paluch
  * @since 2.0
  */
+@RequiredArgsConstructor
 class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 
 	private static final Query ALL_QUERY = new Query();
 
-	private final MongoTemplate tempate;
-
-	/**
-	 * Create new {@link ExecutableRemoveOperationSupport}.
-	 *
-	 * @param template must not be {@literal null}.
-	 * @throws IllegalArgumentException if template is {@literal null}.
-	 */
-	ExecutableRemoveOperationSupport(MongoTemplate template) {
-
-		Assert.notNull(template, "Template must not be null!");
-
-		this.tempate = template;
-	}
+	private final @NonNull MongoTemplate tempate;
 
 	/*
 	 * (non-Javadoc)
@@ -110,10 +98,16 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 		 */
 		@Override
 		public DeleteResult all() {
+			return template.doRemove(getCollectionName(), query, domainType, true);
+		}
 
-			String collectionName = getCollectionName();
-
-			return template.doRemove(collectionName, query, domainType);
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.TerminatingRemove#one()
+		 */
+		@Override
+		public DeleteResult one() {
+			return template.doRemove(getCollectionName(), query, domainType, false);
 		}
 
 		/*
@@ -129,7 +123,7 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -19,13 +19,13 @@ import java.util.Optional;
 
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
-
-import com.mongodb.client.result.UpdateResult;
 import org.springframework.lang.Nullable;
 
+import com.mongodb.client.result.UpdateResult;
+
 /**
- * {@link ExecutableUpdateOperation} allows creation and execution of MongoDB update / findAndModify operations in a
- * fluent API style. <br />
+ * {@link ExecutableUpdateOperation} allows creation and execution of MongoDB update / findAndModify / findAndReplace
+ * operations in a fluent API style. <br />
  * The starting {@literal domainType} is used for mapping the {@link Query} provided via {@code matching}, as well as
  * the {@link Update} via {@code apply} into the MongoDB specific representations. The collection to operate on is by
  * default derived from the initial {@literal domainType} and can be defined there via
@@ -57,6 +57,91 @@ public interface ExecutableUpdateOperation {
 	 */
 	<T> ExecutableUpdate<T> update(Class<T> domainType);
 
+	/**
+	 * Trigger findAndModify execution by calling one of the terminating methods.
+	 *
+	 * @author Christoph Strobl
+	 * @author Mark Paluch
+	 * @since 2.0
+	 */
+	interface TerminatingFindAndModify<T> {
+
+		/**
+		 * Find, modify and return the first matching document.
+		 *
+		 * @return {@link Optional#empty()} if nothing found.
+		 */
+		default Optional<T> findAndModify() {
+			return Optional.ofNullable(findAndModifyValue());
+		}
+
+		/**
+		 * Find, modify and return the first matching document.
+		 *
+		 * @return {@literal null} if nothing found.
+		 */
+		@Nullable
+		T findAndModifyValue();
+	}
+
+	/**
+	 * Trigger
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * execution by calling one of the terminating methods.
+	 *
+	 * @author Mark Paluch
+	 * @since 2.1
+	 */
+	interface TerminatingFindAndReplace<T> {
+
+		/**
+		 * Find, replace and return the first matching document.
+		 *
+		 * @return {@link Optional#empty()} if nothing found.
+		 */
+		default Optional<T> findAndReplace() {
+			return Optional.ofNullable(findAndReplaceValue());
+		}
+
+		/**
+		 * Find, replace and return the first matching document.
+		 *
+		 * @return {@literal null} if nothing found.
+		 */
+		@Nullable
+		T findAndReplaceValue();
+	}
+
+	/**
+	 * Trigger update execution by calling one of the terminating methods.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.0
+	 */
+	interface TerminatingUpdate<T> extends TerminatingFindAndModify<T>, FindAndModifyWithOptions<T> {
+
+		/**
+		 * Update all matching documents in the collection.
+		 *
+		 * @return never {@literal null}.
+		 */
+		UpdateResult all();
+
+		/**
+		 * Update the first document in the collection.
+		 *
+		 * @return never {@literal null}.
+		 */
+		UpdateResult first();
+
+		/**
+		 * Creates a new document if no documents match the filter query or updates the matching ones.
+		 *
+		 * @return never {@literal null}.
+		 */
+		UpdateResult upsert();
+	}
+
 	/**
 	 * Declare the {@link Update} to apply.
 	 *
@@ -73,6 +158,16 @@ public interface ExecutableUpdateOperation {
 		 * @throws IllegalArgumentException if update is {@literal null}.
 		 */
 		TerminatingUpdate<T> apply(Update update);
+
+		/**
+		 * Specify {@code replacement} object.
+		 *
+		 * @param replacement must not be {@literal null}.
+		 * @return new instance of {@link FindAndReplaceOptions}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
+		 * @since 2.1
+		 */
+		FindAndReplaceWithProjection<T> replaceWith(T replacement);
 	}
 
 	/**
@@ -131,56 +226,43 @@ public interface ExecutableUpdateOperation {
 	}
 
 	/**
-	 * Trigger findAndModify execution by calling one of the terminating methods.
+	 * Define {@link FindAndReplaceOptions}.
+	 *
+	 * @author Mark Paluch
+	 * @author Christoph Strobl
+	 * @since 2.1
 	 */
-	interface TerminatingFindAndModify<T> {
+	interface FindAndReplaceWithOptions<T> extends TerminatingFindAndReplace<T> {
 
 		/**
-		 * Find, modify and return the first matching document.
+		 * Explicitly define {@link FindAndReplaceOptions} for the {@link Update}.
 		 *
-		 * @return {@link Optional#empty()} if nothing found.
+		 * @param options must not be {@literal null}.
+		 * @return new instance of {@link FindAndReplaceOptions}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
 		 */
-		default Optional<T> findAndModify() {
-			return Optional.ofNullable(findAndModifyValue());
-		}
-
-		/**
-		 * Find, modify and return the first matching document.
-		 *
-		 * @return {@literal null} if nothing found.
-		 */
-		@Nullable
-		T findAndModifyValue();
+		FindAndReplaceWithProjection<T> withOptions(FindAndReplaceOptions options);
 	}
 
 	/**
-	 * Trigger update execution by calling one of the terminating methods.
+	 * Result type override (Optional).
 	 *
 	 * @author Christoph Strobl
-	 * @since 2.0
+	 * @since 2.1
 	 */
-	interface TerminatingUpdate<T> extends TerminatingFindAndModify<T>, FindAndModifyWithOptions<T> {
+	interface FindAndReplaceWithProjection<T> extends FindAndReplaceWithOptions<T> {
 
 		/**
-		 * Update all matching documents in the collection.
+		 * Define the target type fields should be mapped to. <br />
+		 * Skip this step if you are anyway only interested in the original domain type.
 		 *
-		 * @return never {@literal null}.
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link FindAndReplaceWithProjection}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
 		 */
-		UpdateResult all();
+		<R> FindAndReplaceWithOptions<R> as(Class<R> resultType);
 
-		/**
-		 * Update the first document in the collection.
-		 *
-		 * @return never {@literal null}.
-		 */
-		UpdateResult first();
-
-		/**
-		 * Creates a new document if no documents match the filter query or updates the matching ones.
-		 *
-		 * @return never {@literal null}.
-		 */
-		UpdateResult upsert();
 	}
 
 	/**

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

@@ -35,23 +35,12 @@ import com.mongodb.client.result.UpdateResult;
  * @author Mark Paluch
  * @since 2.0
  */
+@RequiredArgsConstructor
 class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 	private static final Query ALL_QUERY = new Query();
 
-	private final MongoTemplate template;
-
-	/**
-	 * Creates new {@link ExecutableUpdateOperationSupport}.
-	 *
-	 * @param template must not be {@literal null}.
-	 */
-	ExecutableUpdateOperationSupport(MongoTemplate template) {
-
-		Assert.notNull(template, "Template must not be null!");
-
-		this.template = template;
-	}
+	private final @NonNull MongoTemplate template;
 
 	/*
 	 * (non-Javadoc)
@@ -62,7 +51,7 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 		Assert.notNull(domainType, "DomainType must not be null!");
 
-		return new ExecutableUpdateSupport<>(template, domainType, ALL_QUERY, null, null, null);
+		return new ExecutableUpdateSupport<>(template, domainType, ALL_QUERY, null, null, null, null, null, domainType);
 	}
 
 	/**
@@ -72,14 +61,18 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 	@RequiredArgsConstructor
 	@FieldDefaults(level = AccessLevel.PRIVATE, makeFinal = true)
 	static class ExecutableUpdateSupport<T>
-			implements ExecutableUpdate<T>, UpdateWithCollection<T>, UpdateWithQuery<T>, TerminatingUpdate<T> {
+			implements ExecutableUpdate<T>, UpdateWithCollection<T>, UpdateWithQuery<T>, TerminatingUpdate<T>,
+			FindAndReplaceWithOptions<T>, TerminatingFindAndReplace<T>, FindAndReplaceWithProjection<T> {
 
 		@NonNull MongoTemplate template;
-		@NonNull Class<T> domainType;
+		@NonNull Class domainType;
 		Query query;
 		@Nullable Update update;
 		@Nullable String collection;
-		@Nullable FindAndModifyOptions options;
+		@Nullable FindAndModifyOptions findAndModifyOptions;
+		@Nullable FindAndReplaceOptions findAndReplaceOptions;
+		@Nullable Object replacement;
+		@NonNull Class<T> targetType;
 
 		/*
 		 * (non-Javadoc)
@@ -90,7 +83,8 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 			Assert.notNull(update, "Update must not be null!");
 
-			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, options);
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					findAndReplaceOptions, replacement, targetType);
 		}
 
 		/*
@@ -102,7 +96,8 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 			Assert.hasText(collection, "Collection must not be null nor empty!");
 
-			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, options);
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					findAndReplaceOptions, replacement, targetType);
 		}
 
 		/*
@@ -114,7 +109,34 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 			Assert.notNull(options, "Options must not be null!");
 
-			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, options);
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, options,
+					findAndReplaceOptions, replacement, targetType);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithUpdate#replaceWith(Object)
+		 */
+		@Override
+		public FindAndReplaceWithProjection<T> replaceWith(T replacement) {
+
+			Assert.notNull(replacement, "Replacement must not be null!");
+
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					findAndReplaceOptions, replacement, targetType);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.FindAndReplaceWithOptions#withOptions(org.springframework.data.mongodb.core.FindAndReplaceOptions)
+		 */
+		@Override
+		public FindAndReplaceWithProjection<T> withOptions(FindAndReplaceOptions options) {
+
+			Assert.notNull(options, "Options must not be null!");
+
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					options, replacement, targetType);
 		}
 
 		/*
@@ -126,7 +148,21 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 
 			Assert.notNull(query, "Query must not be null!");
 
-			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, options);
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					findAndReplaceOptions, replacement, targetType);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.FindAndReplaceWithProjection#as(java.lang.Class)
+		 */
+		@Override
+		public <R> FindAndReplaceWithOptions<R> as(Class<R> resultType) {
+
+			Assert.notNull(resultType, "ResultType must not be null!");
+
+			return new ExecutableUpdateSupport<>(template, domainType, query, update, collection, findAndModifyOptions,
+					findAndReplaceOptions, replacement, resultType);
 		}
 
 		/*
@@ -162,7 +198,22 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 		 */
 		@Override
 		public @Nullable T findAndModifyValue() {
-			return template.findAndModify(query, update, options != null ? options : new FindAndModifyOptions(), domainType, getCollectionName());
+
+			return template.findAndModify(query, update,
+					findAndModifyOptions != null ? findAndModifyOptions : new FindAndModifyOptions(), targetType,
+					getCollectionName());
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingFindAndReplace#findAndReplaceValue()
+		 */
+		@Override
+		public @Nullable T findAndReplaceValue() {
+
+			return (T) template.findAndReplace(query, replacement,
+					findAndReplaceOptions != null ? findAndReplaceOptions : FindAndReplaceOptions.empty(), domainType,
+					getCollectionName(), targetType);
 		}
 
 		private UpdateResult doUpdate(boolean multi, boolean upsert) {
@@ -170,7 +221,7 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -36,15 +36,17 @@ public class FindAndModifyOptions {
 	/**
 	 * Static factory method to create a FindAndModifyOptions instance
 	 *
-	 * @return a new instance
+	 * @return new instance of {@link FindAndModifyOptions}.
 	 */
 	public static FindAndModifyOptions options() {
 		return new FindAndModifyOptions();
 	}
 
 	/**
-	 * @param options
-	 * @return
+	 * 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
 	 */
 	public static FindAndModifyOptions of(@Nullable FindAndModifyOptions source) {

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

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+/**
+ * Options for
+ * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>.
+ * <br />
+ * Defaults to
+ * <dl>
+ * <dt>returnNew</dt>
+ * <dd>false</dd>
+ * <dt>upsert</dt>
+ * <dd>false</dd>
+ * </dl>
+ *
+ * @author Mark Paluch
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+public class FindAndReplaceOptions {
+
+	private boolean returnNew;
+	private boolean upsert;
+
+	/**
+	 * Static factory method to create a {@link FindAndReplaceOptions} instance.
+	 * <dl>
+	 * <dt>returnNew</dt>
+	 * <dd>false</dd>
+	 * <dt>upsert</dt>
+	 * <dd>false</dd>
+	 * </dl>
+	 *
+	 * @return new instance of {@link FindAndReplaceOptions}.
+	 */
+	public static FindAndReplaceOptions options() {
+		return new FindAndReplaceOptions();
+	}
+
+	/**
+	 * Static factory method to create a {@link FindAndReplaceOptions} instance with
+	 * <dl>
+	 * <dt>returnNew</dt>
+	 * <dd>false</dd>
+	 * <dt>upsert</dt>
+	 * <dd>false</dd>
+	 * </dl>
+	 *
+	 * @return new instance of {@link FindAndReplaceOptions}.
+	 */
+	public static FindAndReplaceOptions empty() {
+		return new FindAndReplaceOptions();
+	}
+
+	/**
+	 * Return the replacement document.
+	 *
+	 * @return this.
+	 */
+	public FindAndReplaceOptions returnNew() {
+
+		this.returnNew = true;
+		return this;
+	}
+
+	/**
+	 * Insert a new document if not exists.
+	 *
+	 * @return this.
+	 */
+	public FindAndReplaceOptions upsert() {
+
+		this.upsert = true;
+		return this;
+	}
+
+	/**
+	 * Get the bit indicating to return the replacement document.
+	 *
+	 * @return
+	 */
+	public boolean isReturnNew() {
+		return returnNew;
+	}
+
+	/**
+	 * Get the bit indicating if to create a new document if not exists.
+	 *
+	 * @return
+	 */
+	public boolean isUpsert() {
+		return upsert;
+	}
+
+}

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

@@ -22,4 +22,4 @@ package org.springframework.data.mongodb.core;
  * @since 2.0
  */
 public interface FluentMongoOperations extends ExecutableFindOperation, ExecutableInsertOperation,
-		ExecutableUpdateOperation, ExecutableRemoveOperation, ExecutableAggregationOperation {}
+		ExecutableUpdateOperation, ExecutableRemoveOperation, ExecutableAggregationOperation, ExecutableMapReduceOperation {}

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

@@ -20,7 +20,7 @@ import org.springframework.util.Assert;
 
 /**
  * Value object to mitigate different representations of geo command execution results in MongoDB.
- * 
+ *
  * @author Oliver Gierke
  * @author Christoph Strobl
  * @soundtrack Fruitcake - Jeff Coffin (The Inside of the Outside)
@@ -34,7 +34,7 @@ class GeoCommandStatistics {
 
 	/**
 	 * Creates a new {@link GeoCommandStatistics} instance with the given source document.
-	 * 
+	 *
 	 * @param source must not be {@literal null}.
 	 */
 	private GeoCommandStatistics(Document source) {
@@ -45,7 +45,7 @@ class GeoCommandStatistics {
 
 	/**
 	 * Creates a new {@link GeoCommandStatistics} from the given command result extracting the statistics.
-	 * 
+	 *
 	 * @param commandResult must not be {@literal null}.
 	 * @return
 	 */
@@ -60,7 +60,7 @@ class GeoCommandStatistics {
 	/**
 	 * Returns the average distance reported by the command result. Mitigating a removal of the field in case the command
 	 * didn't return any result introduced in MongoDB 3.2 RC1.
-	 * 
+	 *
 	 * @return
 	 * @see <a href="https://jira.mongodb.org/browse/SERVER-21024">MongoDB Jira SERVER-21024</a>
 	 */

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

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.bson.Document;
+import org.bson.conversions.Bson;
+import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.core.query.UpdateDefinition;
+import org.springframework.data.util.StreamUtils;
+
+import com.mongodb.client.model.Filters;
+
+/**
+ * A MongoDB document in its mapped state. I.e. after a source document has been mapped using mapping information of the
+ * entity the source document was supposed to represent.
+ *
+ * @author Oliver Gierke
+ * @since 2.1
+ */
+@RequiredArgsConstructor(staticName = "of")
+public class MappedDocument {
+
+	private static final String ID_FIELD = "_id";
+	private static final Document ID_ONLY_PROJECTION = new Document(ID_FIELD, 1);
+
+	private final @Getter Document document;
+
+	public static Document getIdOnlyProjection() {
+		return ID_ONLY_PROJECTION;
+	}
+
+	public static Document getIdIn(Collection<?> ids) {
+		return new Document(ID_FIELD, new Document("$in", ids));
+	}
+
+	public static List<Object> toIds(Collection<Document> documents) {
+
+		return documents.stream()//
+				.map(it -> it.get(ID_FIELD))//
+				.collect(StreamUtils.toUnmodifiableList());
+	}
+
+	public boolean hasId() {
+		return document.containsKey(ID_FIELD);
+	}
+
+	public boolean hasNonNullId() {
+		return hasId() && document.get(ID_FIELD) != null;
+	}
+
+	public Object getId() {
+		return document.get(ID_FIELD);
+	}
+
+	public <T> T getId(Class<T> type) {
+		return document.get(ID_FIELD, type);
+	}
+
+	public boolean isIdPresent(Class<?> type) {
+		return type.isInstance(getId());
+	}
+
+	public Bson getIdFilter() {
+		return Filters.eq(ID_FIELD, document.get(ID_FIELD));
+	}
+
+	public UpdateDefinition updateWithoutId() {
+		return new MappedUpdate(Update.fromDocument(document, ID_FIELD));
+	}
+
+	/**
+	 * An {@link UpdateDefinition} that indicates that the {@link #getUpdateObject() update object} has already been
+	 * mapped to the specific domain type.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1.4
+	 */
+	class MappedUpdate implements UpdateDefinition {
+
+		private final Update delegate;
+
+		MappedUpdate(Update delegate) {
+			this.delegate = delegate;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#getUpdateObject()
+		 */
+		@Override
+		public Document getUpdateObject() {
+			return delegate.getUpdateObject();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#modifies(java.lang.String)
+		 */
+		@Override
+		public boolean modifies(String key) {
+			return delegate.modifies(key);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#inc(java.lang.String)
+		 */
+		@Override
+		public void inc(String version) {
+			delegate.inc(version);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#isIsolated()
+		 */
+		@Override
+		public Boolean isIsolated() {
+			return delegate.isIsolated();
+		}
+	}
+}

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

@@ -29,7 +29,7 @@ import com.mongodb.WriteConcern;
  * <li>REMOVE has null document</li>
  * <li>INSERT_LIST has null entityType, document, and query</li>
  * </ul>
- * 
+ *
  * @author Mark Pollack
  * @author Oliver Gierke
  * @author Christoph Strobl
@@ -46,7 +46,7 @@ public class MongoAction {
 
 	/**
 	 * Create an instance of a {@link MongoAction}.
-	 * 
+	 *
 	 * @param defaultWriteConcern the default write concern. Can be {@literal null}.
 	 * @param mongoActionOperation action being taken against the collection. Must not be {@literal null}.
 	 * @param collectionName the collection name, must not be {@literal null} or empty.

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

@@ -18,7 +18,7 @@ package org.springframework.data.mongodb.core;
 /**
  * Enumeration for operations on a collection. Used with {@link MongoAction} to help determine the WriteConcern to use
  * for a given mutating operation
- * 
+ *
  * @author Mark Pollack
  * @author Oliver Gierke
  * @see MongoAction

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

@@ -25,7 +25,7 @@ import com.mongodb.client.MongoDatabase;
 
 /**
  * Mongo server administration exposed via JMX annotations
- * 
+ *
  * @author Mark Pollack
  * @author Thomas Darimont
  * @author Mark Paluch

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

@@ -23,7 +23,7 @@ import com.mongodb.WriteResult;
 
 /**
  * Mongo-specific {@link DataIntegrityViolationException}.
- * 
+ *
  * @author Oliver Gierke
  */
 public class MongoDataIntegrityViolationException extends DataIntegrityViolationException {
@@ -35,7 +35,7 @@ public class MongoDataIntegrityViolationException extends DataIntegrityViolation
 
 	/**
 	 * Creates a new {@link MongoDataIntegrityViolationException} using the given message and {@link WriteResult}.
-	 * 
+	 *
 	 * @param message the exception message
 	 * @param writeResult the {@link WriteResult} that causes the exception, must not be {@literal null}.
 	 * @param actionOperation the {@link MongoActionOperation} that caused the exception, must not be {@literal null}.
@@ -54,7 +54,7 @@ public class MongoDataIntegrityViolationException extends DataIntegrityViolation
 
 	/**
 	 * Returns the {@link WriteResult} that caused the exception.
-	 * 
+	 *
 	 * @return the writeResult
 	 */
 	public WriteResult getWriteResult() {
@@ -63,7 +63,7 @@ public class MongoDataIntegrityViolationException extends DataIntegrityViolation
 
 	/**
 	 * Returns the {@link MongoActionOperation} in which the current exception occured.
-	 * 
+	 *
 	 * @return the actionOperation
 	 */
 	public MongoActionOperation getActionOperation() {

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

@@ -0,0 +1,272 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.Value;
+
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.dao.DataAccessException;
+import org.springframework.dao.support.PersistenceExceptionTranslator;
+import org.springframework.data.mongodb.MongoDbFactory;
+import org.springframework.data.mongodb.SessionAwareMethodInterceptor;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+import com.mongodb.ClientSessionOptions;
+import com.mongodb.DB;
+import com.mongodb.WriteConcern;
+import com.mongodb.client.ClientSession;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoDatabase;
+
+/**
+ * Common base class for usage with both {@link com.mongodb.client.MongoClients} and {@link com.mongodb.MongoClient}
+ * defining common properties such as database name and exception translator.
+ * <p/>
+ * Not intended to be used directly.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @param <C> Client type.
+ * @since 2.1
+ * @see SimpleMongoDbFactory
+ * @see SimpleMongoClientDbFactory
+ */
+public abstract class MongoDbFactorySupport<C> implements MongoDbFactory {
+
+	private final C mongoClient;
+	private final String databaseName;
+	private final boolean mongoInstanceCreated;
+	private final PersistenceExceptionTranslator exceptionTranslator;
+
+	private @Nullable WriteConcern writeConcern;
+
+	/**
+	 * Create a new {@link MongoDbFactorySupport} object given {@code mongoClient}, {@code databaseName},
+	 * {@code mongoInstanceCreated} and {@link PersistenceExceptionTranslator}.
+	 * 
+	 * @param mongoClient must not be {@literal null}.
+	 * @param databaseName must not be {@literal null} or empty.
+	 * @param mongoInstanceCreated {@literal true} if the client instance was created by a subclass of
+	 *          {@link MongoDbFactorySupport} to close the client on {@link #destroy()}.
+	 * @param exceptionTranslator must not be {@literal null}.
+	 */
+	protected MongoDbFactorySupport(C mongoClient, String databaseName, boolean mongoInstanceCreated,
+			PersistenceExceptionTranslator exceptionTranslator) {
+
+		Assert.notNull(mongoClient, "MongoClient must not be null!");
+		Assert.hasText(databaseName, "Database name must not be empty!");
+		Assert.isTrue(databaseName.matches("[^/\\\\.$\"\\s]+"),
+				"Database name must not contain slashes, dots, spaces, quotes, or dollar signs!");
+
+		this.mongoClient = mongoClient;
+		this.databaseName = databaseName;
+		this.mongoInstanceCreated = mongoInstanceCreated;
+		this.exceptionTranslator = exceptionTranslator;
+	}
+
+	/**
+	 * Configures the {@link WriteConcern} to be used on the {@link MongoDatabase} instance being created.
+	 *
+	 * @param writeConcern the writeConcern to set
+	 */
+	public void setWriteConcern(WriteConcern writeConcern) {
+		this.writeConcern = writeConcern;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.MongoDbFactory#getDb()
+	 */
+	public MongoDatabase getDb() throws DataAccessException {
+		return getDb(databaseName);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.MongoDbFactory#getDb(java.lang.String)
+	 */
+	@Override
+	public MongoDatabase getDb(String dbName) throws DataAccessException {
+
+		Assert.hasText(dbName, "Database name must not be empty!");
+
+		MongoDatabase db = doGetMongoDatabase(dbName);
+
+		if (writeConcern == null) {
+			return db;
+		}
+
+		return db.withWriteConcern(writeConcern);
+	}
+
+	/**
+	 * Get the actual {@link MongoDatabase} from the client.
+	 * 
+	 * @param dbName must not be {@literal null} or empty.
+	 * @return
+	 */
+	protected abstract MongoDatabase doGetMongoDatabase(String dbName);
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.DisposableBean#destroy()
+	 */
+	public void destroy() throws Exception {
+		if (mongoInstanceCreated) {
+			closeClient();
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.MongoDbFactory#getExceptionTranslator()
+	 */
+	public PersistenceExceptionTranslator getExceptionTranslator() {
+		return this.exceptionTranslator;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.MongoDbFactory#withSession(com.mongodb.session.Session)
+	 */
+	public MongoDbFactory withSession(ClientSession session) {
+		return new MongoDbFactorySupport.ClientSessionBoundMongoDbFactory(session, this);
+	}
+
+	/**
+	 * Close the client instance.
+	 */
+	protected abstract void closeClient();
+
+	/**
+	 * @return the Mongo client object.
+	 */
+	protected C getMongoClient() {
+		return mongoClient;
+	}
+
+	/**
+	 * @return the database name.
+	 */
+	protected String getDefaultDatabaseName() {
+		return databaseName;
+	}
+
+	/**
+	 * {@link ClientSession} bound {@link MongoDbFactory} decorating the database with a
+	 * {@link SessionAwareMethodInterceptor}.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	@Value
+	static class ClientSessionBoundMongoDbFactory implements MongoDbFactory {
+
+		ClientSession session;
+		MongoDbFactory delegate;
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#getDb()
+		 */
+		@Override
+		public MongoDatabase getDb() throws DataAccessException {
+			return proxyMongoDatabase(delegate.getDb());
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#getDb(java.lang.String)
+		 */
+		@Override
+		public MongoDatabase getDb(String dbName) throws DataAccessException {
+			return proxyMongoDatabase(delegate.getDb(dbName));
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#getExceptionTranslator()
+		 */
+		@Override
+		public PersistenceExceptionTranslator getExceptionTranslator() {
+			return delegate.getExceptionTranslator();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#getLegacyDb()
+		 */
+		@Override
+		public DB getLegacyDb() {
+			return delegate.getLegacyDb();
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#getSession(com.mongodb.ClientSessionOptions)
+		 */
+		@Override
+		public ClientSession getSession(ClientSessionOptions options) {
+			return delegate.getSession(options);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#withSession(com.mongodb.session.ClientSession)
+		 */
+		@Override
+		public MongoDbFactory withSession(ClientSession session) {
+			return delegate.withSession(session);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.MongoDbFactory#isTransactionActive()
+		 */
+		@Override
+		public boolean isTransactionActive() {
+			return session != null && session.hasActiveTransaction();
+		}
+
+		private MongoDatabase proxyMongoDatabase(MongoDatabase database) {
+			return createProxyInstance(session, database, MongoDatabase.class);
+		}
+
+		private MongoDatabase proxyDatabase(com.mongodb.session.ClientSession session, MongoDatabase database) {
+			return createProxyInstance(session, database, MongoDatabase.class);
+		}
+
+		private MongoCollection<?> proxyCollection(com.mongodb.session.ClientSession session,
+				MongoCollection<?> collection) {
+			return createProxyInstance(session, collection, MongoCollection.class);
+		}
+
+		private <T> T createProxyInstance(com.mongodb.session.ClientSession session, T target, Class<T> targetType) {
+
+			ProxyFactory factory = new ProxyFactory();
+			factory.setTarget(target);
+			factory.setInterfaces(targetType);
+			factory.setOpaque(true);
+
+			factory.addAdvice(new SessionAwareMethodInterceptor<>(session, target, ClientSession.class, MongoDatabase.class,
+					this::proxyDatabase, MongoCollection.class, this::proxyCollection));
+
+			return targetType.cast(factory.getProxy());
+		}
+	}
+
+}

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

@@ -30,6 +30,8 @@ import org.springframework.dao.InvalidDataAccessResourceUsageException;
 import org.springframework.dao.PermissionDeniedDataAccessException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.BulkOperationException;
+import org.springframework.data.mongodb.ClientSessionException;
+import org.springframework.data.mongodb.MongoTransactionException;
 import org.springframework.data.mongodb.UncategorizedMongoDbException;
 import org.springframework.data.mongodb.util.MongoDbErrorCodes;
 import org.springframework.lang.Nullable;
@@ -45,7 +47,7 @@ import com.mongodb.bulk.BulkWriteError;
  * Simple {@link PersistenceExceptionTranslator} for Mongo. Convert the given runtime exception to an appropriate
  * exception from the {@code org.springframework.dao} hierarchy. Return {@literal null} if no translation is
  * appropriate: any other exception may have resulted from user code, and should not be translated.
- * 
+ *
  * @author Oliver Gierke
  * @author Michal Vich
  * @author Christoph Strobl
@@ -120,18 +122,32 @@ public class MongoExceptionTranslator implements PersistenceExceptionTranslator
 			int code = ((MongoException) ex).getCode();
 
 			if (MongoDbErrorCodes.isDuplicateKeyCode(code)) {
-				throw new DuplicateKeyException(ex.getMessage(), ex);
+				return new DuplicateKeyException(ex.getMessage(), ex);
 			} else if (MongoDbErrorCodes.isDataAccessResourceFailureCode(code)) {
-				throw new DataAccessResourceFailureException(ex.getMessage(), ex);
+				return new DataAccessResourceFailureException(ex.getMessage(), ex);
 			} else if (MongoDbErrorCodes.isInvalidDataAccessApiUsageCode(code) || code == 10003 || code == 12001
 					|| code == 12010 || code == 12011 || code == 12012) {
-				throw new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
+				return new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
 			} else if (MongoDbErrorCodes.isPermissionDeniedCode(code)) {
-				throw new PermissionDeniedDataAccessException(ex.getMessage(), ex);
+				return new PermissionDeniedDataAccessException(ex.getMessage(), ex);
+			} else if (MongoDbErrorCodes.isClientSessionFailureCode(code)) {
+				return new ClientSessionException(ex.getMessage(), ex);
+			} else if (MongoDbErrorCodes.isTransactionFailureCode(code)) {
+				return new MongoTransactionException(ex.getMessage(), ex);
 			}
 			return new UncategorizedMongoDbException(ex.getMessage(), ex);
 		}
 
+		// may interfere with OmitStackTraceInFastThrow (enabled by default).
+		// see https://jira.spring.io/browse/DATAMONGO-1905
+		if (ex instanceof IllegalStateException) {
+			for (StackTraceElement elm : ex.getStackTrace()) {
+				if (elm.getClassName().contains("ClientSession")) {
+					return new ClientSessionException(ex.getMessage(), ex);
+				}
+			}
+		}
+
 		// If we get here, we have an exception that resulted from user code,
 		// rather than the persistence provider, so we return null to indicate
 		// that translation should not occur.

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

@@ -18,6 +18,8 @@ package org.springframework.data.mongodb.core;
 import java.util.Collection;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
 
 import org.bson.Document;
 import org.springframework.data.geo.GeoResults;
@@ -26,6 +28,7 @@ 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.TypedAggregation;
+import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.core.index.IndexOperations;
 import org.springframework.data.mongodb.core.mapreduce.GroupBy;
@@ -39,9 +42,13 @@ import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
 import org.springframework.data.util.CloseableIterator;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
+import com.mongodb.ClientSessionOptions;
 import com.mongodb.Cursor;
 import com.mongodb.ReadPreference;
+import com.mongodb.client.ClientSession;
 import com.mongodb.client.MongoCollection;
 import com.mongodb.client.result.DeleteResult;
 import com.mongodb.client.result.UpdateResult;
@@ -50,6 +57,10 @@ 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 />
+ * <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>.
  *
  * @author Thomas Risberg
  * @author Mark Pollack
@@ -151,6 +162,64 @@ public interface MongoOperations extends FluentMongoOperations {
 	@Nullable
 	<T> T execute(String collectionName, CollectionCallback<T> action);
 
+	/**
+	 * Obtain a {@link ClientSession session} bound instance of {@link SessionScoped} binding a new {@link ClientSession}
+	 * with given {@literal sessionOptions} to each and every command issued against MongoDB.
+	 *
+	 * @param sessionOptions must not be {@literal null}.
+	 * @return new instance of {@link SessionScoped}. Never {@literal null}.
+	 * @since 2.1
+	 */
+	SessionScoped withSession(ClientSessionOptions sessionOptions);
+
+	/**
+	 * 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 />
+	 * <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}.
+	 *
+	 * @param sessionProvider must not be {@literal null}.
+	 * @since 2.1
+	 */
+	default SessionScoped withSession(Supplier<ClientSession> sessionProvider) {
+
+		Assert.notNull(sessionProvider, "SessionProvider must not be null!");
+
+		return new SessionScoped() {
+
+			private final Object lock = new Object();
+			private @Nullable ClientSession session = null;
+
+			@Override
+			public <T> T execute(SessionCallback<T> action, Consumer<ClientSession> onComplete) {
+
+				synchronized (lock) {
+					if (session == null) {
+						session = sessionProvider.get();
+					}
+				}
+
+				try {
+					return action.doInSession(MongoOperations.this.withSession(session));
+				} finally {
+					onComplete.accept(session);
+				}
+			}
+		};
+	}
+
+	/**
+	 * Obtain a {@link ClientSession} bound instance of {@link MongoOperations}.
+	 * <p />
+	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle.
+	 *
+	 * @param session must not be {@literal null}.
+	 * @return {@link ClientSession} bound instance of {@link MongoOperations}.
+	 * @since 2.1
+	 */
+	MongoOperations withSession(ClientSession session);
+
 	/**
 	 * Executes the given {@link Query} on the entity collection of the specified {@code entityType} backed by a Mongo DB
 	 * {@link Cursor}.
@@ -224,12 +293,15 @@ public interface MongoOperations extends FluentMongoOperations {
 	Set<String> getCollectionNames();
 
 	/**
-	 * Get a collection by name, creating it if it doesn't exist.
+	 * Get a {@link MongoCollection} by its name. The returned collection may not exists yet (except in local memory) and
+	 * is created on first interaction with the server. Collections can be explicitly created via
+	 * {@link #createCollection(Class)}. Please make sure to check if the collection {@link #collectionExists(Class)
+	 * exists} first.
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection. Must not be {@literal null}.
-	 * @return an existing collection or a newly created one.
+	 * @return an existing collection or one created on first server interaction.
 	 */
 	MongoCollection<Document> getCollection(String collectionName);
 
@@ -318,7 +390,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Returns a new {@link BulkOperations} for the given entity type and collection name.
 	 *
 	 * @param mode the {@link BulkMode} to use for bulk operations, must not be {@literal null}.
-	 * @param entityClass the name of the entity class. Can be {@literal null}.
+	 * @param entityType the name of the entity class. Can be {@literal null}.
 	 * @param collectionName the name of the collection to work on, must not be {@literal null} or empty.
 	 * @return {@link BulkOperations} on the named collection associated with the given entity class.
 	 */
@@ -357,8 +429,6 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Execute a group operation over the entire collection. The group operation entity class should match the 'shape' of
 	 * the returned object that takes int account the initial document structure as well as any finalize functions.
 	 *
-	 * @param criteria The criteria that restricts the row that are considered for grouping. If not specified all rows are
-	 *          considered.
 	 * @param inputCollectionName the collection where the group operation will read from
 	 * @param groupBy the conditions under which the group operation will be performed, e.g. keys, initial document,
 	 *          reduce function.
@@ -710,8 +780,67 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findById(Object id, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify
-	 * <a/> to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link List}.
+	 *
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param entityClass the domain type used for determining the actual {@link MongoCollection}. Must not be
+	 *          {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	default <T> List<T> findDistinct(String field, Class<?> entityClass, Class<T> resultClass) {
+		return findDistinct(new Query(), field, entityClass, resultClass);
+	}
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link List}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param entityClass the domain type used for determining the actual {@link MongoCollection} and mapping the
+	 *          {@link Query} to the domain type fields. Must not be {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> List<T> findDistinct(Query query, String field, Class<?> entityClass, Class<T> resultClass);
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link List}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param collectionName the explicit name of the actual {@link MongoCollection}. Must not be {@literal null}.
+	 * @param entityClass the domain type used for mapping the {@link Query} to the domain type fields.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> List<T> findDistinct(Query query, String field, String collectionName, Class<?> entityClass,
+			Class<T> resultClass);
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link List}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param collection the explicit name of the actual {@link MongoCollection}. Must not be {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	default <T> List<T> findDistinct(Query query, String field, String collection, Class<T> resultClass) {
+		return findDistinct(query, field, collection, Object.class, resultClass);
+	}
+
+	/**
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @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}.
@@ -723,8 +852,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, Update update, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify
-	 * <a/> to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @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}.
@@ -737,8 +866,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, Update update, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify
-	 * <a/> to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
@@ -754,8 +883,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify
-	 * <a/> to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
@@ -772,6 +901,167 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
 			String collectionName);
 
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement}
+	 * document. <br />
+	 * The collection name is derived from the {@literal replacement} type. <br />
+	 * Options are defaulted to {@link FindAndReplaceOptions#empty()}. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@literal null}, if not found.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <T> T findAndReplace(Query query, T replacement) {
+		return findAndReplace(query, replacement, FindAndReplaceOptions.empty());
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement}
+	 * document.<br />
+	 * Options are defaulted to {@link FindAndReplaceOptions#empty()}. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. 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.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <T> T findAndReplace(Query query, T replacement, String collectionName) {
+		return findAndReplace(query, replacement, FindAndReplaceOptions.empty(), collectionName);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account.<br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <T> T findAndReplace(Query query, T replacement, FindAndReplaceOptions options) {
+		return findAndReplace(query, replacement, options, getCollectionName(ClassUtils.getUserClass(replacement)));
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account.<br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <T> T findAndReplace(Query query, T replacement, FindAndReplaceOptions options, String collectionName) {
+
+		Assert.notNull(replacement, "Replacement must not be null!");
+		return findAndReplace(query, replacement, options, (Class<T>) ClassUtils.getUserClass(replacement), collectionName);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account.<br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType 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 FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <T> T findAndReplace(Query query, T replacement, FindAndReplaceOptions options, Class<T> entityType,
+			String collectionName) {
+
+		return findAndReplace(query, replacement, options, entityType, collectionName, entityType);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account.<br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType the type used for mapping the {@link Query} to domain type fields and deriving the collection
+	 *          from. Must not be {@literal null}.
+	 * @param resultType the parametrized type projection return type. Must not be {@literal null}, use the domain type of
+	 *          {@code Object.class} instead.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	@Nullable
+	default <S, T> T findAndReplace(Query query, S replacement, FindAndReplaceOptions options, Class<S> entityType,
+			Class<T> resultType) {
+
+		return findAndReplace(query, replacement, options, entityType,
+				getCollectionName(ClassUtils.getUserClass(entityType)), resultType);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account.<br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType the type used for mapping the {@link Query} to domain type fields. Must not be {@literal null}.
+	 * @param collectionName the collection to query. Must not be {@literal null}.
+	 * @param resultType the parametrized type projection return type. Must not be {@literal null}, use the domain type of
+	 *          {@code Object.class} instead.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	@Nullable
+	<S, T> T findAndReplace(Query query, S replacement, FindAndReplaceOptions options, Class<S> entityType,
+			String collectionName, Class<T> resultType);
+
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity type to a single instance of an object of the
 	 * specified type. The first document that matches the query is returned and also removed from the collection in the
@@ -851,15 +1141,16 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * If you 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="http://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
+	 * <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.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @return the inserted object.
 	 */
-	void insert(Object objectToSave);
+	<T> T insert(T objectToSave);
 
 	/**
 	 * Insert the object into the specified collection.
@@ -871,32 +1162,36 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the inserted object.
 	 */
-	void insert(Object objectToSave, String collectionName);
+	<T> T insert(T objectToSave, String collectionName);
 
 	/**
 	 * Insert a Collection of objects into a collection in a single batch write to the database.
 	 *
 	 * @param batchToSave the batch of objects to save. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the inserted objects that.
 	 */
-	void insert(Collection<? extends Object> batchToSave, Class<?> entityClass);
+	<T> Collection<T> insert(Collection<? extends T> batchToSave, Class<?> entityClass);
 
 	/**
 	 * Insert a batch of objects into the specified collection in a single batch write to the database.
 	 *
 	 * @param batchToSave the list of objects to save. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the inserted objects that.
 	 */
-	void insert(Collection<? extends Object> batchToSave, String collectionName);
+	<T> Collection<T> insert(Collection<? extends T> batchToSave, String collectionName);
 
 	/**
 	 * Insert a mixed Collection of objects into a database collection determining the collection name to use based on the
 	 * class.
 	 *
 	 * @param objectsToSave the list of objects to save. Must not be {@literal null}.
+	 * @return the inserted objects.
 	 */
-	void insertAll(Collection<? extends Object> objectsToSave);
+	<T> Collection<T> insertAll(Collection<? extends T> objectsToSave);
 
 	/**
 	 * Save the object to the collection for the entity type of the object to save. This will perform an insert if the
@@ -908,12 +1203,13 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * If you 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="http://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's Type
+	 * <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.
 	 */
-	void save(Object objectToSave);
+	<T> T save(T objectToSave);
 
 	/**
 	 * Save the object to the specified collection. This will perform an insert if the object is not already present, that
@@ -925,13 +1221,14 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * If you 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
-	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type
+	 * 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}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
-	void save(Object objectToSave, String collectionName);
+	<T> T save(T objectToSave, String collectionName);
 
 	/**
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by

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

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+
+import org.bson.Document;
+import org.springframework.data.mapping.SimplePropertyHandler;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.projection.ProjectionFactory;
+import org.springframework.data.projection.ProjectionInformation;
+import org.springframework.util.ClassUtils;
+
+/**
+ * Common operations performed on properties of an entity like extracting fields information for projection creation.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+@RequiredArgsConstructor(access = AccessLevel.PACKAGE)
+class PropertyOperations {
+
+	private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+
+	/**
+	 * For cases where {@code fields} is {@link Document#isEmpty() empty} include only fields that are required for
+	 * creating the projection (target) type if the {@code targetType} is a {@literal DTO projection} or a
+	 * {@literal closed interface projection}.
+	 *
+	 * @param projectionFactory must not be {@literal null}.
+	 * @param fields must not be {@literal null}.
+	 * @param domainType must not be {@literal null}.
+	 * @param targetType must not be {@literal null}.
+	 * @return {@link Document} with fields to be included.
+	 */
+	Document computeFieldsForProjection(ProjectionFactory projectionFactory, Document fields, Class<?> domainType,
+			Class<?> targetType) {
+
+		if (!fields.isEmpty() || ClassUtils.isAssignable(domainType, targetType)) {
+			return fields;
+		}
+
+		Document projectedFields = new Document();
+
+		if (targetType.isInterface()) {
+
+			ProjectionInformation projectionInformation = projectionFactory.getProjectionInformation(targetType);
+
+			if (projectionInformation.isClosed()) {
+				projectionInformation.getInputProperties().forEach(it -> projectedFields.append(it.getName(), 1));
+			}
+		} else {
+			mappingContext.getRequiredPersistentEntity(targetType).doWithProperties(
+					(SimplePropertyHandler) persistentProperty -> projectedFields.append(persistentProperty.getName(), 1));
+		}
+
+		return projectedFields;
+	}
+}

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

@@ -116,11 +116,11 @@ class ReactiveAggregationOperationSupport implements ReactiveAggregationOperatio
 				TypedAggregation<?> typedAggregation = (TypedAggregation<?>) aggregation;
 
 				if (typedAggregation.getInputType() != null) {
-					return template.determineCollectionName(typedAggregation.getInputType());
+					return template.getCollectionName(typedAggregation.getInputType());
 				}
 			}
 
-			return template.determineCollectionName(domainType);
+			return template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -30,5 +30,4 @@ import com.mongodb.reactivestreams.client.MongoCollection;
 public interface ReactiveCollectionCallback<T> {
 
 	Publisher<T> doInCollection(MongoCollection<Document> collection) throws MongoException, DataAccessException;
-
 }

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

@@ -85,6 +85,23 @@ public interface ReactiveFindOperation {
 		 */
 		Flux<T> all();
 
+		/**
+		 * Get all matching elements using a {@link com.mongodb.CursorType#TailableAwait tailable cursor}. 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 either the query returns no match or the cursor returns the
+		 * document at the "end" of the collection and then the application deletes that document.
+		 * <p />
+		 * A stream that is no longer in use must be {@link reactor.core.Disposable#dispose()} disposed} otherwise the
+		 * streams will linger and exhaust resources. <br/>
+		 * <strong>NOTE:</strong> Requires a capped collection.
+		 *
+		 * @return the {@link Flux} emitting converted objects.
+		 * @since 2.1
+		 */
+		Flux<T> tail();
+
 		/**
 		 * Get the number of matching elements.
 		 *
@@ -156,7 +173,7 @@ public interface ReactiveFindOperation {
 	/**
 	 * Result type override (optional).
 	 */
-	interface FindWithProjection<T> extends FindWithQuery<T> {
+	interface FindWithProjection<T> extends FindWithQuery<T>, FindDistinct {
 
 		/**
 		 * Define the target type fields should be mapped to. <br />
@@ -170,8 +187,101 @@ public interface ReactiveFindOperation {
 		<R> FindWithQuery<R> as(Class<R> resultType);
 	}
 
+	/**
+	 * Distinct Find support.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface FindDistinct {
+
+		/**
+		 * Finds the distinct values for a specified {@literal field} across a single
+		 * {@link com.mongodb.reactivestreams.client.MongoCollection} or view.
+		 *
+		 * @param field name of the field. Must not be {@literal null}.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if field is {@literal null}.
+		 */
+		TerminatingDistinct<Object> distinct(String field);
+	}
+
+	/**
+	 * Result type override. Optional.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface DistinctWithProjection {
+
+		/**
+		 * Define the target type the result should be mapped to. <br />
+		 * Skip this step if you are anyway fine with the default conversion.
+		 * <dl>
+		 * <dt>{@link Object} (the default)</dt>
+		 * <dd>Result is mapped according to the {@link org.bson.BsonType} converting eg. {@link org.bson.BsonString} into
+		 * plain {@link String}, {@link org.bson.BsonInt64} to {@link Long}, etc. always picking the most concrete type with
+		 * respect to the domain types property.<br />
+		 * Any {@link org.bson.BsonType#DOCUMENT} is run through the {@link org.springframework.data.convert.EntityReader}
+		 * to obtain the domain type. <br />
+		 * Using {@link Object} also works for non strictly typed fields. Eg. a mixture different types like fields using
+		 * {@link String} in one {@link org.bson.Document} while {@link Long} in another.</dd>
+		 * <dt>Any Simple type like {@link String}, {@link Long}, ...</dt>
+		 * <dd>The result is mapped directly by the MongoDB Java driver and the {@link org.bson.codecs.CodeCodec Codecs} in
+		 * place. This works only for results where all documents considered for the operation use the very same type for
+		 * the field.</dd>
+		 * <dt>Any Domain type</dt>
+		 * <dd>Domain types can only be mapped if the if the result of the actual {@code distinct()} operation returns
+		 * {@link org.bson.BsonType#DOCUMENT}.</dd>
+		 * <dt>{@link org.bson.BsonValue}</dt>
+		 * <dd>Using {@link org.bson.BsonValue} allows retrieval of the raw driver specific format, which returns eg.
+		 * {@link org.bson.BsonString}.</dd>
+		 * </dl>
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> TerminatingDistinct<R> as(Class<R> resultType);
+	}
+
+	/**
+	 * Result restrictions. Optional.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface DistinctWithQuery<T> extends DistinctWithProjection {
+
+		/**
+		 * Set the filter query to be used.
+		 *
+		 * @param query must not be {@literal null}.
+		 * @return new instance of {@link TerminatingDistinct}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		TerminatingDistinct<T> matching(Query query);
+	}
+
+	/**
+	 * Terminating distinct find operations.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface TerminatingDistinct<T> extends DistinctWithQuery<T> {
+
+		/**
+		 * Get all matching distinct field values.
+		 *
+		 * @return empty {@link Flux} if not match found. Never {@literal null}.
+		 */
+		Flux<T> all();
+	}
+
 	/**
 	 * {@link ReactiveFind} provides methods for constructing lookup operations in a fluent way.
 	 */
-	interface ReactiveFind<T> extends FindWithCollection<T>, FindWithProjection<T> {}
+	interface ReactiveFind<T> extends FindWithCollection<T>, FindWithProjection<T>, FindDistinct {}
 }

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

@@ -19,7 +19,6 @@ import lombok.AccessLevel;
 import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.FieldDefaults;
-import org.springframework.lang.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -28,6 +27,7 @@ import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.SerializationUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -169,6 +169,15 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return doFind(null);
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#tail()
+		 */
+		@Override
+		public Flux<T> tail() {
+			return doFind(template.new TailingQueryFindPublisherPreparer(query, domainType));
+		}
+
 		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.FindWithQuery#near(org.springframework.data.mongodb.core.query.NearQuery)
@@ -196,6 +205,18 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return template.exists(query, domainType, getCollectionName());
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.FindDistinct#distinct(java.lang.String)
+		 */
+		@Override
+		public TerminatingDistinct<Object> distinct(String field) {
+
+			Assert.notNull(field, "Field must not be null!");
+
+			return new DistinctOperationSupport<>(this, field);
+		}
+
 		private Flux<T> doFind(@Nullable FindPublisherPreparer preparer) {
 
 			Document queryObject = query.getQueryObject();
@@ -205,16 +226,73 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 					preparer != null ? preparer : getCursorPreparer(query));
 		}
 
+		@SuppressWarnings("unchecked")
+		private Flux<T> doFindDistinct(String field) {
+
+			return template.findDistinct(query, field, getCollectionName(), domainType,
+					returnType == domainType ? (Class<T>) Object.class : returnType);
+		}
+
 		private FindPublisherPreparer getCursorPreparer(Query query) {
 			return template.new QueryFindPublisherPreparer(query, domainType);
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 
 		private String asString() {
 			return SerializationUtils.serializeToJsonSafely(query);
 		}
+
+		/**
+		 * @author Christoph Strobl
+		 * @since 2.1
+		 */
+		static class DistinctOperationSupport<T> implements TerminatingDistinct<T> {
+
+			private final String field;
+			private final ReactiveFindSupport delegate;
+
+			public DistinctOperationSupport(ReactiveFindSupport delegate, String field) {
+
+				this.delegate = delegate;
+				this.field = field;
+			}
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.DistinctWithProjection#as(java.lang.Class)
+			 */
+			@Override
+			public <R> TerminatingDistinct<R> as(Class<R> resultType) {
+
+				Assert.notNull(resultType, "ResultType must not be null!");
+
+				return new DistinctOperationSupport<>((ReactiveFindSupport) delegate.as(resultType), field);
+			}
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.DistinctWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
+			 */
+			@Override
+			@SuppressWarnings("unchecked")
+			public TerminatingDistinct<T> matching(Query query) {
+
+				Assert.notNull(query, "Query must not be null!");
+
+				return new DistinctOperationSupport<>((ReactiveFindSupport<T>) delegate.matching(query), field);
+			}
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.springframework.data.mongodb.core..ReactiveFindOperation.TerminatingDistinct#all()
+			 */
+			@Override
+			public Flux<T> all() {
+				return delegate.doFindDistinct(field);
+			}
+		}
 	}
 }

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

@@ -19,7 +19,8 @@ package org.springframework.data.mongodb.core;
  * Stripped down interface providing access to a fluent API that specifies a basic set of reactive MongoDB operations.
  *
  * @author Mark Paluch
+ * @author Christoph Strobl
  * @since 2.0
  */
 public interface ReactiveFluentMongoOperations extends ReactiveFindOperation, ReactiveInsertOperation,
-		ReactiveUpdateOperation, ReactiveRemoveOperation, ReactiveAggregationOperation {}
+		ReactiveUpdateOperation, ReactiveRemoveOperation, ReactiveAggregationOperation, ReactiveMapReduceOperation {}

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

@@ -96,7 +96,7 @@ class ReactiveInsertOperationSupport implements ReactiveInsertOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 	}
 }

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

@@ -0,0 +1,199 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import reactor.core.publisher.Flux;
+
+import org.springframework.data.mongodb.core.ExecutableFindOperation.ExecutableFind;
+import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
+import org.springframework.data.mongodb.core.query.Query;
+
+/**
+ * {@link ReactiveMapReduceOperation} allows creation and execution of MongoDB mapReduce operations in a fluent API
+ * style. The starting {@literal domainType} is used for mapping an optional {@link Query} provided via {@code matching}
+ * into the MongoDB specific representation. By default, the originating {@literal domainType} is also used for mapping
+ * back the results from the {@link org.bson.Document}. However, it is possible to define an different
+ * {@literal returnType} via {@code as} to mapping the result.<br />
+ * The collection to operate on is by default derived from the initial {@literal domainType} and can be defined there
+ * via {@link org.springframework.data.mongodb.core.mapping.Document}. Using {@code inCollection} allows to override the
+ * collection name for the execution.
+ * 
+ * <pre>
+ *     <code>
+ *         mapReduce(Human.class)
+ *             .map("function() { emit(this.id, this.firstname) }")
+ *             .reduce("function(id, name) { return sum(id, name); }")
+ *             .inCollection("star-wars")
+ *             .as(Jedi.class)
+ *             .matching(query(where("lastname").is("skywalker")))
+ *             .all();
+ *     </code>
+ * </pre>
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+public interface ReactiveMapReduceOperation {
+
+	/**
+	 * Start creating a mapReduce operation for the given {@literal domainType}.
+	 *
+	 * @param domainType must not be {@literal null}.
+	 * @return new instance of {@link ExecutableFind}.
+	 * @throws IllegalArgumentException if domainType is {@literal null}.
+	 */
+	<T> MapReduceWithMapFunction<T> mapReduce(Class<T> domainType);
+
+	/**
+	 * Trigger mapReduce execution by calling one of the terminating methods.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface TerminatingMapReduce<T> {
+
+		/**
+		 * Get the {@link Flux} emitting mapReduce results.
+		 *
+		 * @return a {@link Flux} emitting the already mapped operation results.
+		 */
+		Flux<T> all();
+	}
+
+	/**
+	 * Provide the Javascript {@code function()} used to map matching documents.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithMapFunction<T> {
+
+		/**
+		 * Set the Javascript map {@code function()}.
+		 *
+		 * @param mapFunction must not be {@literal null} nor empty.
+		 * @return new instance of {@link MapReduceWithReduceFunction}.
+		 * @throws IllegalArgumentException if {@literal mapFunction} is {@literal null} or empty.
+		 */
+		MapReduceWithReduceFunction<T> map(String mapFunction);
+
+	}
+
+	/**
+	 * Provide the Javascript {@code function()} used to reduce matching documents.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithReduceFunction<T> {
+
+		/**
+		 * Set the Javascript map {@code function()}.
+		 *
+		 * @param reduceFunction must not be {@literal null} nor empty.
+		 * @return new instance of {@link ReactiveMapReduce}.
+		 * @throws IllegalArgumentException if {@literal reduceFunction} is {@literal null} or empty.
+		 */
+		ReactiveMapReduce<T> reduce(String reduceFunction);
+
+	}
+
+	/**
+	 * Collection override (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithCollection<T> extends MapReduceWithQuery<T> {
+
+		/**
+		 * Explicitly set the name of the collection to perform the mapReduce operation on. <br />
+		 * Skip this step to use the default collection derived from the domain type.
+		 *
+		 * @param collection must not be {@literal null} nor {@literal empty}.
+		 * @return new instance of {@link MapReduceWithProjection}.
+		 * @throws IllegalArgumentException if collection is {@literal null}.
+		 */
+		MapReduceWithProjection<T> inCollection(String collection);
+	}
+
+	/**
+	 * Input document filter query (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithQuery<T> extends TerminatingMapReduce<T> {
+
+		/**
+		 * Set the filter query to be used.
+		 *
+		 * @param query must not be {@literal null}.
+		 * @return new instance of {@link TerminatingMapReduce}.
+		 * @throws IllegalArgumentException if query is {@literal null}.
+		 */
+		TerminatingMapReduce<T> matching(Query query);
+	}
+
+	/**
+	 * Result type override (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithProjection<T> extends MapReduceWithQuery<T> {
+
+		/**
+		 * Define the target type fields should be mapped to. <br />
+		 * Skip this step if you are anyway only interested in the original domain type.
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link TerminatingMapReduce}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> MapReduceWithQuery<R> as(Class<R> resultType);
+	}
+
+	/**
+	 * Additional mapReduce options (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface MapReduceWithOptions<T> {
+
+		/**
+		 * Set additional options to apply to the mapReduce operation.
+		 *
+		 * @param options must not be {@literal null}.
+		 * @return new instance of {@link ReactiveMapReduce}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
+		 */
+		ReactiveMapReduce<T> with(MapReduceOptions options);
+	}
+
+	/**
+	 * {@link ReactiveMapReduce} provides methods for constructing reactive mapReduce operations in a fluent way.
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface ReactiveMapReduce<T> extends MapReduceWithMapFunction<T>, MapReduceWithReduceFunction<T>,
+			MapReduceWithCollection<T>, MapReduceWithProjection<T>, MapReduceWithOptions<T> {
+
+	}
+}

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

@@ -0,0 +1,177 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+import reactor.core.publisher.Flux;
+
+import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Implementation of {@link ReactiveMapReduceOperation}.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ */
+@RequiredArgsConstructor
+class ReactiveMapReduceOperationSupport implements ReactiveMapReduceOperation {
+
+	private static final Query ALL_QUERY = new Query();
+
+	private final @NonNull ReactiveMongoTemplate template;
+
+	/*
+	 * (non-Javascript)
+	 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation#mapReduce(java.lang.Class)
+	 */
+	@Override
+	public <T> ReactiveMapReduceSupport<T> mapReduce(Class<T> domainType) {
+
+		Assert.notNull(domainType, "DomainType must not be null!");
+
+		return new ReactiveMapReduceSupport<>(template, domainType, domainType, null, ALL_QUERY, null, null, null);
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	static class ReactiveMapReduceSupport<T>
+			implements ReactiveMapReduce<T>, MapReduceWithOptions<T>, MapReduceWithCollection<T>, MapReduceWithProjection<T>,
+			MapReduceWithQuery<T>, MapReduceWithReduceFunction<T>, MapReduceWithMapFunction<T> {
+
+		private final ReactiveMongoTemplate template;
+		private final Class<?> domainType;
+		private final Class<T> returnType;
+		private final @Nullable String collection;
+		private final Query query;
+		private final @Nullable String mapFunction;
+		private final @Nullable String reduceFunction;
+		private final @Nullable MapReduceOptions options;
+
+		ReactiveMapReduceSupport(ReactiveMongoTemplate template, Class<?> domainType, Class<T> returnType,
+				@Nullable String collection, Query query, @Nullable String mapFunction, @Nullable String reduceFunction,
+				@Nullable MapReduceOptions options) {
+
+			this.template = template;
+			this.domainType = domainType;
+			this.returnType = returnType;
+			this.collection = collection;
+			this.query = query;
+			this.mapFunction = mapFunction;
+			this.reduceFunction = reduceFunction;
+			this.options = options;
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ExecutableMapReduceOperation.TerminatingMapReduce#all()
+		 */
+		@Override
+		public Flux<T> all() {
+
+			return template.mapReduce(query, domainType, getCollectionName(), returnType, mapFunction, reduceFunction,
+					options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithCollection#inCollection(java.lang.String)
+		 */
+		@Override
+		public MapReduceWithProjection<T> inCollection(String collection) {
+
+			Assert.hasText(collection, "Collection name must not be null nor empty!");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithQuery#query(org.springframework.data.mongodb.core.query.Query)
+		 */
+		@Override
+		public TerminatingMapReduce<T> matching(Query query) {
+
+			Assert.notNull(query, "Query must not be null!");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithProjection#as(java.lang.Class)
+		 */
+		@Override
+		public <R> MapReduceWithQuery<R> as(Class<R> resultType) {
+
+			Assert.notNull(resultType, "ResultType must not be null!");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, resultType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithOptions#with(org.springframework.data.mongodb.core.mapreduce.MapReduceOptions)
+		 */
+		@Override
+		public ReactiveMapReduce<T> with(MapReduceOptions options) {
+
+			Assert.notNull(options, "Options must not be null! Please consider empty MapReduceOptions#options() instead.");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithMapFunction#map(java.lang.String)
+		 */
+		@Override
+		public MapReduceWithReduceFunction<T> map(String mapFunction) {
+
+			Assert.hasText(mapFunction, "MapFunction name must not be null nor empty!");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		/*
+		 * (non-Javascript)
+		 * @see in org.springframework.data.mongodb.core.ReactiveMapReduceOperation.MapReduceWithReduceFunction#reduce(java.lang.String)
+		 */
+		@Override
+		public ReactiveMapReduce<T> reduce(String reduceFunction) {
+
+			Assert.hasText(reduceFunction, "ReduceFunction name must not be null nor empty!");
+
+			return new ReactiveMapReduceSupport<>(template, domainType, returnType, collection, query, mapFunction,
+					reduceFunction, options);
+		}
+
+		private String getCollectionName() {
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
+		}
+	}
+}

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

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import org.reactivestreams.Publisher;
+import org.springframework.util.Assert;
+import reactor.core.publisher.Mono;
+import reactor.util.context.Context;
+
+import com.mongodb.reactivestreams.client.ClientSession;
+
+/**
+ * {@link ReactiveMongoContext} utilizes and enriches the Reactor {@link Context} with information potentially required
+ * for e.g. {@link ClientSession} handling and transactions.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ * @see Mono#subscriberContext()
+ * @see Context
+ */
+public class ReactiveMongoContext {
+
+	private static final Class<?> SESSION_KEY = ClientSession.class;
+
+	/**
+	 * Gets the {@code Mono<ClientSession>} from Reactor {@link reactor.util.context.Context}. The resulting {@link Mono}
+	 * emits the {@link ClientSession} if a session is associated with the current {@link reactor.util.context.Context
+	 * subscriber context}. If the context does not contain a session, the resulting {@link Mono} terminates empty (i.e.
+	 * without emitting a value).
+	 *
+	 * @return the {@link Mono} emitting the client session if present; otherwise the {@link Mono} terminates empty.
+	 */
+	public static Mono<ClientSession> getSession() {
+
+		return Mono.subscriberContext().filter(ctx -> ctx.hasKey(SESSION_KEY))
+				.flatMap(ctx -> ctx.<Mono<ClientSession>> get(SESSION_KEY));
+	}
+
+	/**
+	 * Sets the {@link ClientSession} into the Reactor {@link reactor.util.context.Context}.
+	 *
+	 * @param context must not be {@literal null}.
+	 * @param session must not be {@literal null}.
+	 * @return a new {@link Context}.
+	 * @see Context#put(Object, Object)
+	 */
+	public static Context setSession(Context context, Publisher<ClientSession> session) {
+
+		Assert.notNull(context, "Context must not be null!");
+		Assert.notNull(session, "Session publisher must not be null!");
+
+		return context.put(SESSION_KEY, Mono.from(session));
+	}
+}

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

@@ -19,27 +19,35 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 import java.util.Collection;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
 
 import org.bson.Document;
 import org.reactivestreams.Publisher;
 import org.reactivestreams.Subscription;
 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.TypedAggregation;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.core.index.ReactiveIndexOperations;
+import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
 import org.springframework.data.mongodb.core.query.BasicQuery;
 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.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
+import com.mongodb.ClientSessionOptions;
 import com.mongodb.ReadPreference;
 import com.mongodb.client.result.DeleteResult;
 import com.mongodb.client.result.UpdateResult;
+import com.mongodb.reactivestreams.client.ClientSession;
 import com.mongodb.reactivestreams.client.MongoCollection;
 
 /**
@@ -48,13 +56,17 @@ import com.mongodb.reactivestreams.client.MongoCollection;
  * Implemented by {@link ReactiveMongoTemplate}. 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). Command execution using
  * {@link ReactiveMongoOperations} is deferred until subscriber subscribes to the {@link Publisher}.
+ * <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>.
  *
  * @author Mark Paluch
  * @author Christoph Strobl
  * @since 2.0
  * @see Flux
  * @see Mono
- * @see <a href="http://projectreactor.io/docs/">Project Reactor</a>
+ * @see <a href="https://projectreactor.io/docs/">Project Reactor</a>
  */
 public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
@@ -140,6 +152,92 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 */
 	<T> Flux<T> execute(String collectionName, ReactiveCollectionCallback<T> action);
 
+	/**
+	 * 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 />
+	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle. Use
+	 * {@link ReactiveSessionScoped#execute(ReactiveSessionCallback, Consumer)} to provide a hook for processing the
+	 * {@link ClientSession} when done.
+	 *
+	 * @param sessionProvider must not be {@literal null}.
+	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 * @since 2.1
+	 */
+	default ReactiveSessionScoped withSession(Supplier<ClientSession> sessionProvider) {
+
+		Assert.notNull(sessionProvider, "SessionProvider must not be null!");
+
+		return withSession(Mono.fromSupplier(sessionProvider));
+	}
+
+	/**
+	 * Obtain a {@link ClientSession session} bound instance of {@link SessionScoped} binding a new {@link ClientSession}
+	 * with given {@literal sessionOptions} to each and every command issued against MongoDB.
+	 * <p />
+	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle. Use
+	 * {@link ReactiveSessionScoped#execute(ReactiveSessionCallback, Consumer)} to provide a hook for processing the
+	 * {@link ClientSession} when done.
+	 *
+	 * @param sessionOptions must not be {@literal null}.
+	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 * @since 2.1
+	 */
+	ReactiveSessionScoped withSession(ClientSessionOptions sessionOptions);
+
+	/**
+	 * Obtain a {@link ClientSession session} bound instance of {@link ReactiveSessionScoped} binding the
+	 * {@link ClientSession} provided by the given {@link Publisher} to each and every command issued against MongoDB.
+	 * <p />
+	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle. Use
+	 * {@link ReactiveSessionScoped#execute(ReactiveSessionCallback, Consumer)} to provide a hook for processing the
+	 * {@link ClientSession} when done.
+	 *
+	 * @param sessionProvider must not be {@literal null}.
+	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 * @since 2.1
+	 */
+	ReactiveSessionScoped withSession(Publisher<ClientSession> sessionProvider);
+
+	/**
+	 * Obtain a {@link ClientSession} bound instance of {@link ReactiveMongoOperations}.
+	 * <p />
+	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle.
+	 *
+	 * @param session must not be {@literal null}.
+	 * @return {@link ClientSession} bound instance of {@link ReactiveMongoOperations}.
+	 * @since 2.1
+	 */
+	ReactiveMongoOperations withSession(ClientSession session);
+
+	/**
+	 * Initiate a new {@link ClientSession} and obtain a {@link ClientSession session} bound instance of
+	 * {@link ReactiveSessionScoped}. Starts the transaction and adds the {@link ClientSession} to each and every command
+	 * issued against MongoDB.
+	 * <p/>
+	 * Each {@link ReactiveSessionScoped#execute(ReactiveSessionCallback) execution} initiates a new managed transaction
+	 * that is {@link ClientSession#commitTransaction() committed} on success. Transactions are
+	 * {@link ClientSession#abortTransaction() rolled back} upon errors.
+	 *
+	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 */
+	ReactiveSessionScoped inTransaction();
+
+	/**
+	 * Obtain a {@link ClientSession session} bound instance of {@link ReactiveSessionScoped}, start the transaction and
+	 * bind the {@link ClientSession} provided by the given {@link Publisher} to each and every command issued against
+	 * MongoDB.
+	 * <p/>
+	 * Each {@link ReactiveSessionScoped#execute(ReactiveSessionCallback) execution} initiates a new managed transaction
+	 * that is {@link ClientSession#commitTransaction() committed} on success. Transactions are
+	 * {@link ClientSession#abortTransaction() rolled back} upon errors.
+	 *
+	 * @param sessionProvider must not be {@literal null}.
+	 * @return new instance of {@link ReactiveSessionScoped}. Never {@literal null}.
+	 * @since 2.1
+	 */
+	ReactiveSessionScoped inTransaction(Publisher<ClientSession> sessionProvider);
+
 	/**
 	 * Create an uncapped collection with a name based on the provided entity class.
 	 *
@@ -183,12 +281,15 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	Flux<String> getCollectionNames();
 
 	/**
-	 * Get a collection by name, creating it if it doesn't exist.
+	 * Get a {@link MongoCollection} by name. The returned collection may not exists yet (except in local memory) and is
+	 * created on first interaction with the server. Collections can be explicitly created via
+	 * {@link #createCollection(Class)}. Please make sure to check if the collection {@link #collectionExists(Class)
+	 * exists} first.
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection.
-	 * @return an existing collection or a newly created one.
+	 * @return an existing collection or one created on first server interaction.
 	 */
 	MongoCollection<Document> getCollection(String collectionName);
 
@@ -377,6 +478,65 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 */
 	<T> Mono<T> findById(Object id, Class<T> entityClass, String collectionName);
 
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link Flux}.
+	 *
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param entityClass the domain type used for determining the actual {@link MongoCollection}. Must not be
+	 *          {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	default <T> Flux<T> findDistinct(String field, Class<?> entityClass, Class<T> resultClass) {
+		return findDistinct(new Query(), field, entityClass, resultClass);
+	}
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link Flux}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param entityClass the domain type used for determining the actual {@link MongoCollection} and mapping the
+	 *          {@link Query} to the domain type fields. Must not be {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> Flux<T> findDistinct(Query query, String field, Class<?> entityClass, Class<T> resultClass);
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link Flux}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param collectionName the explicit name of the actual {@link MongoCollection}. Must not be {@literal null}.
+	 * @param entityClass the domain type used for mapping the {@link Query} to the domain type fields.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> Flux<T> findDistinct(Query query, String field, String collectionName, Class<?> entityClass,
+			Class<T> resultClass);
+
+	/**
+	 * Finds the distinct values for a specified {@literal field} across a single {@link MongoCollection} or view and
+	 * returns the results in a {@link Flux}.
+	 *
+	 * @param query filter {@link Query} to restrict search. Must not be {@literal null}.
+	 * @param field the name of the field to inspect for distinct values. Must not be {@literal null}.
+	 * @param collection the explicit name of the actual {@link MongoCollection}. Must not be {@literal null}.
+	 * @param resultClass the result type. Must not be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 2.1
+	 */
+	default <T> Flux<T> findDistinct(Query query, String field, String collection, Class<T> resultClass) {
+		return findDistinct(query, field, collection, Object.class, resultClass);
+	}
+
 	/**
 	 * Execute an aggregation operation.
 	 * <p>
@@ -536,6 +696,160 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	<T> Mono<T> findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
 			String collectionName);
 
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement}
+	 * document. <br />
+	 * Options are defaulted to {@link FindAndReplaceOptions#empty()}. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found.
+	 * @since 2.1
+	 */
+	default <T> Mono<T> findAndReplace(Query query, T replacement) {
+		return findAndReplace(query, replacement, FindAndReplaceOptions.empty());
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement}
+	 * document. <br />
+	 * Options are defaulted to {@link FindAndReplaceOptions#empty()}. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param collectionName the collection to query. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found.
+	 * @since 2.1
+	 */
+	default <T> Mono<T> findAndReplace(Query query, T replacement, String collectionName) {
+		return findAndReplace(query, replacement, FindAndReplaceOptions.empty(), collectionName);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	default <T> Mono<T> findAndReplace(Query query, T replacement, FindAndReplaceOptions options) {
+		return findAndReplace(query, replacement, options, getCollectionName(ClassUtils.getUserClass(replacement)));
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	default <T> Mono<T> findAndReplace(Query query, T replacement, FindAndReplaceOptions options, String collectionName) {
+
+		Assert.notNull(replacement, "Replacement must not be null!");
+		return findAndReplace(query, replacement, options, (Class<T>) ClassUtils.getUserClass(replacement), collectionName);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType 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 {@link Mono#empty()}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	default <T> Mono<T> findAndReplace(Query query, T replacement, FindAndReplaceOptions options, Class<T> entityType,
+			String collectionName) {
+
+		return findAndReplace(query, replacement, options, entityType, collectionName, entityType);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType the type used for mapping the {@link Query} to domain type fields and deriving the collection
+	 *          from. Must not be {@literal null}.
+	 * @param resultType the parametrized type projection return type. Must not be {@literal null}, use the domain type of
+	 *          {@code Object.class} instead.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	default <S, T> Mono<T> findAndReplace(Query query, S replacement, FindAndReplaceOptions options, Class<S> entityType,
+			Class<T> resultType) {
+
+		return findAndReplace(query, replacement, options, entityType,
+				getCollectionName(ClassUtils.getUserClass(entityType)), resultType);
+	}
+
+	/**
+	 * Triggers
+	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * to replace a single document matching {@link Criteria} of given {@link Query} with the {@code replacement} document
+	 * taking {@link FindAndReplaceOptions} into account. <br />
+	 * <strong>NOTE:</strong> The replacement entity must not hold an {@literal id}.
+	 *
+	 * @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 replacement the replacement document. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityType the type used for mapping the {@link Query} to domain type fields and deriving the collection
+	 *          from. Must not be {@literal null}.
+	 * @param collectionName the collection to query. Must not be {@literal null}.
+	 * @param resultType resultType the parametrized type projection return type. Must not be {@literal null}, use the
+	 *          domain type of {@code Object.class} instead.
+	 * @return the converted object that was updated or {@link Mono#empty()}, if not found. Depending on the value of
+	 *         {@link FindAndReplaceOptions#isReturnNew()} this will either be the object as it was before the update or
+	 *         as it is after the update.
+	 * @since 2.1
+	 */
+	<S, T> Mono<T> findAndReplace(Query query, S replacement, FindAndReplaceOptions options, Class<S> entityType,
+			String collectionName, Class<T> resultType);
+
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity type to a single instance of an object of the
 	 * specified type. The first document that matches the query is returned and also removed from the collection in the
@@ -613,14 +927,14 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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="http://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.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
-	 * @return the saved object.
+	 * @return the inserted object.
 	 */
 	<T> Mono<T> insert(T objectToSave);
 
@@ -634,7 +948,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
-	 * @return the saved object.
+	 * @return the inserted object.
 	 */
 	<T> Mono<T> insert(T objectToSave, String collectionName);
 
@@ -643,7 +957,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param batchToSave the batch of objects to save. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
-	 * @return the saved objects.
+	 * @return the inserted objects .
 	 */
 	<T> Flux<T> insert(Collection<? extends T> batchToSave, Class<?> entityClass);
 
@@ -652,7 +966,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param batchToSave the list of objects to save. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
-	 * @return the saved objects.
+	 * @return the inserted objects.
 	 */
 	<T> Flux<T> insert(Collection<? extends T> batchToSave, String collectionName);
 
@@ -673,14 +987,14 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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="http://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.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
-	 * @return the saved object.
+	 * @return the inserted objects.
 	 */
 	<T> Mono<T> insert(Mono<? extends T> objectToSave);
 
@@ -689,7 +1003,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param batchToSave the publisher which provides objects to save. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
-	 * @return the saved objects.
+	 * @return the inserted objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, Class<?> entityClass);
 
@@ -698,7 +1012,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param batchToSave the publisher which provides objects to save. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
-	 * @return the saved objects.
+	 * @return the inserted objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, String collectionName);
 
@@ -707,7 +1021,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * class.
 	 *
 	 * @param objectsToSave the publisher which provides objects to save. Must not be {@literal null}.
-	 * @return the saved objects.
+	 * @return the inserted objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> objectsToSave);
 
@@ -721,8 +1035,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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="http://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.
@@ -739,8 +1053,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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
-	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's
-	 * Type Conversion"</a> for more details.
+	 * 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}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
@@ -758,8 +1072,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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="http://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.
@@ -776,8 +1090,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * If you 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
-	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's
-	 * Type Conversion"</a> for more details.
+	 * 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}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
@@ -1049,6 +1363,115 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 */
 	<T> Flux<T> tail(Query query, Class<T> entityClass, String collectionName);
 
+	/**
+	 * Subscribe to a MongoDB <a href="https://docs.mongodb.com/manual/changeStreams/">Change Stream</a> for all events in
+	 * the configured default database via the reactive infrastructure. Use the optional provided {@link Aggregation} to
+	 * filter events. The stream will not be completed unless the {@link org.reactivestreams.Subscription} is
+	 * {@link Subscription#cancel() canceled}.
+	 * <p />
+	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
+	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
+	 * <p />
+	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
+	 * for resuming change streams.
+	 *
+	 * @param options must not be {@literal null}. Use {@link ChangeStreamOptions#empty()}.
+	 * @param targetType the result type to use.
+	 * @param <T>
+	 * @return the {@link Flux} emitting {@link ChangeStreamEvent events} as they arrive.
+	 * @since 2.1
+	 * @see ReactiveMongoDatabaseFactory#getMongoDatabase()
+	 * @see ChangeStreamOptions#getFilter()
+	 */
+	default <T> Flux<ChangeStreamEvent<T>> changeStream(ChangeStreamOptions options, Class<T> targetType) {
+		return changeStream(null, options, targetType);
+	}
+
+	/**
+	 * Subscribe to a MongoDB <a href="https://docs.mongodb.com/manual/changeStreams/">Change Stream</a> for all events in
+	 * the given collection via the reactive infrastructure. Use the optional provided {@link Aggregation} to filter
+	 * events. The stream will not be completed unless the {@link org.reactivestreams.Subscription} is
+	 * {@link Subscription#cancel() canceled}.
+	 * <p />
+	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
+	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
+	 * <p />
+	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
+	 * for resuming change streams.
+	 *
+	 * @param collectionName the collection to watch. Can be {@literal null} to watch all collections.
+	 * @param options must not be {@literal null}. Use {@link ChangeStreamOptions#empty()}.
+	 * @param targetType the result type to use.
+	 * @param <T>
+	 * @return the {@link Flux} emitting {@link ChangeStreamEvent events} as they arrive.
+	 * @since 2.1
+	 * @see ChangeStreamOptions#getFilter()
+	 */
+	default <T> Flux<ChangeStreamEvent<T>> changeStream(@Nullable String collectionName, ChangeStreamOptions options,
+			Class<T> targetType) {
+
+		return changeStream(null, collectionName, options, targetType);
+	}
+
+	/**
+	 * Subscribe to a MongoDB <a href="https://docs.mongodb.com/manual/changeStreams/">Change Stream</a> via the reactive
+	 * infrastructure. Use the optional provided {@link Aggregation} to filter events. The stream will not be completed
+	 * unless the {@link org.reactivestreams.Subscription} is {@link Subscription#cancel() canceled}.
+	 * <p />
+	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
+	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
+	 * <p />
+	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
+	 * for resuming change streams.
+	 *
+	 * @param database the database to watch. Can be {@literal null}, uses configured default if so.
+	 * @param collectionName the collection to watch. Can be {@literal null}, watches all collections if so.
+	 * @param options must not be {@literal null}. Use {@link ChangeStreamOptions#empty()}.
+	 * @param targetType the result type to use.
+	 * @param <T>
+	 * @return the {@link Flux} emitting {@link ChangeStreamEvent events} as they arrive.
+	 * @since 2.1
+	 * @see ChangeStreamOptions#getFilter()
+	 */
+	<T> Flux<ChangeStreamEvent<T>> changeStream(@Nullable String database, @Nullable String collectionName,
+			ChangeStreamOptions options, Class<T> targetType);
+
+	/**
+	 * Execute a map-reduce operation. Use {@link MapReduceOptions} to optionally specify an output collection and other
+	 * args.
+	 *
+	 * @param filterQuery the selection criteria for the documents going input to the map function. Must not be
+	 *          {@literal null}.
+	 * @param domainType source type used to determine the input collection name and map the filter {@link Query} against.
+	 *          Must not be {@literal null}.
+	 * @param resultType the mapping target of the operations result documents. Must not be {@literal null}.
+	 * @param mapFunction the JavaScript map function. Must not be {@literal null}.
+	 * @param reduceFunction the JavaScript reduce function. Must not be {@literal null}.
+	 * @param options additional options like output collection. Must not be {@literal null}.
+	 * @return a {@link Flux} emitting the result document sequence. Never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> Flux<T> mapReduce(Query filterQuery, Class<?> domainType, Class<T> resultType, String mapFunction,
+			String reduceFunction, MapReduceOptions options);
+
+	/**
+	 * Execute a map-reduce operation. Use {@link MapReduceOptions} to optionally specify an output collection and other
+	 * args.
+	 *
+	 * @param filterQuery the selection criteria for the documents going input to the map function. Must not be
+	 *          {@literal null}.
+	 * @param domainType source type used to map the filter {@link Query} against. Must not be {@literal null}.
+	 * @param inputCollectionName the input collection.
+	 * @param resultType the mapping target of the operations result documents. Must not be {@literal null}.
+	 * @param mapFunction the JavaScript map function. Must not be {@literal null}.
+	 * @param reduceFunction the JavaScript reduce function. Must not be {@literal null}.
+	 * @param options additional options like output collection. Must not be {@literal null}.
+	 * @return a {@link Flux} emitting the result document sequence. Never {@literal null}.
+	 * @since 2.1
+	 */
+	<T> Flux<T> mapReduce(Query filterQuery, Class<?> domainType, String inputCollectionName, Class<T> resultType,
+			String mapFunction, String reduceFunction, MapReduceOptions options);
+
 	/**
 	 * Returns the underlying {@link MongoConverter}.
 	 *
@@ -1056,4 +1479,13 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 */
 	MongoConverter getConverter();
 
+	/**
+	 * The collection name used for the specified class by this template.
+	 *
+	 * @param entityClass must not be {@literal null}.
+	 * @return
+	 * @since 2.1
+	 */
+	String getCollectionName(Class<?> entityClass);
+
 }

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

@@ -112,7 +112,7 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 		}
 
 		private String getCollectionName() {
-			return StringUtils.hasText(collection) ? collection : template.determineCollectionName(domainType);
+			return StringUtils.hasText(collection) ? collection : template.getCollectionName(domainType);
 		}
 
 	}

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

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import org.reactivestreams.Publisher;
+import org.springframework.data.mongodb.core.query.Query;
+
+/**
+ * Callback interface for executing operations within a {@link com.mongodb.reactivestreams.client.ClientSession} using
+ * reactive infrastructure.
+ *
+ * @author Christoph Strobl
+ * @since 2.1
+ * @see com.mongodb.reactivestreams.client.ClientSession
+ */
+@FunctionalInterface
+public interface ReactiveSessionCallback<T> {
+
+	/**
+	 * Execute operations against a MongoDB instance via session bound {@link ReactiveMongoOperations}. The session is
+	 * inferred directly into the operation so that no further interaction is necessary.
+	 * <p />
+	 * Please note that only Spring Data-specific abstractions like {@link ReactiveMongoOperations#find(Query, Class)} and
+	 * others are enhanced with the {@link com.mongodb.session.ClientSession}. When obtaining plain MongoDB gateway
+	 * objects like {@link com.mongodb.reactivestreams.client.MongoCollection} or
+	 * {@link com.mongodb.reactivestreams.client.MongoDatabase} via eg.
+	 * {@link ReactiveMongoOperations#getCollection(String)} we leave responsibility for
+	 * {@link com.mongodb.session.ClientSession} again up to the caller.
+	 *
+	 * @param operations will never be {@literal null}.
+	 * @return never {@literal null}.
+	 */
+	Publisher<T> doInSession(ReactiveMongoOperations operations);
+}

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

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2018-2019 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.core;
+
+import reactor.core.publisher.Flux;
+
+import java.util.function.Consumer;
+
+import com.mongodb.reactivestreams.client.ClientSession;
+
+/**
+ * Gateway interface to execute {@link ClientSession} bound operations against MongoDB via a
+ * {@link ReactiveSessionCallback}.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ * @since 2.1
+ */
+public interface ReactiveSessionScoped {
+
+	/**
+	 * Executes the given {@link ReactiveSessionCallback} within the {@link com.mongodb.session.ClientSession}.
+	 * <p/>
+	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
+	 * closed} when done.
+	 *
+	 * @param action callback object that specifies the MongoDB action the callback action. Must not be {@literal null}.
+	 * @param <T> return type.
+	 * @return a result object returned by the action, can be {@link Flux#empty()}.
+	 */
+	default <T> Flux<T> execute(ReactiveSessionCallback<T> action) {
+		return execute(action, (session) -> {});
+	}
+
+	/**
+	 * Executes the given {@link ReactiveSessionCallback} within the {@link com.mongodb.session.ClientSession}.
+	 * <p/>
+	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
+	 * closed} when done.
+	 *
+	 * @param action callback object that specifies the MongoDB action the callback action. Must not be {@literal null}.
+	 * @param doFinally callback object that accepts {@link ClientSession} after invoking {@link ReactiveSessionCallback}.
+	 *          This {@link Consumer} is guaranteed to be notified in any case (successful and exceptional outcome of
+	 *          {@link ReactiveSessionCallback}).
+	 * @param <T> return type.
+	 * @return a result object returned by the action, can be {@link Flux#empty()}.
+	 */
+	<T> Flux<T> execute(ReactiveSessionCallback<T> action, Consumer<ClientSession> doFinally);
+}

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

@@ -18,12 +18,13 @@ package org.springframework.data.mongodb.core;
 import reactor.core.publisher.Mono;
 
 import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.data.mongodb.core.query.Update;
 
 import com.mongodb.client.result.UpdateResult;
 
 /**
- * {@link ReactiveUpdateOperation} allows creation and execution of reactive MongoDB update / findAndModify operations
- * in a fluent API style. <br />
+ * {@link ReactiveUpdateOperation} allows creation and execution of reactive MongoDB update / findAndModify /
+ * findAndReplace operations in a fluent API style. <br />
  * The starting {@literal domainType} is used for mapping the {@link Query} provided via {@code matching}, as well as
  * the {@link org.springframework.data.mongodb.core.query.Update} via {@code apply} into the MongoDB specific
  * representations. The collection to operate on is by default derived from the initial {@literal domainType} and can be
@@ -68,6 +69,22 @@ public interface ReactiveUpdateOperation {
 		Mono<T> findAndModify();
 	}
 
+	/**
+	 * Compose findAndReplace execution by calling one of the terminating methods.
+	 *
+	 * @author Mark Paluch
+	 * @since 2.1
+	 */
+	interface TerminatingFindAndReplace<T> {
+
+		/**
+		 * Find, replace and return the first matching document.
+		 *
+		 * @return {@link Mono#empty()} if nothing found. Never {@literal null}.
+		 */
+		Mono<T> findAndReplace();
+	}
+
 	/**
 	 * Compose update execution by calling one of the terminating methods.
 	 */
@@ -108,6 +125,16 @@ public interface ReactiveUpdateOperation {
 		 * @throws IllegalArgumentException if update is {@literal null}.
 		 */
 		TerminatingUpdate<T> apply(org.springframework.data.mongodb.core.query.Update update);
+
+		/**
+		 * Specify {@code replacement} object.
+		 *
+		 * @param replacement must not be {@literal null}.
+		 * @return new instance of {@link FindAndReplaceOptions}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
+		 * @since 2.1
+		 */
+		FindAndReplaceWithProjection<T> replaceWith(T replacement);
 	}
 
 	/**
@@ -157,5 +184,45 @@ public interface ReactiveUpdateOperation {
 		TerminatingFindAndModify<T> withOptions(FindAndModifyOptions options);
 	}
 
+	/**
+	 * Define {@link FindAndReplaceOptions}.
+	 *
+	 * @author Mark Paluch
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface FindAndReplaceWithOptions<T> extends TerminatingFindAndReplace<T> {
+
+		/**
+		 * Explicitly define {@link FindAndReplaceOptions} for the {@link Update}.
+		 *
+		 * @param options must not be {@literal null}.
+		 * @return new instance of {@link FindAndReplaceOptions}.
+		 * @throws IllegalArgumentException if options is {@literal null}.
+		 */
+		FindAndReplaceWithProjection<T> withOptions(FindAndReplaceOptions options);
+	}
+
+	/**
+	 * Result type override (Optional).
+	 *
+	 * @author Christoph Strobl
+	 * @since 2.1
+	 */
+	interface FindAndReplaceWithProjection<T> extends FindAndReplaceWithOptions<T> {
+
+		/**
+		 * Define the target type fields should be mapped to. <br />
+		 * Skip this step if you are anyway only interested in the original domain type.
+		 *
+		 * @param resultType must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return new instance of {@link FindAndReplaceWithProjection}.
+		 * @throws IllegalArgumentException if resultType is {@literal null}.
+		 */
+		<R> FindAndReplaceWithOptions<R> as(Class<R> resultType);
+
+	}
+
 	interface ReactiveUpdate<T> extends UpdateWithCollection<T>, UpdateWithQuery<T>, UpdateWithUpdate<T> {}
 }