Release version 4.0 M1 (2022.0.0).

See #3927

.github/workflows/project.yml

@@ -36,7 +36,7 @@ jobs:
           token: ${{ secrets.GH_ISSUES_TOKEN_SPRING_DATA }}
   Feedback-Provided:
     runs-on: ubuntu-latest
-    if: github.repository_owner == 'spring-projects' && github.event.action == 'created' && contains(join(github.event.issue.labels.*.name, ', '), 'waiting-for-feedback')
+    if: github.repository_owner == 'spring-projects' && github.event_name == 'issue_comment' && github.event.action == 'created' && github.actor != 'spring-projects-issues' && github.event.pull_request == null && github.event.issue.state == 'open' && contains(toJSON(github.event.issue.labels), 'waiting-for-feedback')
     steps:
       - name: Update Project Card
         uses: peter-evans/create-or-update-project-card@v1.1.2

.mvn/wrapper/maven-wrapper.properties

@@ -1 +1,2 @@
-distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.5.4/apache-maven-3.5.4-bin.zip
+#Mon Oct 11 14:30:24 CEST 2021
+distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.3/apache-maven-3.8.3-bin.zip

CI.adoc

@@ -1,6 +1,6 @@
 = 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%2Fmain&subject=Moore%20(main)[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/]
 

CONTRIBUTING.adoc

@@ -1,3 +1,3 @@
 = Spring Data contribution guidelines
 
-You find the contribution guidelines for Spring Data projects https://github.com/spring-projects/spring-data-build/blob/master/CONTRIBUTING.adoc[here].
+You find the contribution guidelines for Spring Data projects https://github.com/spring-projects/spring-data-build/blob/main/CONTRIBUTING.adoc[here].

Jenkinsfile

@@ -3,7 +3,7 @@ pipeline {
 
 	triggers {
 		pollSCM 'H/10 * * * *'
-		upstream(upstreamProjects: "spring-data-commons/master", threshold: hudson.model.Result.SUCCESS)
+		upstream(upstreamProjects: "spring-data-commons/main", threshold: hudson.model.Result.SUCCESS)
 	}
 
 	options {
@@ -14,61 +14,46 @@ pipeline {
 	stages {
 		stage("Docker images") {
 			parallel {
-				stage('Publish JDK 8 + MongoDB 4.0') {
+				stage('Publish JDK 17 + MongoDB 4.4') {
 					when {
-						changeset "ci/openjdk8-mongodb-4.0/**"
+						changeset "ci/openjdk17-mongodb-4.4/**"
 					}
 					agent { label 'data' }
 					options { timeout(time: 30, unit: 'MINUTES') }
 
 					steps {
 						script {
-							def image = docker.build("springci/spring-data-openjdk8-with-mongodb-4.0", "ci/openjdk8-mongodb-4.0/")
+							def image = docker.build("springci/spring-data-openjdk17-with-mongodb-4.4.4", "ci/openjdk17-mongodb-4.4/")
 							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
 								image.push()
 							}
 						}
 					}
 				}
-				stage('Publish JDK 8 + MongoDB 4.2') {
-					when {
-						changeset "ci/openjdk8-mongodb-4.2/**"
-					}
-					agent { label 'data' }
-					options { timeout(time: 30, unit: 'MINUTES') }
+				stage('Publish JDK 17 + MongoDB 5.0') {
+                	when {
+                		changeset "ci/openjdk17-mongodb-5.0/**"
+                	}
+                	agent { label 'data' }
+                	options { timeout(time: 30, unit: 'MINUTES') }
 
-					steps {
-						script {
-							def image = docker.build("springci/spring-data-openjdk8-with-mongodb-4.2.0", "ci/openjdk8-mongodb-4.2/")
-							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-								image.push()
-							}
-						}
-					}
-				}
-				stage('Publish JDK 15 + MongoDB 4.2') {
-					when {
-						changeset "ci/openjdk15-mongodb-4.2/**"
-					}
-					agent { label 'data' }
-					options { timeout(time: 30, unit: 'MINUTES') }
-
-					steps {
-						script {
-							def image = docker.build("springci/spring-data-openjdk15-with-mongodb-4.2.0", "ci/openjdk15-mongodb-4.2/")
-							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-								image.push()
-							}
-						}
-					}
-				}
+                	steps {
+                		script {
+                			def image = docker.build("springci/spring-data-openjdk17-with-mongodb-5.0.3", "ci/openjdk17-mongodb-5.0/")
+                			docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
+                				image.push()
+                			}
+                		}
+                	}
+                }
 			}
 		}
 
-		stage("test: baseline (jdk8)") {
+		stage("test: baseline Mongo 5.0 (jdk17)") {
 			when {
+				beforeAgent(true)
 				anyOf {
-					branch 'master'
+					branch(pattern: "main|(\\d\\.\\d\\.x)", comparator: "REGEXP")
 					not { triggeredBy 'UpstreamCause' }
 				}
 			}
@@ -76,16 +61,19 @@ pipeline {
 				label 'data'
 			}
 			options { timeout(time: 30, unit: 'MINUTES') }
+			environment {
+				ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+			}
 			steps {
 				script {
 					docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-						docker.image('springci/spring-data-openjdk8-with-mongodb-4.2.0:latest').inside('-v $HOME:/tmp/jenkins-home') {
+						docker.image('springci/spring-data-openjdk17-with-mongodb-5.0.3:latest').inside('-v $HOME:/tmp/jenkins-home') {
 							sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
 							sh 'mongod --setParameter transactionLifetimeLimitSeconds=90 --setParameter maxTransactionLockRequestTimeoutMillis=10000 --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 -Duser.name=jenkins -Dsort -U -B'
+							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml clean dependency:list test -Duser.name=jenkins -Dsort -U -B'
 						}
 					}
 				}
@@ -94,69 +82,31 @@ pipeline {
 
 		stage("Test other configurations") {
 			when {
+				beforeAgent(true)
 				allOf {
-					branch 'master'
+					branch(pattern: "main|(\\d\\.\\d\\.x)", comparator: "REGEXP")
 					not { triggeredBy 'UpstreamCause' }
 				}
 			}
 			parallel {
-				stage("test: mongodb 4.0 (jdk8)") {
+				stage("test: baseline MongoDB 4.4 (jdk17)") {
 					agent {
 						label 'data'
 					}
 					options { timeout(time: 30, unit: 'MINUTES') }
+					environment {
+						ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
+					}
 					steps {
 						script {
 							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-								docker.image('springci/spring-data-openjdk8-with-mongodb-4.0:latest').inside('-v $HOME:/tmp/jenkins-home') {
+								docker.image('springci/spring-data-openjdk17-with-mongodb-4.4.4:latest').inside('-v $HOME:/tmp/jenkins-home') {
 									sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
 									sh 'mongod --setParameter transactionLifetimeLimitSeconds=90 --setParameter maxTransactionLockRequestTimeoutMillis=10000 --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 -Duser.name=jenkins -Dsort -U -B'
-								}
-							}
-						}
-					}
-				}
-
-				stage("test: mongodb 4.2 (jdk8)") {
-					agent {
-						label 'data'
-					}
-					options { timeout(time: 30, unit: 'MINUTES') }
-					steps {
-						script {
-							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-								docker.image('springci/spring-data-openjdk8-with-mongodb-4.2.0:latest').inside('-v $HOME:/tmp/jenkins-home') {
-									sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
-									sh 'mongod --setParameter transactionLifetimeLimitSeconds=90 --setParameter maxTransactionLockRequestTimeoutMillis=10000 --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 -Duser.name=jenkins -Dsort -U -B'
-								}
-							}
-						}
-					}
-				}
-
-				stage("test: baseline (jdk15)") {
-					agent {
-						label 'data'
-					}
-					options { timeout(time: 30, unit: 'MINUTES') }
-					steps {
-						script {
-							docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-								docker.image('springci/spring-data-openjdk15-with-mongodb-4.2.0:latest').inside('-v $HOME:/tmp/jenkins-home') {
-									sh 'mkdir -p /tmp/mongodb/db /tmp/mongodb/log'
-									sh 'mongod --setParameter transactionLifetimeLimitSeconds=90 --setParameter maxTransactionLockRequestTimeoutMillis=10000 --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 -Pjava11 clean dependency:list test -Duser.name=jenkins -Dsort -U -B'
+									sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml clean dependency:list test -Duser.name=jenkins -Dsort -U -B'
 								}
 							}
 						}
@@ -167,8 +117,9 @@ pipeline {
 
 		stage('Release to artifactory') {
 			when {
+				beforeAgent(true)
 				anyOf {
-					branch 'master'
+					branch(pattern: "main|(\\d\\.\\d\\.x)", comparator: "REGEXP")
 					not { triggeredBy 'UpstreamCause' }
 				}
 			}
@@ -184,8 +135,8 @@ pipeline {
 			steps {
 				script {
 					docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-						docker.image('adoptopenjdk/openjdk8:latest').inside('-v $HOME:/tmp/jenkins-home') {
-							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,artifactory ' +
+						docker.image('openjdk:17-bullseye').inside('-v $HOME:/tmp/jenkins-home') {
+							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml -Pci,artifactory ' +
 									'-Dartifactory.server=https://repo.spring.io ' +
 									"-Dartifactory.username=${ARTIFACTORY_USR} " +
 									"-Dartifactory.password=${ARTIFACTORY_PSW} " +
@@ -198,35 +149,6 @@ pipeline {
 				}
 			}
 		}
-
-		stage('Publish documentation') {
-			when {
-				branch 'master'
-			}
-			agent {
-				label 'data'
-			}
-			options { timeout(time: 20, unit: 'MINUTES') }
-
-			environment {
-				ARTIFACTORY = credentials('02bd1690-b54f-4c9f-819d-a77cb7a9822c')
-			}
-
-			steps {
-				script {
-					docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-						docker.image('adoptopenjdk/openjdk8:latest').inside('-v $HOME:/tmp/jenkins-home') {
-							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -Pci,distribute ' +
-									'-Dartifactory.server=https://repo.spring.io ' +
-									"-Dartifactory.username=${ARTIFACTORY_USR} " +
-									"-Dartifactory.password=${ARTIFACTORY_PSW} " +
-									"-Dartifactory.distribution-repository=temp-private-local " +
-									'-Dmaven.test.skip=true clean deploy -U -B'
-						}
-					}
-				}
-			}
-		}
 	}
 
 	post {

LICENSE.txt

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   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.

README.adoc

@@ -1,6 +1,6 @@
 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]]
+= Spring Data MongoDB image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-mongodb%2Fmain&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.
 
@@ -8,10 +8,12 @@ The Spring Data MongoDB project aims to provide a familiar and consistent Spring
 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]]
 == Code of Conduct
 
 This project is governed by the https://github.com/spring-projects/.github/blob/e3cc2ff230d8f1dca06535aa6b5a4a23815861d4/CODE_OF_CONDUCT.md[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]]
 == Getting Started
 
 Here is a quick teaser of an application using Spring Data Repositories in Java:
@@ -59,6 +61,7 @@ class ApplicationConfig extends AbstractMongoClientConfiguration {
 }
 ----
 
+[[maven-configuration]]
 === Maven configuration
 
 Add the Maven dependency:
@@ -68,24 +71,25 @@ Add the Maven dependency:
 <dependency>
   <groupId>org.springframework.data</groupId>
   <artifactId>spring-data-mongodb</artifactId>
-  <version>${version}.RELEASE</version>
+  <version>${version}</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.
+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>${version}.BUILD-SNAPSHOT</version>
+  <version>${version}-SNAPSHOT</version>
 </dependency>
 
 <repository>
-  <id>spring-libs-snapshot</id>
+  <id>spring-snapshot</id>
   <name>Spring Snapshot Repository</name>
-  <url>https://repo.spring.io/libs-snapshot</url>
+  <url>https://repo.spring.io/snapshot</url>
 </repository>
 ----
 
@@ -98,7 +102,7 @@ Some of the changes affect the initial setup configuration as well as compile/ru
 
 .Changed XML Namespace Elements and Attributes:
 |===
-Element / Attribute | 2.x | 3.x
+| Element / Attribute | 2.x | 3.x
 
 | `<mongo:mongo-client />`
 | Used to create a `com.mongodb.MongoClient`
@@ -116,7 +120,7 @@ Use `<mongo:client-settings cluster-hosts="..." />` instead
 
 .Removed XML Namespace Elements and Attributes:
 |===
-Element / Attribute | Replacement in 3.x | Comment
+| Element / Attribute | Replacement in 3.x | Comment
 
 | `<mongo:db-factory mongo-ref="..." />`
 | `<mongo:db-factory mongo-client-ref="..." />`
@@ -133,7 +137,7 @@ Element / Attribute | Replacement in 3.x | Comment
 
 .New XML Namespace Elements and Attributes:
 |===
-Element | Comment
+| Element | Comment
 
 | `<mongo:db-factory mongo-client-ref="..." />`
 | Replacement for `<mongo:db-factory mongo-ref="..." />`
@@ -153,7 +157,7 @@ Element | Comment
 
 .Java API changes
 |===
-Type | Comment
+| Type | Comment
 
 | `MongoClientFactoryBean`
 | Creates `com.mongodb.client.MongoClient` instead of `com.mongodb.MongoClient` +
@@ -174,7 +178,7 @@ Uses `MongoClientSettings` instead of `MongoClientOptions`.
 
 .Removed Java API:
 |===
-2.x | Replacement in 3.x | Comment
+| 2.x | Replacement in 3.x | Comment
 
 | `MongoClientOptionsFactoryBean`
 | `MongoClientSettingsFactoryBean`
@@ -226,6 +230,7 @@ static class Config extends AbstractMongoClientConfiguration {
 ----
 ====
 
+[[getting-help]]
 == Getting Help
 
 Having trouble with Spring Data? We’d love to help!
@@ -239,6 +244,7 @@ If you are just starting out with Spring, try one of the https://spring.io/guide
 You can also chat with the community on https://gitter.im/spring-projects/spring-data[Gitter].
 * Report bugs with Spring Data MongoDB at https://github.com/spring-projects/spring-data-mongodb/issues[github.com/spring-projects/spring-data-mongodb/issues].
 
+[[reporting-issues]]
 == Reporting Issues
 
 Spring Data uses Github as issue tracking system to record bugs and feature requests.
@@ -249,10 +255,86 @@ If you want to raise an issue, please follow the recommendations below:
 * Please provide as much information as possible with the issue report, we like to know the version of Spring Data that you are using, the JVM version, Stacktrace, etc.
 * If you need to paste code, or include a stack trace use https://guides.github.com/features/mastering-markdown/[Markdown] code fences +++```+++.
 
+[[guides]]
+== 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]]
+== Examples
+
+* https://github.com/spring-projects/spring-data-examples/[Spring Data Examples] contains example projects that explain specific features in more detail.
+
+[[building-from-source]]
 == 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.
+You do not need to build from source to use Spring Data. Binaries are available in https://repo.spring.io[repo.spring.io]
+and accessible from Maven using the Maven configuration noted <<maven-configuration,above>>.
+
+NOTE: Configuration for Gradle is similar to Maven.
+
+The best way to get started is by creating a Spring Boot project using MongoDB on https://start.spring.io[start.spring.io].
+Follow this https://start.spring.io/#type=maven-project&language=java&platformVersion=2.5.4&packaging=jar&jvmVersion=1.8&groupId=com.example&artifactId=demo&name=demo&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.demo&dependencies=data-mongodb[link]
+to build an imperative application and this https://start.spring.io/#type=maven-project&language=java&platformVersion=2.5.4&packaging=jar&jvmVersion=1.8&groupId=com.example&artifactId=demo&name=demo&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.demo&dependencies=data-mongodb-reactive[link]
+to build a reactive one.
+
+However, if you want to try out the latest and greatest, Spring Data MongoDB can be easily built with the https://github.com/takari/maven-wrapper[Maven wrapper]
+and minimally, JDK 8 (https://www.oracle.com/java/technologies/downloads/[JDK downloads]).
+
+In order to build Spring Data MongoDB, you will need to https://www.mongodb.com/try/download/community[download]
+and https://docs.mongodb.com/manual/installation/[install a MongoDB distribution].
+
+Once you have installed MongoDB, you need to start a MongoDB server. It is convenient to set an environment variable to
+your MongoDB installation directory (e.g. `MONGODB_HOME`).
+
+To run the full test suite, a https://docs.mongodb.com/manual/tutorial/deploy-replica-set/[MongoDB Replica Set]
+is required.
+
+To run the MongoDB server enter the following command from a command-line:
+
+[source,bash]
+----
+$ $MONGODB_HOME/bin/mongod --dbpath $MONGODB_HOME/runtime/data --ipv6 --port 27017 --replSet rs0
+...
+"msg":"Successfully connected to host"
+----
+
+Once the MongoDB server starts up, you should see the message (`msg`), "_Successfully connected to host_".
+
+Notice the `--dbpath` option to the `mongod` command. You can set this to anything you like, but in this case, we set
+the absolute path to a sub-directory (`runtime/data/`) under the MongoDB installation directory (in `$MONGODB_HOME`).
+
+You need to initialize the MongoDB replica set only once on the first time the MongoDB server is started.
+To initialize the replica set, start a mongo client:
+
+[source,bash]
+----
+$ $MONGODB_HOME/bin/mongo
+MongoDB server version: 5.0.0
+...
+----
+
+Then enter the following command:
+
+[source,bash]
+----
+mongo> rs.initiate({ _id: 'rs0', members: [ { _id: 0, host: '127.0.0.1:27017' } ] })
+----
+
+Finally, on UNIX-based system (for example, Linux or Mac OS X) you may need to adjust the `ulimit`.
+In case you need to, you can adjust the `ulimit` with the following command (32768 is just a recommendation):
+
+[source,bash]
+----
+$ ulimit -n 32768
+----
+
+You can use `ulimit -a` again to verify the `ulimit` for "_open files_" was set appropriately.
+
+Now you are ready to build Spring Data MongoDB. Simply enter the following `mvnw` (Maven Wrapper) command:
 
 [source,bash]
 ----
@@ -261,7 +343,8 @@ You also need JDK 1.8.
 
 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._
+_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
 
@@ -274,17 +357,7 @@ Building the documentation builds also the project without running tests.
 
 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]]
 == License
 
 Spring Data MongoDB is Open Source software released under the https://www.apache.org/licenses/LICENSE-2.0.html[Apache 2.0 license].

ci/openjdk11-mongodb-4.2/Dockerfile

@@ -1,15 +0,0 @@
-FROM adoptopenjdk/openjdk11:latest
-
-ENV TZ=Etc/UTC
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN set -eux; \
-	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 ; \
-	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv e162f504a20cdf15827f718d4b7c549a058f8b6b ; \
-	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list; \
-	echo ${TZ} > /etc/timezone;
-
-RUN apt-get update ; \
-	apt-get install -y mongodb-org=4.2.0 mongodb-org-server=4.2.0 mongodb-org-shell=4.2.0 mongodb-org-mongos=4.2.0 mongodb-org-tools=4.2.0 ; \
-	apt-get clean; \
-	rm -rf /var/lib/apt/lists/*;

ci/openjdk15-mongodb-4.2/Dockerfile

@@ -1,15 +0,0 @@
-FROM adoptopenjdk/openjdk15:latest
-
-ENV TZ=Etc/UTC
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN set -eux; \
-	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 ; \
-	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv e162f504a20cdf15827f718d4b7c549a058f8b6b ; \
-	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list; \
-	echo ${TZ} > /etc/timezone;
-
-RUN apt-get update ; \
-	apt-get install -y mongodb-org=4.2.0 mongodb-org-server=4.2.0 mongodb-org-shell=4.2.0 mongodb-org-mongos=4.2.0 mongodb-org-tools=4.2.0 ; \
-	apt-get clean; \
-	rm -rf /var/lib/apt/lists/*;

ci/openjdk17-mongodb-4.4/Dockerfile

@@ -0,0 +1,18 @@
+FROM openjdk:17-bullseye
+
+ENV TZ=Etc/UTC
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN set -eux; \
+	sed -i -e 's/archive.ubuntu.com/mirror.one.com/g' /etc/apt/sources.list; \
+	sed -i -e 's/security.ubuntu.com/mirror.one.com/g' /etc/apt/sources.list; \
+	sed -i -e 's/http/https/g' /etc/apt/sources.list ; \
+	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 ; \
+	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv 656408E390CFB1F5 ; \
+	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.4 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.4.list; \
+	echo ${TZ} > /etc/timezone;
+
+RUN apt-get update ; \
+	apt-get install -y mongodb-org=4.4.4 mongodb-org-server=4.4.4 mongodb-org-shell=4.4.4 mongodb-org-mongos=4.4.4 mongodb-org-tools=4.4.4 ; \
+	apt-get clean; \
+	rm -rf /var/lib/apt/lists/*;

ci/openjdk17-mongodb-5.0/Dockerfile

@@ -0,0 +1,21 @@
+FROM openjdk:17-bullseye
+
+ENV TZ=Etc/UTC
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN set -eux; \
+	sed -i -e 's/archive.ubuntu.com/mirror.one.com/g' /etc/apt/sources.list; \
+	sed -i -e 's/security.ubuntu.com/mirror.one.com/g' /etc/apt/sources.list; \
+	sed -i -e 's/http/https/g' /etc/apt/sources.list ; \
+	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 wget ; \
+	# MongoDB 5.0 release signing key
+	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv B00A0BD1E2C63C11 ; \
+	# Needed when MongoDB creates a 5.0 folder.
+	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/5.0 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-5.0.list; \
+	echo ${TZ} > /etc/timezone;
+
+RUN apt-get update; \
+	apt-get install -y mongodb-org=5.0.3 mongodb-org-server=5.0.3 mongodb-org-shell=5.0.3 mongodb-org-mongos=5.0.3 mongodb-org-tools=5.0.3; \
+	apt-get clean; \
+	rm -rf /var/lib/apt/lists/*;
+

ci/openjdk8-mongodb-4.0/Dockerfile

@@ -1,15 +0,0 @@
-FROM adoptopenjdk/openjdk8:latest
-
-ENV TZ=Etc/UTC
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN RUN set -eux; \
-	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 ; \
-	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4 ; \
-	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; \
-	echo ${TZ} > /etc/timezone;
-
-RUN apt-get update ; \
-	apt-get install -y mongodb-org=4.0.14 mongodb-org-server=4.0.14 mongodb-org-shell=4.0.14 mongodb-org-mongos=4.0.14 mongodb-org-tools=4.0.14 ; \
-	apt-get clean; \
-	rm -rf /var/lib/apt/lists/*;

ci/openjdk8-mongodb-4.2/Dockerfile

@@ -1,15 +0,0 @@
-FROM adoptopenjdk/openjdk8:latest
-
-ENV TZ=Etc/UTC
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN set -eux; \
-	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 ; \
-	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv e162f504a20cdf15827f718d4b7c549a058f8b6b ; \
-	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list; \
-	echo ${TZ} > /etc/timezone;
-
-RUN apt-get update ; \
-	apt-get install -y mongodb-org=4.2.0 mongodb-org-server=4.2.0 mongodb-org-shell=4.2.0 mongodb-org-mongos=4.2.0 mongodb-org-tools=4.2.0 ; \
-	apt-get clean; \
-	rm -rf /var/lib/apt/lists/*;

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>3.2.0-M2</version>
+	<version>4.0.0-M1</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>2.5.0-M2</version>
+		<version>3.0.0-M1</version>
 	</parent>
 
 	<modules>
@@ -24,10 +24,11 @@
 	</modules>
 
 	<properties>
+		<source.level>16</source.level>
 		<project.type>multi</project.type>
 		<dist.id>spring-data-mongodb</dist.id>
-		<springdata.commons>2.5.0-M2</springdata.commons>
-		<mongo>4.1.1</mongo>
+		<springdata.commons>3.0.0-M1</springdata.commons>
+		<mongo>4.4.1</mongo>
 		<mongo.reactivestreams>${mongo}</mongo.reactivestreams>
 		<jmh.version>1.19</jmh.version>
 	</properties>
@@ -141,11 +142,11 @@
 			<id>sonatype-libs-snapshot</id>
 			<url>https://oss.sonatype.org/content/repositories/snapshots</url>
 			<releases>
-        <enabled>false</enabled>
-      </releases>
+				<enabled>false</enabled>
+			</releases>
 			<snapshots>
-        <enabled>true</enabled>
-      </snapshots>
+				<enabled>true</enabled>
+			</snapshots>
 		</repository>
 	</repositories>
 
@@ -158,11 +159,6 @@
 			<id>spring-libs-milestone</id>
 			<url>https://repo.spring.io/libs-milestone</url>
 		</pluginRepository>
-		<pluginRepository>
-			<id>bintray-plugins</id>
-			<name>bintray-plugins</name>
-			<url>https://jcenter.bintray.com</url>
-		</pluginRepository>
 	</pluginRepositories>
 
 </project>

settings.xml

@@ -0,0 +1,29 @@
+<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
+          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
+                      https://maven.apache.org/xsd/settings-1.0.0.xsd">
+
+	<servers>
+		<server>
+			<id>spring-plugins-release</id>
+			<username>${env.ARTIFACTORY_USR}</username>
+			<password>${env.ARTIFACTORY_PSW}</password>
+		</server>
+		<server>
+			<id>spring-libs-snapshot</id>
+			<username>${env.ARTIFACTORY_USR}</username>
+			<password>${env.ARTIFACTORY_PSW}</password>
+		</server>
+		<server>
+			<id>spring-libs-milestone</id>
+			<username>${env.ARTIFACTORY_USR}</username>
+			<password>${env.ARTIFACTORY_PSW}</password>
+		</server>
+		<server>
+			<id>spring-libs-release</id>
+			<username>${env.ARTIFACTORY_USR}</username>
+			<password>${env.ARTIFACTORY_PSW}</password>
+		</server>
+	</servers>
+
+</settings>

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.2.0-M2</version>
+		<version>4.0.0-M1</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb-distribution/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.2.0-M2</version>
+		<version>4.0.0-M1</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.2.0-M2</version>
+		<version>4.0.0-M1</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -87,6 +87,13 @@
 			<optional>true</optional>
 		</dependency>
 
+		<dependency>
+			<groupId>com.google.code.findbugs</groupId>
+			<artifactId>jsr305</artifactId>
+			<version>3.0.2</version>
+			<optional>true</optional>
+		</dependency>
+
 		<!-- reactive -->
 
 		<dependency>
@@ -115,27 +122,6 @@
 			<optional>true</optional>
 		</dependency>
 
-		<dependency>
-			<groupId>io.reactivex</groupId>
-			<artifactId>rxjava</artifactId>
-			<version>${rxjava}</version>
-			<optional>true</optional>
-		</dependency>
-
-		<dependency>
-			<groupId>io.reactivex</groupId>
-			<artifactId>rxjava-reactive-streams</artifactId>
-			<version>${rxjava-reactive-streams}</version>
-			<optional>true</optional>
-		</dependency>
-
-		<dependency>
-			<groupId>io.reactivex.rxjava2</groupId>
-			<artifactId>rxjava</artifactId>
-			<version>${rxjava2}</version>
-			<optional>true</optional>
-		</dependency>
-
 		<dependency>
 			<groupId>io.reactivex.rxjava3</groupId>
 			<artifactId>rxjava</artifactId>
@@ -145,12 +131,6 @@
 
 		<!-- CDI -->
 		<!-- Dependency order required to build against CDI 1.0 and test with CDI 2.0 -->
-		<dependency>
-			<groupId>org.apache.geronimo.specs</groupId>
-			<artifactId>geronimo-jcdi_2.0_spec</artifactId>
-			<version>1.0.1</version>
-			<scope>test</scope>
-		</dependency>
 
 		<dependency>
 			<groupId>javax.interceptor</groupId>
@@ -160,31 +140,48 @@
 		</dependency>
 
 		<dependency>
-			<groupId>javax.enterprise</groupId>
-			<artifactId>cdi-api</artifactId>
+			<groupId>jakarta.enterprise</groupId>
+			<artifactId>jakarta.enterprise.cdi-api</artifactId>
 			<version>${cdi}</version>
 			<scope>provided</scope>
 			<optional>true</optional>
 		</dependency>
 
 		<dependency>
-			<groupId>javax.annotation</groupId>
-			<artifactId>javax.annotation-api</artifactId>
-			<version>${javax-annotation-api}</version>
+			<groupId>jakarta.annotation</groupId>
+			<artifactId>jakarta.annotation-api</artifactId>
+			<version>${jakarta-annotation-api}</version>
 			<scope>test</scope>
 		</dependency>
 
 		<dependency>
 			<groupId>org.apache.openwebbeans</groupId>
 			<artifactId>openwebbeans-se</artifactId>
+			<classifier>jakarta</classifier>
+			<version>${webbeans}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.apache.openwebbeans</groupId>
+			<artifactId>openwebbeans-spi</artifactId>
+			<classifier>jakarta</classifier>
+			<version>${webbeans}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.apache.openwebbeans</groupId>
+			<artifactId>openwebbeans-impl</artifactId>
+			<classifier>jakarta</classifier>
 			<version>${webbeans}</version>
 			<scope>test</scope>
 		</dependency>
 
 		<!-- JSR 303 Validation -->
 		<dependency>
-			<groupId>javax.validation</groupId>
-			<artifactId>validation-api</artifactId>
+			<groupId>jakarta.validation</groupId>
+			<artifactId>jakarta.validation-api</artifactId>
 			<version>${validation}</version>
 			<optional>true</optional>
 		</dependency>
@@ -199,28 +196,30 @@
 		<dependency>
 			<groupId>org.hibernate</groupId>
 			<artifactId>hibernate-validator</artifactId>
-			<version>5.4.3.Final</version>
+			<version>7.0.1.Final</version>
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>jakarta.el</groupId>
+			<artifactId>jakarta.el-api</artifactId>
+			<version>4.0.0</version>
+			<scope>provided</scope>
+			<optional>true</optional>
+		</dependency>
+
 		<dependency>
 			<groupId>org.glassfish</groupId>
-			<artifactId>javax.el</artifactId>
-			<version>3.0.1-b11</version>
-			<scope>test</scope>
+			<artifactId>jakarta.el</artifactId>
+			<version>4.0.2</version>
+			<scope>provided</scope>
+			<optional>true</optional>
 		</dependency>
 
 		<dependency>
-			<groupId>joda-time</groupId>
-			<artifactId>joda-time</artifactId>
-			<version>${jodatime}</version>
-			<scope>test</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.threeten</groupId>
-			<artifactId>threetenbp</artifactId>
-			<version>${threetenbp}</version>
+			<groupId>jakarta.enterprise</groupId>
+			<artifactId>jakarta.enterprise.cdi-api</artifactId>
+			<scope>provided</scope>
 			<optional>true</optional>
 		</dependency>
 
@@ -230,13 +229,6 @@
 			<optional>true</optional>
 		</dependency>
 
-		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>jul-to-slf4j</artifactId>
-			<version>${slf4j}</version>
-			<scope>test</scope>
-		</dependency>
-
 		<dependency>
 			<groupId>nl.jqno.equalsverifier</groupId>
 			<artifactId>equalsverifier</artifactId>
@@ -272,9 +264,9 @@
 		</dependency>
 
 		<dependency>
-			<groupId>javax.transaction</groupId>
-			<artifactId>jta</artifactId>
-			<version>1.1</version>
+			<groupId>jakarta.transaction</groupId>
+			<artifactId>jakarta.transaction-api</artifactId>
+			<version>2.0.0</version>
 			<scope>test</scope>
 		</dependency>
 
@@ -310,6 +302,15 @@
 			<scope>test</scope>
 		</dependency>
 
+		<!-- jMolecules -->
+
+		<dependency>
+			<groupId>org.jmolecules</groupId>
+			<artifactId>jmolecules-ddd</artifactId>
+			<version>${jmolecules}</version>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 	<build>

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

@@ -0,0 +1,144 @@
+/*
+ * Copyright 2021 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.Arrays;
+
+import org.bson.Document;
+import org.bson.codecs.DocumentCodec;
+import org.bson.codecs.configuration.CodecRegistry;
+import org.springframework.data.mongodb.util.json.ParameterBindingDocumentCodec;
+import org.springframework.data.util.Lazy;
+import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
+
+/**
+ * A {@link MongoExpression} using the {@link ParameterBindingDocumentCodec} for parsing a raw ({@literal json})
+ * expression. The expression will be wrapped within <code>{ ... }</code> if necessary. The actual parsing and parameter
+ * binding of placeholders like {@code ?0} is delayed upon first call on the the target {@link Document} via
+ * {@link #toDocument()}.
+ * <br />
+ *
+ * <pre class="code">
+ * $toUpper : $name                -> { '$toUpper' : '$name' }
+ *
+ * { '$toUpper' : '$name' }        -> { '$toUpper' : '$name' }
+ *
+ * { '$toUpper' : '?0' }, "$name"  -> { '$toUpper' : '$name' }
+ * </pre>
+ *
+ * Some types might require a special {@link org.bson.codecs.Codec}. If so, make sure to provide a {@link CodecRegistry}
+ * containing the required {@link org.bson.codecs.Codec codec} via {@link #withCodecRegistry(CodecRegistry)}.
+ *
+ * @author Christoph Strobl
+ * @since 3.2
+ */
+public class BindableMongoExpression implements MongoExpression {
+
+	private final String expressionString;
+
+	private final @Nullable CodecRegistryProvider codecRegistryProvider;
+
+	private final @Nullable Object[] args;
+
+	private final Lazy<Document> target;
+
+	/**
+	 * Create a new instance of {@link BindableMongoExpression}.
+	 *
+	 * @param expression must not be {@literal null}.
+	 * @param args can be {@literal null}.
+	 */
+	public BindableMongoExpression(String expression, @Nullable Object[] args) {
+		this(expression, null, args);
+	}
+
+	/**
+	 * Create a new instance of {@link BindableMongoExpression}.
+	 *
+	 * @param expression must not be {@literal null}.
+	 * @param codecRegistryProvider can be {@literal null}.
+	 * @param args can be {@literal null}.
+	 */
+	public BindableMongoExpression(String expression, @Nullable CodecRegistryProvider codecRegistryProvider,
+			@Nullable Object[] args) {
+
+		this.expressionString = expression;
+		this.codecRegistryProvider = codecRegistryProvider;
+		this.args = args;
+		this.target = Lazy.of(this::parse);
+	}
+
+	/**
+	 * Provide the {@link CodecRegistry} used to convert expressions.
+	 *
+	 * @param codecRegistry must not be {@literal null}.
+	 * @return new instance of {@link BindableMongoExpression}.
+	 */
+	public BindableMongoExpression withCodecRegistry(CodecRegistry codecRegistry) {
+		return new BindableMongoExpression(expressionString, () -> codecRegistry, args);
+	}
+
+	/**
+	 * Provide the arguments to bind to the placeholders via their index.
+	 *
+	 * @param args must not be {@literal null}.
+	 * @return new instance of {@link BindableMongoExpression}.
+	 */
+	public BindableMongoExpression bind(Object... args) {
+		return new BindableMongoExpression(expressionString, codecRegistryProvider, args);
+	}
+
+	@Override
+	public Document toDocument() {
+		return target.get();
+	}
+
+	@Override
+	public String toString() {
+		return "BindableMongoExpression{" + "expressionString='" + expressionString + '\'' + ", args="
+				+ Arrays.toString(args) + '}';
+	}
+
+	private Document parse() {
+
+		String expression = wrapJsonIfNecessary(expressionString);
+
+		if (ObjectUtils.isEmpty(args)) {
+
+			if (codecRegistryProvider == null) {
+				return Document.parse(expression);
+			}
+
+			return Document.parse(expression, codecRegistryProvider.getCodecFor(Document.class)
+					.orElseGet(() -> new DocumentCodec(codecRegistryProvider.getCodecRegistry())));
+		}
+
+		ParameterBindingDocumentCodec codec = codecRegistryProvider == null ? new ParameterBindingDocumentCodec()
+				: new ParameterBindingDocumentCodec(codecRegistryProvider.getCodecRegistry());
+		return codec.decode(expression, args);
+	}
+
+	private static String wrapJsonIfNecessary(String json) {
+
+		if (StringUtils.hasText(json) && (json.startsWith("{") && json.endsWith("}"))) {
+			return json;
+		}
+
+		return "{" + json + "}";
+	}
+}

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

@@ -20,8 +20,8 @@ import org.springframework.util.StringUtils;
 
 /**
  * Helper class featuring helper methods for working with MongoDb collections.
- * <p/>
- * <p/>
+ * <br />
+ * <br />
  * Mainly intended for internal use within the framework.
  *
  * @author Thomas Risberg

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

@@ -30,7 +30,7 @@ import com.mongodb.client.MongoDatabase;
  * Helper class for managing a {@link MongoDatabase} instances via {@link MongoDatabaseFactory}. Used for obtaining
  * {@link ClientSession session bound} resources, such as {@link MongoDatabase} and
  * {@link com.mongodb.client.MongoCollection} suitable for transactional usage.
- * <p />
+ * <br />
  * <strong>Note:</strong> Intended for internal usage only.
  *
  * @author Christoph Strobl
@@ -43,7 +43,7 @@ public class MongoDatabaseUtils {
 	/**
 	 * Obtain the default {@link MongoDatabase database} form the given {@link MongoDatabaseFactory factory} using
 	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
 	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -56,7 +56,7 @@ public class MongoDatabaseUtils {
 
 	/**
 	 * Obtain the default {@link MongoDatabase database} form the given {@link MongoDatabaseFactory factory}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
 	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -71,7 +71,7 @@ public class MongoDatabaseUtils {
 	/**
 	 * Obtain the {@link MongoDatabase database} with given name form the given {@link MongoDatabaseFactory factory} using
 	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
 	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -85,7 +85,7 @@ public class MongoDatabaseUtils {
 
 	/**
 	 * Obtain the {@link MongoDatabase database} with given name form the given {@link MongoDatabaseFactory factory}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the current
 	 * {@link Thread} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -104,7 +104,8 @@ public class MongoDatabaseUtils {
 
 		Assert.notNull(factory, "Factory must not be null!");
 
-		if (!TransactionSynchronizationManager.isSynchronizationActive()) {
+		if (sessionSynchronization == SessionSynchronization.NEVER
+				|| !TransactionSynchronizationManager.isSynchronizationActive()) {
 			return StringUtils.hasText(dbName) ? factory.getMongoDatabase(dbName) : factory.getMongoDatabase();
 		}
 
@@ -192,19 +193,11 @@ public class MongoDatabaseUtils {
 			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) {
 
@@ -213,10 +206,6 @@ public class MongoDatabaseUtils {
 			}
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.support.ResourceHolderSynchronization#afterCompletion(int)
-		 */
 		@Override
 		public void afterCompletion(int status) {
 
@@ -227,10 +216,6 @@ public class MongoDatabaseUtils {
 			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) {
 

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

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2021 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;
+
+/**
+ * Wrapper object for MongoDB expressions like {@code $toUpper : $name} that manifest as {@link org.bson.Document} when
+ * passed on to the driver.
+ * <br />
+ * A set of predefined {@link MongoExpression expressions}, including a
+ * {@link org.springframework.data.mongodb.core.aggregation.AggregationSpELExpression SpEL based variant} for method
+ * like expressions (eg. {@code toUpper(name)}) are available via the
+ * {@link org.springframework.data.mongodb.core.aggregation Aggregation API}.
+ *
+ * @author Christoph Strobl
+ * @since 3.2
+ * @see org.springframework.data.mongodb.core.aggregation.ArithmeticOperators
+ * @see org.springframework.data.mongodb.core.aggregation.ArrayOperators
+ * @see org.springframework.data.mongodb.core.aggregation.ComparisonOperators
+ * @see org.springframework.data.mongodb.core.aggregation.ConditionalOperators
+ * @see org.springframework.data.mongodb.core.aggregation.ConvertOperators
+ * @see org.springframework.data.mongodb.core.aggregation.DateOperators
+ * @see org.springframework.data.mongodb.core.aggregation.ObjectOperators
+ * @see org.springframework.data.mongodb.core.aggregation.SetOperators
+ * @see org.springframework.data.mongodb.core.aggregation.StringOperators
+ */
+@FunctionalInterface
+public interface MongoExpression {
+
+	/**
+	 * Create a new {@link MongoExpression} from plain {@link String} (eg. {@code $toUpper : $name}). <br />
+	 * The given expression will be wrapped with <code>{ ... }</code> to match an actual MongoDB {@link org.bson.Document}
+	 * if necessary.
+	 *
+	 * @param expression must not be {@literal null}.
+	 * @return new instance of {@link MongoExpression}.
+	 */
+	static MongoExpression create(String expression) {
+		return new BindableMongoExpression(expression, null);
+	}
+
+	/**
+	 * Create a new {@link MongoExpression} from plain {@link String} containing placeholders (eg. {@code $toUpper : ?0})
+	 * that will be resolved on first call of {@link #toDocument()}. <br />
+	 * The given expression will be wrapped with <code>{ ... }</code> to match an actual MongoDB {@link org.bson.Document}
+	 * if necessary.
+	 *
+	 * @param expression must not be {@literal null}.
+	 * @return new instance of {@link MongoExpression}.
+	 */
+	static MongoExpression create(String expression, Object... args) {
+		return new BindableMongoExpression(expression, args);
+	}
+
+	/**
+	 * Obtain the native {@link org.bson.Document} representation.
+	 *
+	 * @return never {@literal null}.
+	 */
+	org.bson.Document toDocument();
+}

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

@@ -24,7 +24,7 @@ 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 />
+ * <br />
  * <strong>Note:</strong> Intended for internal usage only.
  *
  * @author Christoph Strobl

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

@@ -37,18 +37,18 @@ import com.mongodb.client.ClientSession;
 /**
  * A {@link org.springframework.transaction.PlatformTransactionManager} implementation that manages
  * {@link ClientSession} based transactions for a single {@link MongoDatabaseFactory}.
- * <p />
+ * <br />
  * Binds a {@link ClientSession} from the specified {@link MongoDatabaseFactory} to the thread.
- * <p />
+ * <br />
  * {@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 />
+ * <br />
  * Application code is required to retrieve the {@link com.mongodb.client.MongoDatabase} via
  * {@link MongoDatabaseUtils#getDatabase(MongoDatabaseFactory)} instead of a standard
  * {@link MongoDatabaseFactory#getMongoDatabase()} call. Spring classes such as
  * {@link org.springframework.data.mongodb.core.MongoTemplate} use this strategy implicitly.
- * <p />
+ * <br />
  * 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>
@@ -69,11 +69,11 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 
 	/**
 	 * Create a new {@link MongoTransactionManager} for bean-style usage.
-	 * <p />
+	 * <br />
 	 * <strong>Note:</strong>The {@link MongoDatabaseFactory db factory} has to be
 	 * {@link #setDbFactory(MongoDatabaseFactory) set} before using the instance. Use this constructor to prepare a
 	 * {@link MongoTransactionManager} via a {@link org.springframework.beans.factory.BeanFactory}.
-	 * <p />
+	 * <br />
 	 * Optionally it is possible to set default {@link TransactionOptions transaction options} defining
 	 * {@link com.mongodb.ReadConcern} and {@link com.mongodb.WriteConcern}.
 	 *
@@ -106,10 +106,6 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		this.options = options;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doGetTransaction()
-	 */
 	@Override
 	protected Object doGetTransaction() throws TransactionException {
 
@@ -118,19 +114,11 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		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 {
 
@@ -160,10 +148,6 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		TransactionSynchronizationManager.bindResource(getRequiredDbFactory(), resourceHolder);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doSuspend(java.lang.Object)
-	 */
 	@Override
 	protected Object doSuspend(Object transaction) throws TransactionException {
 
@@ -173,19 +157,11 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		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 {
 
@@ -212,8 +188,8 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 	 * 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 />
+	 * <pre>
 	 * <code>
-	 *     <pre>
 	 * int retries = 3;
 	 * do {
 	 *     try {
@@ -226,8 +202,8 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 	 *     }
 	 *     Thread.sleep(500);
 	 * } while (--retries > 0);
-	 *     </pre>
 	 * </code>
+	 * </pre>
 	 *
 	 * @param transactionObject never {@literal null}.
 	 * @throws Exception in case of transaction errors.
@@ -236,10 +212,6 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		transactionObject.commitTransaction();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doRollback(org.springframework.transaction.support.DefaultTransactionStatus)
-	 */
 	@Override
 	protected void doRollback(DefaultTransactionStatus status) throws TransactionException {
 
@@ -259,10 +231,6 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		}
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doSetRollbackOnly(org.springframework.transaction.support.DefaultTransactionStatus)
-	 */
 	@Override
 	protected void doSetRollbackOnly(DefaultTransactionStatus status) throws TransactionException {
 
@@ -270,10 +238,6 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		transactionObject.getRequiredResourceHolder().setRollbackOnly();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.transaction.support.AbstractPlatformTransactionManager#doCleanupAfterCompletion(java.lang.Object)
-	 */
 	@Override
 	protected void doCleanupAfterCompletion(Object transaction) {
 
@@ -325,19 +289,11 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 		return dbFactory;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.support.ResourceTransactionManager#getResourceFactory()
-	 */
 	@Override
 	public MongoDatabaseFactory getResourceFactory() {
 		return getRequiredDbFactory();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
-	 */
 	@Override
 	public void afterPropertiesSet() {
 		getRequiredDbFactory();
@@ -505,19 +461,11 @@ public class MongoTransactionManager extends AbstractPlatformTransactionManager
 			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/ReactiveMongoDatabaseUtils.java

@@ -36,7 +36,7 @@ import com.mongodb.reactivestreams.client.MongoDatabase;
  * Helper class for managing reactive {@link MongoDatabase} instances via {@link ReactiveMongoDatabaseFactory}. Used for
  * obtaining {@link ClientSession session bound} resources, such as {@link MongoDatabase} and {@link MongoCollection}
  * suitable for transactional usage.
- * <p />
+ * <br />
  * <strong>Note:</strong> Intended for internal usage only.
  *
  * @author Mark Paluch
@@ -75,7 +75,7 @@ public class ReactiveMongoDatabaseUtils {
 	/**
 	 * Obtain the default {@link MongoDatabase database} form the given {@link ReactiveMongoDatabaseFactory factory} using
 	 * {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
 	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -88,7 +88,7 @@ public class ReactiveMongoDatabaseUtils {
 
 	/**
 	 * Obtain the default {@link MongoDatabase database} form the given {@link ReactiveMongoDatabaseFactory factory}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
 	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -104,7 +104,7 @@ public class ReactiveMongoDatabaseUtils {
 	/**
 	 * Obtain the {@link MongoDatabase database} with given name form the given {@link ReactiveMongoDatabaseFactory
 	 * factory} using {@link SessionSynchronization#ON_ACTUAL_TRANSACTION native session synchronization}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
 	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -119,7 +119,7 @@ public class ReactiveMongoDatabaseUtils {
 	/**
 	 * Obtain the {@link MongoDatabase database} with given name form the given {@link ReactiveMongoDatabaseFactory
 	 * factory}.
-	 * <p />
+	 * <br />
 	 * Registers a {@link MongoSessionSynchronization MongoDB specific transaction synchronization} within the subscriber
 	 * {@link Context} if {@link TransactionSynchronizationManager#isSynchronizationActive() synchronization is active}.
 	 *
@@ -138,6 +138,10 @@ public class ReactiveMongoDatabaseUtils {
 
 		Assert.notNull(factory, "DatabaseFactory must not be null!");
 
+		if (sessionSynchronization == SessionSynchronization.NEVER) {
+			return getMongoDatabaseOrDefault(dbName, factory);
+		}
+
 		return TransactionSynchronizationManager.forCurrentTransaction()
 				.filter(TransactionSynchronizationManager::isSynchronizationActive) //
 				.flatMap(synchronizationManager -> {
@@ -210,19 +214,11 @@ public class ReactiveMongoDatabaseUtils {
 			this.resourceHolder = resourceHolder;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#shouldReleaseBeforeCompletion()
-		 */
 		@Override
 		protected boolean shouldReleaseBeforeCompletion() {
 			return false;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#processResourceAfterCommit(java.lang.Object)
-		 */
 		@Override
 		protected Mono<Void> processResourceAfterCommit(ReactiveMongoResourceHolder resourceHolder) {
 
@@ -233,10 +229,6 @@ public class ReactiveMongoDatabaseUtils {
 			return Mono.empty();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#afterCompletion(int)
-		 */
 		@Override
 		public Mono<Void> afterCompletion(int status) {
 
@@ -252,10 +244,6 @@ public class ReactiveMongoDatabaseUtils {
 			});
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.reactive.ReactiveResourceSynchronization#releaseResource(java.lang.Object, java.lang.Object)
-		 */
 		@Override
 		protected Mono<Void> releaseResource(ReactiveMongoResourceHolder resourceHolder, Object resourceKey) {
 

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

@@ -24,7 +24,7 @@ import com.mongodb.reactivestreams.client.ClientSession;
 /**
  * MongoDB specific resource holder, wrapping a {@link ClientSession}. {@link ReactiveMongoTransactionManager} binds
  * instances of this class to the subscriber context.
- * <p />
+ * <br />
  * <strong>Note:</strong> Intended for internal usage only.
  *
  * @author Mark Paluch

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

@@ -38,21 +38,21 @@ import com.mongodb.reactivestreams.client.ClientSession;
  * A {@link org.springframework.transaction.ReactiveTransactionManager} implementation that manages
  * {@link com.mongodb.reactivestreams.client.ClientSession} based transactions for a single
  * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory}.
- * <p />
+ * <br />
  * Binds a {@link ClientSession} from the specified
  * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory} to the subscriber
  * {@link reactor.util.context.Context}.
- * <p />
+ * <br />
  * {@link org.springframework.transaction.TransactionDefinition#isReadOnly() Readonly} transactions operate on a
  * {@link ClientSession} and enable causal consistency, and also {@link ClientSession#startTransaction() start},
  * {@link com.mongodb.reactivestreams.client.ClientSession#commitTransaction() commit} or
  * {@link ClientSession#abortTransaction() abort} a transaction.
- * <p />
+ * <br />
  * Application code is required to retrieve the {@link com.mongodb.reactivestreams.client.MongoDatabase} via
  * {@link org.springframework.data.mongodb.ReactiveMongoDatabaseUtils#getDatabase(ReactiveMongoDatabaseFactory)} instead
  * of a standard {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory#getMongoDatabase()} call. Spring
  * classes such as {@link org.springframework.data.mongodb.core.ReactiveMongoTemplate} use this strategy implicitly.
- * <p />
+ * <br />
  * By default failure of a {@literal commit} operation raises a {@link TransactionSystemException}. You can override
  * {@link #doCommit(TransactionSynchronizationManager, ReactiveMongoTransactionObject)} to implement the
  * <a href="https://docs.mongodb.com/manual/core/transactions/#retry-commit-operation">Retry Commit Operation</a>
@@ -71,11 +71,11 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 
 	/**
 	 * Create a new {@link ReactiveMongoTransactionManager} for bean-style usage.
-	 * <p />
+	 * <br />
 	 * <strong>Note:</strong>The {@link org.springframework.data.mongodb.ReactiveMongoDatabaseFactory db factory} has to
 	 * be {@link #setDatabaseFactory(ReactiveMongoDatabaseFactory)} set} before using the instance. Use this constructor
 	 * to prepare a {@link ReactiveMongoTransactionManager} via a {@link org.springframework.beans.factory.BeanFactory}.
-	 * <p />
+	 * <br />
 	 * Optionally it is possible to set default {@link TransactionOptions transaction options} defining
 	 * {@link com.mongodb.ReadConcern} and {@link com.mongodb.WriteConcern}.
 	 *
@@ -110,10 +110,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		this.options = options;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doGetTransaction(org.springframework.transaction.reactive.TransactionSynchronizationManager)
-	 */
 	@Override
 	protected Object doGetTransaction(TransactionSynchronizationManager synchronizationManager)
 			throws TransactionException {
@@ -123,19 +119,11 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		return new ReactiveMongoTransactionObject(resourceHolder);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#isExistingTransaction(java.lang.Object)
-	 */
 	@Override
 	protected boolean isExistingTransaction(Object transaction) throws TransactionException {
 		return extractMongoTransaction(transaction).hasResourceHolder();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doBegin(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object, org.springframework.transaction.TransactionDefinition)
-	 */
 	@Override
 	protected Mono<Void> doBegin(TransactionSynchronizationManager synchronizationManager, Object transaction,
 			TransactionDefinition definition) throws TransactionException {
@@ -175,10 +163,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doSuspend(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object)
-	 */
 	@Override
 	protected Mono<Object> doSuspend(TransactionSynchronizationManager synchronizationManager, Object transaction)
 			throws TransactionException {
@@ -192,10 +176,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doResume(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object, java.lang.Object)
-	 */
 	@Override
 	protected Mono<Void> doResume(TransactionSynchronizationManager synchronizationManager, @Nullable Object transaction,
 			Object suspendedResources) {
@@ -203,10 +183,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 				.fromRunnable(() -> synchronizationManager.bindResource(getRequiredDatabaseFactory(), suspendedResources));
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doCommit(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
-	 */
 	@Override
 	protected final Mono<Void> doCommit(TransactionSynchronizationManager synchronizationManager,
 			GenericReactiveTransaction status) throws TransactionException {
@@ -243,10 +219,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		return transactionObject.commitTransaction();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doRollback(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
-	 */
 	@Override
 	protected Mono<Void> doRollback(TransactionSynchronizationManager synchronizationManager,
 			GenericReactiveTransaction status) {
@@ -268,10 +240,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doSetRollbackOnly(org.springframework.transaction.reactive.TransactionSynchronizationManager, org.springframework.transaction.reactive.GenericReactiveTransaction)
-	 */
 	@Override
 	protected Mono<Void> doSetRollbackOnly(TransactionSynchronizationManager synchronizationManager,
 			GenericReactiveTransaction status) throws TransactionException {
@@ -282,10 +250,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.transaction.reactive.AbstractReactiveTransactionManager#doCleanupAfterCompletion(org.springframework.transaction.reactive.TransactionSynchronizationManager, java.lang.Object)
-	 */
 	@Override
 	protected Mono<Void> doCleanupAfterCompletion(TransactionSynchronizationManager synchronizationManager,
 			Object transaction) {
@@ -340,10 +304,6 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 		return databaseFactory;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
-	 */
 	@Override
 	public void afterPropertiesSet() {
 		getRequiredDatabaseFactory();
@@ -509,19 +469,11 @@ public class ReactiveMongoTransactionManager extends AbstractReactiveTransaction
 			return session;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.support.SmartTransactionObject#isRollbackOnly()
-		 */
 		@Override
 		public boolean isRollbackOnly() {
 			return this.resourceHolder != null && this.resourceHolder.isRollbackOnly();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.transaction.support.SmartTransactionObject#flush()
-		 */
 		@Override
 		public void flush() {
 			throw new UnsupportedOperationException("flush() not supported");

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

@@ -35,7 +35,7 @@ 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 />
+ * <br />
  * 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.
@@ -95,10 +95,6 @@ public class SessionAwareMethodInterceptor<D, C> implements MethodInterceptor {
 		this.sessionType = sessionType;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.aopalliance.intercept.MethodInterceptor(org.aopalliance.intercept.MethodInvocation)
-	 */
 	@Nullable
 	@Override
 	public Object invoke(MethodInvocation methodInvocation) throws Throwable {

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

@@ -15,13 +15,20 @@
  */
 package org.springframework.data.mongodb;
 
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
+
 /**
- * {@link SessionSynchronization} is used along with {@link org.springframework.data.mongodb.core.MongoTemplate} to
- * define in which type of transactions to participate if any.
+ * {@link SessionSynchronization} is used along with {@code MongoTemplate} to define in which type of transactions to
+ * participate if any.
  *
  * @author Christoph Strobl
  * @author Mark Paluch
  * @since 2.1
+ * @see MongoTemplate#setSessionSynchronization(SessionSynchronization)
+ * @see MongoDatabaseUtils#getDatabase(MongoDatabaseFactory, SessionSynchronization)
+ * @see ReactiveMongoTemplate#setSessionSynchronization(SessionSynchronization)
+ * @see ReactiveMongoDatabaseUtils#getDatabase(ReactiveMongoDatabaseFactory, SessionSynchronization)
  */
 public enum SessionSynchronization {
 
@@ -34,5 +41,12 @@ public enum SessionSynchronization {
 	/**
 	 * Synchronize with native MongoDB transactions initiated via {@link MongoTransactionManager}.
 	 */
-	ON_ACTUAL_TRANSACTION;
+	ON_ACTUAL_TRANSACTION,
+
+	/**
+	 * Do not participate in ongoing transactions.
+	 *
+	 * @since 3.2.5
+	 */
+	NEVER;
 }

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

@@ -15,8 +15,8 @@
  */
 package org.springframework.data.mongodb;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.data.util.Version;
 import org.springframework.util.StringUtils;
 
@@ -31,7 +31,7 @@ import com.mongodb.MongoDriverInformation;
  */
 public class SpringDataMongoDB {
 
-	private static final Logger LOGGER = LoggerFactory.getLogger(SpringDataMongoDB.class);
+	private static final Log LOGGER = LogFactory.getLog(SpringDataMongoDB.class);
 
 	private static final Version FALLBACK_VERSION = new Version(3);
 	private static final MongoDriverInformation DRIVER_INFORMATION = MongoDriverInformation
@@ -48,7 +48,7 @@ public class SpringDataMongoDB {
 
 	/**
 	 * Fetches the "Implementation-Version" manifest attribute from the jar file.
-	 * <p />
+	 * <br />
 	 * Note that some ClassLoaders do not expose the package metadata, hence this class might not be able to determine the
 	 * version in all environments. In this case the current Major version is returned as a fallback.
 	 *
@@ -68,7 +68,7 @@ public class SpringDataMongoDB {
 		try {
 			return Version.parse(versionString);
 		} catch (Exception e) {
-			LOGGER.debug("Cannot read Spring Data MongoDB version '{}'.", versionString);
+			LOGGER.debug(String.format("Cannot read Spring Data MongoDB version '%s'.", versionString));
 		}
 
 		return FALLBACK_VERSION;

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

@@ -30,10 +30,6 @@ import com.mongodb.ConnectionString;
  */
 public class ConnectionStringPropertyEditor extends PropertyEditorSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
-	 */
 	@Override
 	public void setAsText(@Nullable String connectionString) {
 

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

@@ -34,10 +34,6 @@ import org.w3c.dom.Element;
  */
 class GridFsTemplateParser 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)
-	 */
 	@Override
 	protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)
 			throws BeanDefinitionStoreException {
@@ -46,10 +42,6 @@ class GridFsTemplateParser extends AbstractBeanDefinitionParser {
 		return StringUtils.hasText(id) ? id : BeanNames.GRID_FS_TEMPLATE_BEAN_NAME;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#parseInternal(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
-	 */
 	@Override
 	protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
 

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

@@ -80,7 +80,7 @@ import org.w3c.dom.Element;
 public class MappingMongoConverterParser implements BeanDefinitionParser {
 
 	private static final String BASE_PACKAGE = "base-package";
-	private static final boolean JSR_303_PRESENT = ClassUtils.isPresent("javax.validation.Validator",
+	private static final boolean JSR_303_PRESENT = ClassUtils.isPresent("jakarta.validation.Validator",
 			MappingMongoConverterParser.class.getClassLoader());
 
 	/* (non-Javadoc)
@@ -376,10 +376,6 @@ public class MappingMongoConverterParser implements BeanDefinitionParser {
 			this.delegates = new HashSet<>(Arrays.asList(filters));
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.core.type.filter.TypeFilter#match(org.springframework.core.type.classreading.MetadataReader, org.springframework.core.type.classreading.MetadataReaderFactory)
-		 */
 		public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
 				throws IOException {
 

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

@@ -47,28 +47,16 @@ public class MongoAuditingBeanDefinitionParser extends AbstractSingleBeanDefinit
 	private static boolean PROJECT_REACTOR_AVAILABLE = ClassUtils.isPresent("reactor.core.publisher.Mono",
 			MongoAuditingRegistrar.class.getClassLoader());
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser#getBeanClass(org.w3c.dom.Element)
-	 */
 	@Override
 	protected Class<?> getBeanClass(Element element) {
 		return AuditingEntityCallback.class;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#shouldGenerateId()
-	 */
 	@Override
 	protected boolean shouldGenerateId() {
 		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)
-	 */
 	@Override
 	protected void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
 

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

@@ -18,6 +18,7 @@ package org.springframework.data.mongodb.config;
 import java.lang.annotation.Annotation;
 
 import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.RuntimeBeanReference;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
@@ -27,6 +28,8 @@ import org.springframework.data.auditing.IsNewAwareAuditingHandler;
 import org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport;
 import org.springframework.data.auditing.config.AuditingConfiguration;
 import org.springframework.data.config.ParsingUtils;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.core.mapping.event.AuditingEntityCallback;
 import org.springframework.util.Assert;
 
@@ -39,28 +42,16 @@ import org.springframework.util.Assert;
  */
 class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAnnotation()
-	 */
 	@Override
 	protected Class<? extends Annotation> getAnnotation() {
 		return EnableMongoAuditing.class;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditingHandlerBeanName()
-	 */
 	@Override
 	protected String getAuditingHandlerBeanName() {
 		return "mongoAuditingHandler";
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#registerBeanDefinitions(org.springframework.core.type.AnnotationMetadata, org.springframework.beans.factory.support.BeanDefinitionRegistry)
-	 */
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry registry) {
 
@@ -70,10 +61,6 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 		super.registerBeanDefinitions(annotationMetadata, registry);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditHandlerBeanDefinitionBuilder(org.springframework.data.auditing.config.AuditingConfiguration)
-	 */
 	@Override
 	protected BeanDefinitionBuilder getAuditHandlerBeanDefinitionBuilder(AuditingConfiguration configuration) {
 
@@ -81,17 +68,13 @@ class MongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
 		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(IsNewAwareAuditingHandler.class);
 
-		BeanDefinitionBuilder definition = BeanDefinitionBuilder.genericBeanDefinition(PersistentEntitiesFactoryBean.class);
-		definition.setAutowireMode(AbstractBeanDefinition.AUTOWIRE_CONSTRUCTOR);
+		BeanDefinitionBuilder definition = BeanDefinitionBuilder.genericBeanDefinition(org.springframework.data.repository.config.PersistentEntitiesFactoryBean.class);
+		definition.addConstructorArgValue(new RuntimeBeanReference(MappingContext.class));
 
 		builder.addConstructorArgValue(definition.getBeanDefinition());
 		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)
-	 */
 	@Override
 	protected void registerAuditListenerBeanDefinition(BeanDefinition auditingHandlerDefinition,
 			BeanDefinitionRegistry registry) {

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

@@ -35,10 +35,6 @@ import org.w3c.dom.Element;
  */
 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)
-	 */
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 
 		Object source = parserContext.extractSource(element);

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

@@ -26,7 +26,6 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.type.filter.AnnotationTypeFilter;
-import org.springframework.data.annotation.Persistent;
 import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.mapping.model.CamelCaseAbbreviatingFieldNamingStrategy;
 import org.springframework.data.mapping.model.FieldNamingStrategy;
@@ -140,8 +139,7 @@ public abstract class MongoConfigurationSupport {
 	}
 
 	/**
-	 * Scans the given base package for entities, i.e. MongoDB specific types annotated with {@link Document} and
-	 * {@link Persistent}.
+	 * Scans the given base package for entities, i.e. MongoDB specific types annotated with {@link Document}.
 	 *
 	 * @param basePackage must not be {@literal null}.
 	 * @return
@@ -161,7 +159,6 @@ public abstract class MongoConfigurationSupport {
 			ClassPathScanningCandidateComponentProvider componentProvider = new ClassPathScanningCandidateComponentProvider(
 					false);
 			componentProvider.addIncludeFilter(new AnnotationTypeFilter(Document.class));
-			componentProvider.addIncludeFilter(new AnnotationTypeFilter(Persistent.class));
 
 			for (BeanDefinition candidate : componentProvider.findCandidateComponents(basePackage)) {
 
@@ -175,8 +172,7 @@ public abstract class MongoConfigurationSupport {
 
 	/**
 	 * Configures whether to abbreviate field names for domain objects by configuring a
-	 * {@link CamelCaseAbbreviatingFieldNamingStrategy} on the {@link MongoMappingContext} instance created. For advanced
-	 * customization needs, consider overriding {@link #mappingMongoConverter()}.
+	 * {@link CamelCaseAbbreviatingFieldNamingStrategy} on the {@link MongoMappingContext} instance created.
 	 *
 	 * @return
 	 */

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

@@ -51,10 +51,6 @@ public class MongoCredentialPropertyEditor extends PropertyEditorSupport {
 	private static final String OPTIONS_DELIMITER = "?";
 	private static final String OPTION_VALUE_DELIMITER = "&";
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
-	 */
 	@Override
 	public void setAsText(@Nullable String text) throws IllegalArgumentException {
 

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

@@ -62,10 +62,6 @@ public class MongoDbFactoryParser extends AbstractBeanDefinitionParser {
 		MONGO_URI_ALLOWED_ADDITIONAL_ATTRIBUTES = Collections.unmodifiableSet(mongoUriAllowedAdditionalAttributes);
 	}
 
-	/*
-	 * (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)
-	 */
 	@Override
 	protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)
 			throws BeanDefinitionStoreException {
@@ -74,10 +70,6 @@ public class MongoDbFactoryParser extends AbstractBeanDefinitionParser {
 		return StringUtils.hasText(id) ? id : BeanNames.DB_FACTORY_BEAN_NAME;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#parseInternal(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
-	 */
 	@Override
 	protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
 

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

@@ -26,10 +26,6 @@ import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
  */
 public class MongoNamespaceHandler extends NamespaceHandlerSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.NamespaceHandler#init()
-	 */
 	public void init() {
 
 		registerBeanDefinitionParser("mapping-converter", new MappingMongoConverterParser());

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

@@ -22,9 +22,12 @@ import java.util.Map;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.CustomEditorConfigurer;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionValidationException;
 import org.springframework.beans.factory.support.ManagedMap;
 import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.data.mongodb.core.MongoClientSettingsFactoryBean;
+import org.springframework.data.mongodb.core.MongoServerApiFactoryBean;
+import org.springframework.util.StringUtils;
 import org.springframework.util.xml.DomUtils;
 import org.w3c.dom.Element;
 
@@ -112,6 +115,20 @@ abstract class MongoParsingUtils {
 		// Field level encryption
 		setPropertyReference(clientOptionsDefBuilder, settingsElement, "encryption-settings-ref", "autoEncryptionSettings");
 
+		// ServerAPI
+		if (StringUtils.hasText(settingsElement.getAttribute("server-api-version"))) {
+
+			MongoServerApiFactoryBean serverApiFactoryBean = new MongoServerApiFactoryBean();
+			serverApiFactoryBean.setVersion(settingsElement.getAttribute("server-api-version"));
+			try {
+				clientOptionsDefBuilder.addPropertyValue("serverApi", serverApiFactoryBean.getObject());
+			} catch (Exception exception) {
+				throw new BeanDefinitionValidationException("Non parsable server-api.", exception);
+			}
+		} else {
+			setPropertyReference(clientOptionsDefBuilder, settingsElement, "server-api-ref", "serverApi");
+		}
+
 		// and the rest
 
 		mongoClientBuilder.addPropertyValue("mongoClientSettings", clientOptionsDefBuilder.getBeanDefinition());

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

@@ -39,10 +39,6 @@ import org.w3c.dom.Element;
  */
 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)
-	 */
 	@Override
 	protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)
 			throws BeanDefinitionStoreException {
@@ -51,10 +47,6 @@ class MongoTemplateParser extends AbstractBeanDefinitionParser {
 		return StringUtils.hasText(id) ? id : BeanNames.MONGO_TEMPLATE_BEAN_NAME;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.AbstractBeanDefinitionParser#parseInternal(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
-	 */
 	@Override
 	protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
 

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

@@ -28,7 +28,7 @@ import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
  * @author Christoph Strobl
  * @since 3.1
  */
-class PersistentEntitiesFactoryBean implements FactoryBean<PersistentEntities> {
+public class PersistentEntitiesFactoryBean implements FactoryBean<PersistentEntities> {
 
 	private final MappingMongoConverter converter;
 
@@ -41,19 +41,11 @@ class PersistentEntitiesFactoryBean implements FactoryBean<PersistentEntities> {
 		this.converter = converter;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.FactoryBean#getObject()
-	 */
 	@Override
 	public PersistentEntities getObject() {
 		return PersistentEntities.of(converter.getMappingContext());
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.FactoryBean#getObjectType()
-	 */
 	@Override
 	public Class<?> getObjectType() {
 		return PersistentEntities.class;

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

@@ -38,28 +38,16 @@ import org.springframework.util.Assert;
  */
 class ReactiveMongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAnnotation()
-	 */
 	@Override
 	protected Class<? extends Annotation> getAnnotation() {
 		return EnableReactiveMongoAuditing.class;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditingHandlerBeanName()
-	 */
 	@Override
 	protected String getAuditingHandlerBeanName() {
 		return "reactiveMongoAuditingHandler";
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport#getAuditHandlerBeanDefinitionBuilder(org.springframework.data.auditing.config.AuditingConfiguration)
-	 */
 	@Override
 	protected BeanDefinitionBuilder getAuditHandlerBeanDefinitionBuilder(AuditingConfiguration configuration) {
 
@@ -74,10 +62,6 @@ class ReactiveMongoAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupp
 		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)
-	 */
 	@Override
 	protected void registerAuditListenerBeanDefinition(BeanDefinition auditingHandlerDefinition,
 			BeanDefinitionRegistry registry) {

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

@@ -32,10 +32,6 @@ import com.mongodb.ReadConcernLevel;
  */
 public class ReadConcernPropertyEditor extends PropertyEditorSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.xml.BeanDefinitionParser#parse(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext)
-	 */
 	@Override
 	public void setAsText(@Nullable String readConcernString) {
 

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

@@ -29,10 +29,6 @@ import com.mongodb.ReadPreference;
  */
 public class ReadPreferencePropertyEditor extends PropertyEditorSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
-	 */
 	@Override
 	public void setAsText(@Nullable String readPreferenceString) throws IllegalArgumentException {
 

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

@@ -21,8 +21,8 @@ import java.net.UnknownHostException;
 import java.util.HashSet;
 import java.util.Set;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -43,13 +43,9 @@ public class ServerAddressPropertyEditor extends PropertyEditorSupport {
 	 * A port is a number without a leading 0 at the end of the address that is proceeded by just a single :.
 	 */
 	private static final String HOST_PORT_SPLIT_PATTERN = "(?<!:):(?=[123456789]\\d*$)";
-	private static final String COULD_NOT_PARSE_ADDRESS_MESSAGE = "Could not parse address {} '{}'. Check your replica set configuration!";
-	private static final Logger LOG = LoggerFactory.getLogger(ServerAddressPropertyEditor.class);
+	private static final String COULD_NOT_PARSE_ADDRESS_MESSAGE = "Could not parse address %s '%s'. Check your replica set configuration!";
+	private static final Log LOG = LogFactory.getLog(ServerAddressPropertyEditor.class);
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
-	 */
 	@Override
 	public void setAsText(@Nullable String replicaSetString) {
 
@@ -88,14 +84,18 @@ public class ServerAddressPropertyEditor extends PropertyEditorSupport {
 	private ServerAddress parseServerAddress(String source) {
 
 		if (!StringUtils.hasText(source)) {
-			LOG.warn(COULD_NOT_PARSE_ADDRESS_MESSAGE, "source", source);
+			if(LOG.isWarnEnabled()) {
+				LOG.warn(String.format(COULD_NOT_PARSE_ADDRESS_MESSAGE, "source", source));
+			}
 			return null;
 		}
 
 		String[] hostAndPort = extractHostAddressAndPort(source.trim());
 
 		if (hostAndPort.length > 2) {
-			LOG.warn(COULD_NOT_PARSE_ADDRESS_MESSAGE, "source", source);
+			if(LOG.isWarnEnabled()) {
+				LOG.warn(String.format(COULD_NOT_PARSE_ADDRESS_MESSAGE, "source", source));
+			}
 			return null;
 		}
 
@@ -105,9 +105,13 @@ public class ServerAddressPropertyEditor extends PropertyEditorSupport {
 
 			return port == null ? new ServerAddress(hostAddress) : new ServerAddress(hostAddress, port);
 		} catch (UnknownHostException e) {
-			LOG.warn(COULD_NOT_PARSE_ADDRESS_MESSAGE, "host", hostAndPort[0]);
+			if(LOG.isWarnEnabled()) {
+				LOG.warn(String.format(COULD_NOT_PARSE_ADDRESS_MESSAGE, "host", hostAndPort[0]));
+			}
 		} catch (NumberFormatException e) {
-			LOG.warn(COULD_NOT_PARSE_ADDRESS_MESSAGE, "port", hostAndPort[1]);
+			if(LOG.isWarnEnabled()) {
+				LOG.warn(String.format(COULD_NOT_PARSE_ADDRESS_MESSAGE, "port", hostAndPort[1]));
+			}
 		}
 
 		return null;

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

@@ -26,10 +26,6 @@ import com.mongodb.WriteConcern;
  */
 public class StringToWriteConcernConverter implements Converter<String, WriteConcern> {
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
-	 */
 	public WriteConcern convert(String source) {
 
 		WriteConcern writeConcern = WriteConcern.valueOf(source);

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

@@ -29,10 +29,6 @@ import org.springframework.util.StringUtils;
  */
 public class UUidRepresentationPropertyEditor extends PropertyEditorSupport {
 
-	/*
-	 * (non-Javadoc)
-	 * @see java.beans.PropertyEditorSupport#setAsText(java.lang.String)
-	 */
 	@Override
 	public void setAsText(@Nullable String value) {
 

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

@@ -27,6 +27,7 @@ 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.AggregationOptions.DomainTypeMapping;
 import org.springframework.data.mongodb.core.aggregation.CountOperation;
 import org.springframework.data.mongodb.core.aggregation.RelaxedTypeBasedAggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.TypeBasedAggregationOperationContext;
@@ -36,6 +37,7 @@ 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.data.util.Lazy;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
@@ -52,41 +54,46 @@ class AggregationUtil {
 
 	QueryMapper queryMapper;
 	MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	Lazy<AggregationOperationContext> untypedMappingContext;
 
 	AggregationUtil(QueryMapper queryMapper,
 			MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext) {
 
 		this.queryMapper = queryMapper;
 		this.mappingContext = mappingContext;
+		this.untypedMappingContext = Lazy
+				.of(() -> new RelaxedTypeBasedAggregationOperationContext(Object.class, mappingContext, queryMapper));
 	}
 
-	/**
-	 * Prepare the {@link AggregationOperationContext} for a given aggregation by either returning the context itself it
-	 * is not {@literal null}, create a {@link TypeBasedAggregationOperationContext} if the aggregation contains type
-	 * information (is a {@link TypedAggregation}) or use the {@link Aggregation#DEFAULT_CONTEXT}.
-	 *
-	 * @param aggregation must not be {@literal null}.
-	 * @param context can be {@literal null}.
-	 * @return the root {@link AggregationOperationContext} to use.
-	 */
-	AggregationOperationContext prepareAggregationContext(Aggregation aggregation,
-			@Nullable AggregationOperationContext context) {
+	AggregationOperationContext createAggregationContext(Aggregation aggregation, @Nullable Class<?> inputType) {
 
-		if (context != null) {
-			return context;
+		DomainTypeMapping domainTypeMapping = aggregation.getOptions().getDomainTypeMapping();
+
+		if (domainTypeMapping == DomainTypeMapping.NONE) {
+			return Aggregation.DEFAULT_CONTEXT;
 		}
 
 		if (!(aggregation instanceof TypedAggregation)) {
-			return new RelaxedTypeBasedAggregationOperationContext(Object.class, mappingContext, queryMapper);
-		}
 
-		Class<?> inputType = ((TypedAggregation) aggregation).getInputType();
+			if(inputType == null) {
+				return untypedMappingContext.get();
+			}
+
+			if (domainTypeMapping == DomainTypeMapping.STRICT
+					&& !aggregation.getPipeline().containsUnionWith()) {
+				return new TypeBasedAggregationOperationContext(inputType, mappingContext, queryMapper);
+			}
 
-		if (aggregation.getPipeline().containsUnionWith()) {
 			return new RelaxedTypeBasedAggregationOperationContext(inputType, mappingContext, queryMapper);
 		}
 
-		return new TypeBasedAggregationOperationContext(inputType, mappingContext, queryMapper);
+		inputType = ((TypedAggregation<?>) aggregation).getInputType();
+		if (domainTypeMapping == DomainTypeMapping.STRICT
+				&& !aggregation.getPipeline().containsUnionWith()) {
+			return new TypeBasedAggregationOperationContext(inputType, mappingContext, queryMapper);
+		}
+
+		return new RelaxedTypeBasedAggregationOperationContext(inputType, mappingContext, queryMapper);
 	}
 
 	/**
@@ -125,53 +132,6 @@ 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

@@ -189,10 +189,6 @@ public class ChangeStreamEvent<T> {
 				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

@@ -242,13 +242,13 @@ public class ChangeStreamOptions {
 
 		/**
 		 * Set the filter to apply.
-		 * <p/>
+		 * <br />
 		 * 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/>
+		 * <br />
 		 * Use {@link org.springframework.data.mongodb.core.aggregation.TypedAggregation} to ensure filter expressions are
 		 * mapped to domain type fields.
 		 *

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

@@ -17,8 +17,11 @@ package org.springframework.data.mongodb.core;
 
 import java.util.Optional;
 
+import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.data.mongodb.core.timeseries.Granularity;
+import org.springframework.data.mongodb.core.timeseries.GranularityDefinition;
 import org.springframework.data.mongodb.core.validation.Validator;
 import org.springframework.data.util.Optionals;
 import org.springframework.lang.Nullable;
@@ -42,6 +45,7 @@ public class CollectionOptions {
 	private @Nullable Boolean capped;
 	private @Nullable Collation collation;
 	private ValidationOptions validationOptions;
+	private @Nullable TimeSeriesOptions timeSeriesOptions;
 
 	/**
 	 * Constructs a new <code>CollectionOptions</code> instance.
@@ -54,17 +58,19 @@ public class CollectionOptions {
 	 */
 	@Deprecated
 	public CollectionOptions(@Nullable Long size, @Nullable Long maxDocuments, @Nullable Boolean capped) {
-		this(size, maxDocuments, capped, null, ValidationOptions.none());
+		this(size, maxDocuments, capped, null, ValidationOptions.none(), null);
 	}
 
 	private CollectionOptions(@Nullable Long size, @Nullable Long maxDocuments, @Nullable Boolean capped,
-			@Nullable Collation collation, ValidationOptions validationOptions) {
+			@Nullable Collation collation, ValidationOptions validationOptions,
+			@Nullable TimeSeriesOptions timeSeriesOptions) {
 
 		this.maxDocuments = maxDocuments;
 		this.size = size;
 		this.capped = capped;
 		this.collation = collation;
 		this.validationOptions = validationOptions;
+		this.timeSeriesOptions = timeSeriesOptions;
 	}
 
 	/**
@@ -78,7 +84,7 @@ public class CollectionOptions {
 
 		Assert.notNull(collation, "Collation must not be null!");
 
-		return new CollectionOptions(null, null, null, collation, ValidationOptions.none());
+		return new CollectionOptions(null, null, null, collation, ValidationOptions.none(), null);
 	}
 
 	/**
@@ -88,7 +94,21 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public static CollectionOptions empty() {
-		return new CollectionOptions(null, null, null, null, ValidationOptions.none());
+		return new CollectionOptions(null, null, null, null, ValidationOptions.none(), null);
+	}
+
+	/**
+	 * Quick way to set up {@link CollectionOptions} for a Time Series collection. For more advanced settings use
+	 * {@link #timeSeries(TimeSeriesOptions)}.
+	 *
+	 * @param timeField The name of the property which contains the date in each time series document. Must not be
+	 *          {@literal null}.
+	 * @return new instance of {@link CollectionOptions}.
+	 * @see #timeSeries(TimeSeriesOptions)
+	 * @since 3.3
+	 */
+	public static CollectionOptions timeSeries(String timeField) {
+		return empty().timeSeries(TimeSeriesOptions.timeSeries(timeField));
 	}
 
 	/**
@@ -99,7 +119,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions capped() {
-		return new CollectionOptions(size, maxDocuments, true, collation, validationOptions);
+		return new CollectionOptions(size, maxDocuments, true, collation, validationOptions, null);
 	}
 
 	/**
@@ -110,7 +130,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions maxDocuments(long maxDocuments) {
-		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions, timeSeriesOptions);
 	}
 
 	/**
@@ -121,7 +141,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions size(long size) {
-		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions, timeSeriesOptions);
 	}
 
 	/**
@@ -132,7 +152,7 @@ public class CollectionOptions {
 	 * @since 2.0
 	 */
 	public CollectionOptions collation(@Nullable Collation collation) {
-		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions, timeSeriesOptions);
 	}
 
 	/**
@@ -252,7 +272,20 @@ public class CollectionOptions {
 	public CollectionOptions validation(ValidationOptions validationOptions) {
 
 		Assert.notNull(validationOptions, "ValidationOptions must not be null!");
-		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions);
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions, timeSeriesOptions);
+	}
+
+	/**
+	 * Create new {@link CollectionOptions} with the given {@link TimeSeriesOptions}.
+	 *
+	 * @param timeSeriesOptions must not be {@literal null}.
+	 * @return new instance of {@link CollectionOptions}.
+	 * @since 3.3
+	 */
+	public CollectionOptions timeSeries(TimeSeriesOptions timeSeriesOptions) {
+
+		Assert.notNull(timeSeriesOptions, "TimeSeriesOptions must not be null!");
+		return new CollectionOptions(size, maxDocuments, capped, collation, validationOptions, timeSeriesOptions);
 	}
 
 	/**
@@ -303,6 +336,16 @@ public class CollectionOptions {
 		return validationOptions.isEmpty() ? Optional.empty() : Optional.of(validationOptions);
 	}
 
+	/**
+	 * Get the {@link TimeSeriesOptions} if available.
+	 *
+	 * @return {@link Optional#empty()} if not specified.
+	 * @since 3.3
+	 */
+	public Optional<TimeSeriesOptions> getTimeSeriesOptions() {
+		return Optional.ofNullable(timeSeriesOptions);
+	}
+
 	/**
 	 * Encapsulation of ValidationOptions options.
 	 *
@@ -385,7 +428,7 @@ public class CollectionOptions {
 		/**
 		 * Get the {@code validationAction} to perform.
 		 *
-		 * @return @return {@link Optional#empty()} if not set.
+		 * @return {@link Optional#empty()} if not set.
 		 */
 		public Optional<ValidationAction> getValidationAction() {
 			return Optional.ofNullable(validationAction);
@@ -398,4 +441,89 @@ public class CollectionOptions {
 			return !Optionals.isAnyPresent(getValidator(), getValidationAction(), getValidationLevel());
 		}
 	}
+
+	/**
+	 * Options applicable to Time Series collections.
+	 *
+	 * @author Christoph Strobl
+	 * @since 3.3
+	 * @see <a href=
+	 *      "https://docs.mongodb.com/manual/core/timeseries-collections">https://docs.mongodb.com/manual/core/timeseries-collections</a>
+	 */
+	public static class TimeSeriesOptions {
+
+		private final String timeField;
+
+		private @Nullable final String metaField;
+
+		private final GranularityDefinition granularity;
+
+		private TimeSeriesOptions(String timeField, @Nullable String metaField, GranularityDefinition granularity) {
+
+			Assert.hasText(timeField, "Time field must not be empty or null!");
+
+			this.timeField = timeField;
+			this.metaField = metaField;
+			this.granularity = granularity;
+		}
+
+		/**
+		 * Create a new instance of {@link TimeSeriesOptions} using the given field as its {@literal timeField}. The one,
+		 * that contains the date in each time series document. <br />
+		 * {@link Field#name() Annotated fieldnames} will be considered during the mapping process.
+		 *
+		 * @param timeField must not be {@literal null}.
+		 * @return new instance of {@link TimeSeriesOptions}.
+		 */
+		public static TimeSeriesOptions timeSeries(String timeField) {
+			return new TimeSeriesOptions(timeField, null, Granularity.DEFAULT);
+		}
+
+		/**
+		 * Set the name of the field which contains metadata in each time series document. Should not be the {@literal id}
+		 * nor {@link TimeSeriesOptions#timeSeries(String)} timeField} nor point to an {@literal array} or
+		 * {@link java.util.Collection}. <br />
+		 * {@link Field#name() Annotated fieldnames} will be considered during the mapping process.
+		 *
+		 * @param metaField must not be {@literal null}.
+		 * @return new instance of {@link TimeSeriesOptions}.
+		 */
+		public TimeSeriesOptions metaField(String metaField) {
+			return new TimeSeriesOptions(timeField, metaField, granularity);
+		}
+
+		/**
+		 * Select the {@link GranularityDefinition} parameter to define how data in the time series collection is organized.
+		 * Select one that is closest to the time span between incoming measurements.
+		 *
+		 * @return new instance of {@link TimeSeriesOptions}.
+		 * @see Granularity
+		 */
+		public TimeSeriesOptions granularity(GranularityDefinition granularity) {
+			return new TimeSeriesOptions(timeField, metaField, granularity);
+		}
+
+		/**
+		 * @return never {@literal null}.
+		 */
+		public String getTimeField() {
+			return timeField;
+		}
+
+		/**
+		 * @return can be {@literal null}. Might be an {@literal empty} {@link String} as well, so maybe check via
+		 *         {@link org.springframework.util.StringUtils#hasText(String)}.
+		 */
+		@Nullable
+		public String getMetaField() {
+			return metaField;
+		}
+
+		/**
+		 * @return never {@literal null}.
+		 */
+		public GranularityDefinition getGranularity() {
+			return granularity;
+		}
+	}
 }

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

@@ -109,10 +109,6 @@ class DefaultBulkOperations implements BulkOperations {
 		this.defaultWriteConcern = defaultWriteConcern;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#insert(java.lang.Object)
-	 */
 	@Override
 	public BulkOperations insert(Object document) {
 
@@ -125,10 +121,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#insert(java.util.List)
-	 */
 	@Override
 	public BulkOperations insert(List<? extends Object> documents) {
 
@@ -139,10 +131,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#updateOne(org.springframework.data.mongodb.core.query.Query, org.springframework.data.mongodb.core.query.Update)
-	 */
 	@Override
 	@SuppressWarnings("unchecked")
 	public BulkOperations updateOne(Query query, Update update) {
@@ -153,10 +141,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return updateOne(Collections.singletonList(Pair.of(query, update)));
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#updateOne(java.util.List)
-	 */
 	@Override
 	public BulkOperations updateOne(List<Pair<Query, Update>> updates) {
 
@@ -169,10 +153,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#updateMulti(org.springframework.data.mongodb.core.query.Query, org.springframework.data.mongodb.core.query.Update)
-	 */
 	@Override
 	@SuppressWarnings("unchecked")
 	public BulkOperations updateMulti(Query query, Update update) {
@@ -183,10 +163,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return updateMulti(Collections.singletonList(Pair.of(query, update)));
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#updateMulti(java.util.List)
-	 */
 	@Override
 	public BulkOperations updateMulti(List<Pair<Query, Update>> updates) {
 
@@ -199,19 +175,11 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#upsert(org.springframework.data.mongodb.core.query.Query, org.springframework.data.mongodb.core.query.Update)
-	 */
 	@Override
 	public BulkOperations upsert(Query query, Update update) {
 		return update(query, update, true, true);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#upsert(java.util.List)
-	 */
 	@Override
 	public BulkOperations upsert(List<Pair<Query, Update>> updates) {
 
@@ -222,10 +190,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#remove(org.springframework.data.mongodb.core.query.Query)
-	 */
 	@Override
 	public BulkOperations remove(Query query) {
 
@@ -239,10 +203,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#remove(java.util.List)
-	 */
 	@Override
 	public BulkOperations remove(List<Query> removes) {
 
@@ -255,10 +215,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#replaceOne(org.springframework.data.mongodb.core.query.Query, java.lang.Object, org.springframework.data.mongodb.core.FindAndReplaceOptions)
-	 */
 	@Override
 	public BulkOperations replaceOne(Query query, Object replacement, FindAndReplaceOptions options) {
 
@@ -278,10 +234,6 @@ class DefaultBulkOperations implements BulkOperations {
 		return this;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.BulkOperations#executeBulk()
-	 */
 	@Override
 	public com.mongodb.bulk.BulkWriteResult execute() {
 

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

@@ -112,10 +112,6 @@ public class DefaultIndexOperations implements IndexOperations {
 		this.type = type;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.IndexOperations#ensureIndex(org.springframework.data.mongodb.core.index.IndexDefinition)
-	 */
 	public String ensureIndex(final IndexDefinition indexDefinition) {
 
 		return execute(collection -> {
@@ -150,10 +146,6 @@ public class DefaultIndexOperations implements IndexOperations {
 		return null;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.IndexOperations#dropIndex(java.lang.String)
-	 */
 	public void dropIndex(final String name) {
 
 		execute(collection -> {
@@ -163,18 +155,10 @@ public class DefaultIndexOperations implements IndexOperations {
 
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.IndexOperations#dropAllIndexes()
-	 */
 	public void dropAllIndexes() {
 		dropIndex("*");
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.IndexOperations#getIndexInfo()
-	 */
 	public List<IndexInfo> getIndexInfo() {
 
 		return execute(new CollectionCallback<List<IndexInfo>>() {

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

@@ -42,12 +42,8 @@ class DefaultIndexOperationsProvider implements IndexOperationsProvider {
 		this.mapper = mapper;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.IndexOperationsProvider#reactiveIndexOps(java.lang.String)
-	 */
 	@Override
-	public IndexOperations indexOps(String collectionName) {
-		return new DefaultIndexOperations(mongoDbFactory, collectionName, mapper);
+	public IndexOperations indexOps(String collectionName, Class<?> type) {
+		return new DefaultIndexOperations(mongoDbFactory, collectionName, mapper, type);
 	}
 }

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

@@ -86,10 +86,6 @@ public class DefaultReactiveIndexOperations implements ReactiveIndexOperations {
 		this.type = type;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#ensureIndex(org.springframework.data.mongodb.core.index.IndexDefinition)
-	 */
 	public Mono<String> ensureIndex(final IndexDefinition indexDefinition) {
 
 		return mongoOperations.execute(collectionName, collection -> {
@@ -119,26 +115,14 @@ public class DefaultReactiveIndexOperations implements ReactiveIndexOperations {
 				.orElse(null);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#dropIndex(java.lang.String)
-	 */
 	public Mono<Void> dropIndex(final String name) {
 		return mongoOperations.execute(collectionName, collection -> collection.dropIndex(name)).then();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#dropAllIndexes()
-	 */
 	public Mono<Void> dropAllIndexes() {
 		return dropIndex("*");
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.index.ReactiveIndexOperations#getIndexInfo()
-	 */
 	public Flux<IndexInfo> getIndexInfo() {
 
 		return mongoOperations.execute(collectionName, collection -> collection.listIndexes(Document.class)) //

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

@@ -70,19 +70,11 @@ class DefaultScriptOperations implements ScriptOperations {
 		this.mongoOperations = mongoOperations;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#register(org.springframework.data.mongodb.core.script.ExecutableMongoScript)
-	 */
 	@Override
 	public NamedMongoScript register(ExecutableMongoScript script) {
 		return register(new NamedMongoScript(generateScriptName(), script));
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#register(org.springframework.data.mongodb.core.script.NamedMongoScript)
-	 */
 	@Override
 	public NamedMongoScript register(NamedMongoScript script) {
 
@@ -92,10 +84,6 @@ class DefaultScriptOperations implements ScriptOperations {
 		return script;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#execute(org.springframework.data.mongodb.core.script.ExecutableMongoScript, java.lang.Object[])
-	 */
 	@Override
 	public Object execute(final ExecutableMongoScript script, final Object... args) {
 
@@ -115,10 +103,6 @@ class DefaultScriptOperations implements ScriptOperations {
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#call(java.lang.String, java.lang.Object[])
-	 */
 	@Override
 	public Object call(final String scriptName, final Object... args) {
 
@@ -135,10 +119,6 @@ class DefaultScriptOperations implements ScriptOperations {
 		});
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#exists(java.lang.String)
-	 */
 	@Override
 	public boolean exists(String scriptName) {
 
@@ -147,10 +127,6 @@ class DefaultScriptOperations implements ScriptOperations {
 		return mongoOperations.exists(query(where("_id").is(scriptName)), NamedMongoScript.class, SCRIPT_COLLECTION_NAME);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ScriptOperations#getScriptNames()
-	 */
 	@Override
 	public Set<String> getScriptNames() {
 

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2021 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;
+
+/**
+ * Encryption algorithms supported by MongoDB Client Side Field Level Encryption.
+ *
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+public final class EncryptionAlgorithms {
+
+	public static final String AEAD_AES_256_CBC_HMAC_SHA_512_Deterministic = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic";
+	public static final String AEAD_AES_256_CBC_HMAC_SHA_512_Random = "AEAD_AES_256_CBC_HMAC_SHA_512-Random";
+
+}

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

@@ -16,30 +16,41 @@
 package org.springframework.data.mongodb.core;
 
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Optional;
 
 import org.bson.Document;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
+import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.mapping.IdentifierAccessor;
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
+import org.springframework.data.mongodb.core.CollectionOptions.TimeSeriesOptions;
+import org.springframework.data.mongodb.core.convert.MongoConverter;
 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.mapping.TimeSeries;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.data.mongodb.core.timeseries.Granularity;
+import org.springframework.data.projection.EntityProjection;
+import org.springframework.data.projection.EntityProjectionIntrospector;
+import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * Common operations performed on an entity in the context of it's mapping metadata.
@@ -57,8 +68,19 @@ class EntityOperations {
 
 	private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context;
 
-	EntityOperations(MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context) {
+	private final EntityProjectionIntrospector introspector;
+
+	EntityOperations(MongoConverter converter) {
+		this(converter.getMappingContext(), converter.getCustomConversions(), converter.getProjectionFactory());
+	}
+
+	EntityOperations(MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context,
+			CustomConversions conversions, ProjectionFactory projectionFactory) {
 		this.context = context;
+		this.introspector = EntityProjectionIntrospector.create(projectionFactory,
+				EntityProjectionIntrospector.ProjectionPredicate.typeHierarchy()
+						.and(((target, underlyingType) -> !conversions.isSimpleType(target))),
+				context);
 	}
 
 	/**
@@ -107,6 +129,20 @@ class EntityOperations {
 		return AdaptibleMappedEntity.of(entity, context, conversionService);
 	}
 
+	/**
+	 * @param source can be {@literal null}.
+	 * @return {@literal true} if the given value is an {@literal array}, {@link Collection} or {@link Iterator}.
+	 * @since 3.2
+	 */
+	static boolean isCollectionLike(@Nullable Object source) {
+
+		if (source == null) {
+			return false;
+		}
+
+		return ObjectUtils.isArray(source) || source instanceof Collection || source instanceof Iterator;
+	}
+
 	/**
 	 * @param entityClass should not be null.
 	 * @return the {@link MongoPersistentEntity#getCollection() collection name}.
@@ -209,6 +245,20 @@ class EntityOperations {
 		return UntypedOperations.instance();
 	}
 
+	/**
+	 * Introspect the given {@link Class result type} in the context of the {@link Class entity type} whether the returned
+	 * type is a projection and what property paths are participating in the projection.
+	 *
+	 * @param resultType the type to project on. Must not be {@literal null}.
+	 * @param entityType the source domain type. Must not be {@literal null}.
+	 * @return the introspection result.
+	 * @since 3.4
+	 * @see EntityProjectionIntrospector#introspect(Class, Class)
+	 */
+	public <M, D> EntityProjection<M, D> introspectProjection(Class<M> resultType, Class<D> entityType) {
+		return introspector.introspect(resultType, entityType);
+	}
+
 	/**
 	 * A representation of information about an entity.
 	 *
@@ -353,37 +403,21 @@ class EntityOperations {
 			this.map = 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) {
@@ -393,19 +427,11 @@ class EntityOperations {
 			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 //
@@ -413,47 +439,27 @@ class EntityOperations {
 					: 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;
@@ -466,10 +472,6 @@ class EntityOperations {
 			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) {
@@ -509,28 +511,16 @@ class EntityOperations {
 			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() {
 
@@ -543,10 +533,6 @@ class EntityOperations {
 			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() {
 
@@ -557,10 +543,6 @@ class EntityOperations {
 					.and(versionProperty.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) {
 
@@ -576,10 +558,6 @@ class EntityOperations {
 			return MappedDocument.of(document);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.Entity#assertUpdateableIdIfNotSet()
-		 */
 		public void assertUpdateableIdIfNotSet() {
 
 			if (!entity.hasIdProperty()) {
@@ -600,38 +578,22 @@ class EntityOperations {
 			}
 		}
 
-		/*
-		 * (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());
@@ -666,10 +628,6 @@ class EntityOperations {
 					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) {
@@ -691,10 +649,6 @@ class EntityOperations {
 			return propertyAccessor.getBean();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.MappedEntity#getVersion()
-		 */
 		@Override
 		@Nullable
 		public Number getVersion() {
@@ -704,10 +658,6 @@ class EntityOperations {
 			return propertyAccessor.getProperty(versionProperty, Number.class);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity#initializeVersionProperty()
-		 */
 		@Override
 		public T initializeVersionProperty() {
 
@@ -722,10 +672,6 @@ class EntityOperations {
 			return propertyAccessor.getBean();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity#incrementVersion()
-		 */
 		@Override
 		public T incrementVersion() {
 
@@ -762,6 +708,24 @@ class EntityOperations {
 		 * @return
 		 */
 		Optional<Collation> getCollation(Query query);
+
+		/**
+		 * Derive the applicable {@link CollectionOptions} for the given type.
+		 *
+		 * @return never {@literal null}.
+		 * @since 3.3
+		 */
+		CollectionOptions getCollectionOptions();
+
+		/**
+		 * Map the fields of a given {@link TimeSeriesOptions} against the target domain type to consider potentially
+		 * annotated field names.
+		 *
+		 * @param options must not be {@literal null}.
+		 * @return never {@literal null}.
+		 * @since 3.3
+		 */
+		TimeSeriesOptions mapTimeSeriesOptions(TimeSeriesOptions options);
 	}
 
 	/**
@@ -779,19 +743,11 @@ class EntityOperations {
 			return (TypedOperations) INSTANCE;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation()
-		 */
 		@Override
 		public Optional<Collation> getCollation() {
 			return Optional.empty();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public Optional<Collation> getCollation(Query query) {
 
@@ -801,6 +757,16 @@ class EntityOperations {
 
 			return query.getCollation();
 		}
+
+		@Override
+		public CollectionOptions getCollectionOptions() {
+			return CollectionOptions.empty();
+		}
+
+		@Override
+		public TimeSeriesOptions mapTimeSeriesOptions(TimeSeriesOptions options) {
+			return options;
+		}
 	}
 
 	/**
@@ -816,19 +782,11 @@ class EntityOperations {
 			this.entity = entity;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation()
-		 */
 		@Override
 		public Optional<Collation> getCollation() {
 			return Optional.ofNullable(entity.getCollation());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.EntityOperations.TypedOperations#getCollation(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public Optional<Collation> getCollation(Query query) {
 
@@ -838,6 +796,58 @@ class EntityOperations {
 
 			return Optional.ofNullable(entity.getCollation());
 		}
+
+		@Override
+		public CollectionOptions getCollectionOptions() {
+
+			CollectionOptions collectionOptions = CollectionOptions.empty();
+			if (entity.hasCollation()) {
+				collectionOptions = collectionOptions.collation(entity.getCollation());
+			}
+
+			if (entity.isAnnotationPresent(TimeSeries.class)) {
+
+				TimeSeries timeSeries = entity.getRequiredAnnotation(TimeSeries.class);
+
+				if (entity.getPersistentProperty(timeSeries.timeField()) == null) {
+					throw new MappingException(String.format("Time series field '%s' does not exist in type %s",
+							timeSeries.timeField(), entity.getName()));
+				}
+
+				TimeSeriesOptions options = TimeSeriesOptions.timeSeries(timeSeries.timeField());
+				if (StringUtils.hasText(timeSeries.metaField())) {
+
+					if (entity.getPersistentProperty(timeSeries.metaField()) == null) {
+						throw new MappingException(
+								String.format("Meta field '%s' does not exist in type %s", timeSeries.metaField(), entity.getName()));
+					}
+
+					options = options.metaField(timeSeries.metaField());
+				}
+				if (!Granularity.DEFAULT.equals(timeSeries.granularity())) {
+					options = options.granularity(timeSeries.granularity());
+				}
+				collectionOptions = collectionOptions.timeSeries(options);
+			}
+
+			return collectionOptions;
+		}
+
+		@Override
+		public TimeSeriesOptions mapTimeSeriesOptions(TimeSeriesOptions source) {
+
+			TimeSeriesOptions target = TimeSeriesOptions.timeSeries(mappedNameOrDefault(source.getTimeField()));
+
+			if (StringUtils.hasText(source.getMetaField())) {
+				target = target.metaField(mappedNameOrDefault(source.getMetaField()));
+			}
+			return target.granularity(source.getGranularity());
+		}
+
+		private String mappedNameOrDefault(String name) {
+			MongoPersistentProperty persistentProperty = entity.getPersistentProperty(name);
+			return persistentProperty != null ? persistentProperty.getFieldName() : name;
+		}
 	}
 
 }

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

@@ -37,10 +37,6 @@ class ExecutableAggregationOperationSupport implements ExecutableAggregationOper
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ExecutableAggregationOperation#aggregateAndReturn(java.lang.Class)
-	 */
 	@Override
 	public <T> ExecutableAggregation<T> aggregateAndReturn(Class<T> domainType) {
 
@@ -69,10 +65,6 @@ class ExecutableAggregationOperationSupport implements ExecutableAggregationOper
 			this.collection = collection;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableAggregationOperation.AggregationWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public AggregationWithAggregation<T> inCollection(String collection) {
 
@@ -81,10 +73,6 @@ class ExecutableAggregationOperationSupport implements ExecutableAggregationOper
 			return new ExecutableAggregationSupport<>(template, domainType, aggregation, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableAggregationOperation.AggregationWithAggregation#by(org.springframework.data.mongodb.core.aggregation.Aggregation)
-		 */
 		@Override
 		public TerminatingAggregation<T> by(Aggregation aggregation) {
 
@@ -93,19 +81,11 @@ class ExecutableAggregationOperationSupport implements ExecutableAggregationOper
 			return new ExecutableAggregationSupport<>(template, domainType, aggregation, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableAggregationOperation.TerminatingAggregation#all()
-		 */
 		@Override
 		public AggregationResults<T> all() {
 			return template.aggregate(aggregation, getCollectionName(aggregation), domainType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableAggregationOperation.TerminatingAggregation#stream()
-		 */
 		@Override
 		public CloseableIterator<T> stream() {
 			return template.aggregateStream(aggregation, getCollectionName(aggregation), domainType);

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

@@ -125,6 +125,11 @@ public interface ExecutableFindOperation {
 
 		/**
 		 * Get the number of matching elements.
+		 * <br />
+		 * This method uses an {@link com.mongodb.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions) aggregation
+		 * execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees shard,
+		 * session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+		 * {@link MongoOperations#estimatedCount(String)} for empty queries instead.
 		 *
 		 * @return total number of matching elements.
 		 */

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

@@ -51,10 +51,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ExecutableFindOperation#query(java.lang.Class)
-	 */
 	@Override
 	public <T> ExecutableFind<T> query(Class<T> domainType) {
 
@@ -86,10 +82,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			this.query = query;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.FindWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public FindWithProjection<T> inCollection(String collection) {
 
@@ -98,10 +90,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return new ExecutableFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.FindWithProjection#as(Class)
-		 */
 		@Override
 		public <T1> FindWithQuery<T1> as(Class<T1> returnType) {
 
@@ -110,10 +98,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return new ExecutableFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.FindWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public TerminatingFind<T> matching(Query query) {
 
@@ -122,10 +106,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return new ExecutableFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#oneValue()
-		 */
 		@Override
 		public T oneValue() {
 
@@ -142,10 +122,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return result.iterator().next();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#firstValue()
-		 */
 		@Override
 		public T firstValue() {
 
@@ -154,55 +130,31 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			return ObjectUtils.isEmpty(result) ? null : result.iterator().next();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#all()
-		 */
 		@Override
 		public List<T> all() {
 			return doFind(null);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#stream()
-		 */
 		@Override
 		public Stream<T> stream() {
 			return StreamUtils.createStreamFromIterator(doStream());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.FindWithQuery#near(org.springframework.data.mongodb.core.query.NearQuery)
-		 */
 		@Override
 		public TerminatingFindNear<T> near(NearQuery nearQuery) {
 			return () -> template.geoNear(nearQuery, domainType, getCollectionName(), returnType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#count()
-		 */
 		@Override
 		public long count() {
 			return template.count(query, domainType, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFind#exists()
-		 */
 		@Override
 		public boolean exists() {
 			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) {
@@ -257,10 +209,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			this.delegate = delegate;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.CursorPreparer#prepare(com.mongodb.clientFindIterable)
-		 */
 		@Override
 		public FindIterable<Document> prepare(FindIterable<Document> iterable) {
 
@@ -295,10 +243,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			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) {
@@ -308,10 +252,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			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) {
 
@@ -320,10 +260,6 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			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/ExecutableInsertOperationSupport.java

@@ -40,10 +40,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.coreExecutableInsertOperation#insert(java.lan.Class)
-	 */
 	@Override
 	public <T> ExecutableInsert<T> insert(Class<T> domainType) {
 
@@ -71,10 +67,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 			this.bulkMode = bulkMode;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.TerminatingInsert#insert(java.lang.Class)
-		 */
 		@Override
 		public T one(T object) {
 
@@ -83,10 +75,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 			return template.insert(object, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.TerminatingInsert#all(java.util.Collection)
-		 */
 		@Override
 		public Collection<T> all(Collection<? extends T> objects) {
 
@@ -95,10 +83,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 			return template.insert(objects, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.TerminatingBulkInsert#bulk(java.util.Collection)
-		 */
 		@Override
 		public BulkWriteResult bulk(Collection<? extends T> objects) {
 
@@ -108,10 +92,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 					.insert(new ArrayList<>(objects)).execute();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.InsertWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public InsertWithBulkMode<T> inCollection(String collection) {
 
@@ -120,10 +100,6 @@ class ExecutableInsertOperationSupport implements ExecutableInsertOperation {
 			return new ExecutableInsertSupport<>(template, domainType, collection, bulkMode);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableInsertOperation.InsertWithBulkMode#withBulkMode(org.springframework.data.mongodb.core.BulkMode)
-		 */
 		@Override
 		public TerminatingBulkInsert<T> withBulkMode(BulkMode bulkMode) {
 

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

@@ -41,10 +41,6 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 		this.tempate = tempate;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation#remove(java.lang.Class)
-	 */
 	@Override
 	public <T> ExecutableRemove<T> remove(Class<T> domainType) {
 
@@ -71,10 +67,6 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 			this.collection = collection;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.RemoveWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public RemoveWithQuery<T> inCollection(String collection) {
 
@@ -83,10 +75,6 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 			return new ExecutableRemoveSupport<>(template, domainType, query, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.RemoveWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public TerminatingRemove<T> matching(Query query) {
 
@@ -95,28 +83,16 @@ class ExecutableRemoveOperationSupport implements ExecutableRemoveOperation {
 			return new ExecutableRemoveSupport<>(template, domainType, query, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.TerminatingRemove#all()
-		 */
 		@Override
 		public DeleteResult all() {
 			return template.doRemove(getCollectionName(), query, domainType, true);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.TerminatingRemove#one()
-		 */
 		@Override
 		public DeleteResult one() {
 			return template.doRemove(getCollectionName(), query, domainType, false);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableRemoveOperation.TerminatingRemove#findAndRemove()
-		 */
 		@Override
 		public List<T> findAndRemove() {
 

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

@@ -89,7 +89,7 @@ public interface ExecutableUpdateOperation {
 
 	/**
 	 * Trigger
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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

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

@@ -40,10 +40,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation#update(java.lang.Class)
-	 */
 	@Override
 	public <T> ExecutableUpdate<T> update(Class<T> domainType) {
 
@@ -85,10 +81,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 			this.targetType = targetType;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithUpdate#apply(org.springframework.data.mongodb.core.query.UpdateDefinition)
-		 */
 		@Override
 		public TerminatingUpdate<T> apply(UpdateDefinition update) {
 
@@ -98,10 +90,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public UpdateWithQuery<T> inCollection(String collection) {
 
@@ -111,10 +99,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.FindAndModifyWithOptions#withOptions(org.springframework.data.mongodb.core.FindAndModifyOptions)
-		 */
 		@Override
 		public TerminatingFindAndModify<T> withOptions(FindAndModifyOptions options) {
 
@@ -124,10 +108,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.UpdateWithUpdate#replaceWith(Object)
-		 */
 		@Override
 		public FindAndReplaceWithProjection<T> replaceWith(T replacement) {
 
@@ -137,10 +117,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					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) {
 
@@ -150,10 +126,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					options, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public UpdateWithUpdate<T> matching(Query query) {
 
@@ -163,10 +135,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					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) {
 
@@ -176,37 +144,21 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					findAndReplaceOptions, replacement, resultType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingUpdate#all()
-		 */
 		@Override
 		public UpdateResult all() {
 			return doUpdate(true, false);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingUpdate#first()
-		 */
 		@Override
 		public UpdateResult first() {
 			return doUpdate(false, false);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingUpdate#upsert()
-		 */
 		@Override
 		public UpdateResult upsert() {
 			return doUpdate(true, true);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingFindAndModify#findAndModifyValue()
-		 */
 		@Override
 		public @Nullable T findAndModifyValue() {
 
@@ -215,10 +167,6 @@ class ExecutableUpdateOperationSupport implements ExecutableUpdateOperation {
 					getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ExecutableUpdateOperation.TerminatingFindAndReplace#findAndReplaceValue()
-		 */
 		@Override
 		public @Nullable T findAndReplaceValue() {
 

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

@@ -17,7 +17,7 @@ package org.springframework.data.mongodb.core;
 
 /**
  * Options for
- * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>.
+ * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace</a>.
  * <br />
  * Defaults to
  * <dl>

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

@@ -115,6 +115,10 @@ abstract class IndexConverters {
 				ops = ops.collation(fromDocument(indexOptions.get("collation", Document.class)));
 			}
 
+			if (indexOptions.containsKey("wildcardProjection")) {
+				ops.wildcardProjection(indexOptions.get("wildcardProjection", Document.class));
+			}
+
 			return ops;
 		};
 	}

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

@@ -112,49 +112,34 @@ public class MappedDocument {
 			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();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.query.UpdateDefinition#getArrayFilters()
-		 */
 		@Override
 		public List<ArrayFilter> getArrayFilters() {
 			return delegate.getArrayFilters();
 		}
+
+		@Override
+		public boolean hasArrayFilters() {
+			return delegate.hasArrayFilters();
+		}
 	}
 }

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

@@ -20,13 +20,20 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+
+import org.bson.Document;
 
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.ArrayJsonSchemaProperty;
+import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.EncryptedJsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.ObjectJsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.JsonSchemaObject;
 import org.springframework.data.mongodb.core.schema.JsonSchemaObject.Type;
@@ -34,10 +41,12 @@ import org.springframework.data.mongodb.core.schema.JsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema.MongoJsonSchemaBuilder;
 import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject;
+import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link MongoJsonSchemaCreator} implementation using both {@link MongoConverter} and {@link MappingContext} to obtain
@@ -52,6 +61,7 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 	private final MongoConverter converter;
 	private final MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	private final Predicate<JsonSchemaPropertyContext> filter;
 
 	/**
 	 * Create a new instance of {@link MappingMongoJsonSchemaCreator}.
@@ -61,27 +71,55 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 	@SuppressWarnings("unchecked")
 	MappingMongoJsonSchemaCreator(MongoConverter converter) {
 
-		Assert.notNull(converter, "Converter must not be null!");
-		this.converter = converter;
-		this.mappingContext = (MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty>) converter
-				.getMappingContext();
+		this(converter, (MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty>) converter.getMappingContext(),
+				(property) -> true);
+	}
+
+	@SuppressWarnings("unchecked")
+	MappingMongoJsonSchemaCreator(MongoConverter converter,
+			MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext,
+			Predicate<JsonSchemaPropertyContext> filter) {
+
+		Assert.notNull(converter, "Converter must not be null!");
+		this.converter = converter;
+		this.mappingContext = mappingContext;
+		this.filter = filter;
+	}
+
+	@Override
+	public MongoJsonSchemaCreator filter(Predicate<JsonSchemaPropertyContext> filter) {
+		return new MappingMongoJsonSchemaCreator(converter, mappingContext, filter);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * org.springframework.data.mongodb.core.MongoJsonSchemaCreator#createSchemaFor(java.lang.Class)
-	 */
 	@Override
 	public MongoJsonSchema createSchemaFor(Class<?> type) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getRequiredPersistentEntity(type);
 		MongoJsonSchemaBuilder schemaBuilder = MongoJsonSchema.builder();
 
+		{
+			Encrypted encrypted = entity.findAnnotation(Encrypted.class);
+			if (encrypted != null) {
+
+				Document encryptionMetadata = new Document();
+
+				Collection<Object> encryptionKeyIds = entity.getEncryptionKeyIds();
+				if (!CollectionUtils.isEmpty(encryptionKeyIds)) {
+					encryptionMetadata.append("keyId", encryptionKeyIds);
+				}
+
+				if (StringUtils.hasText(encrypted.algorithm())) {
+					encryptionMetadata.append("algorithm", encrypted.algorithm());
+				}
+
+				schemaBuilder.encryptionMetadata(encryptionMetadata);
+			}
+		}
+
 		List<JsonSchemaProperty> schemaProperties = computePropertiesForEntity(Collections.emptyList(), entity);
 		schemaBuilder.properties(schemaProperties.toArray(new JsonSchemaProperty[0]));
 
 		return schemaBuilder.build();
-
 	}
 
 	private List<JsonSchemaProperty> computePropertiesForEntity(List<MongoPersistentProperty> path,
@@ -93,6 +131,11 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 			List<MongoPersistentProperty> currentPath = new ArrayList<>(path);
 
+			if (!filter.test(new PropertyContext(
+					currentPath.stream().map(PersistentProperty::getName).collect(Collectors.joining(".")), nested))) {
+				continue;
+			}
+
 			if (path.contains(nested)) { // cycle guard
 				schemaProperties.add(createSchemaProperty(computePropertyFieldName(CollectionUtils.lastElement(currentPath)),
 						Object.class, false));
@@ -114,21 +157,88 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 		Class<?> rawTargetType = computeTargetType(property); // target type before conversion
 		Class<?> targetType = converter.getTypeMapper().getWriteTargetTypeFor(rawTargetType); // conversion target type
 
-		if (property.isEntity() && ObjectUtils.nullSafeEquals(rawTargetType, targetType)) {
+		if (!isCollection(property) && property.isEntity() && ObjectUtils.nullSafeEquals(rawTargetType, targetType)) {
 			return createObjectSchemaPropertyForEntity(path, property, required);
 		}
 
 		String fieldName = computePropertyFieldName(property);
 
-		if (property.isCollectionLike()) {
-			return createSchemaProperty(fieldName, targetType, required);
+		JsonSchemaProperty schemaProperty;
+		if (isCollection(property)) {
+			schemaProperty = createArraySchemaProperty(fieldName, property, required);
 		} else if (property.isMap()) {
-			return createSchemaProperty(fieldName, Type.objectType(), required);
+			schemaProperty = createSchemaProperty(fieldName, Type.objectType(), required);
 		} else if (ClassUtils.isAssignable(Enum.class, targetType)) {
-			return createEnumSchemaProperty(fieldName, targetType, required);
+			schemaProperty = createEnumSchemaProperty(fieldName, targetType, required);
+		} else {
+			schemaProperty = createSchemaProperty(fieldName, targetType, required);
 		}
 
-		return createSchemaProperty(fieldName, targetType, required);
+		return applyEncryptionDataIfNecessary(property, schemaProperty);
+	}
+
+	private JsonSchemaProperty createArraySchemaProperty(String fieldName, MongoPersistentProperty property,
+			boolean required) {
+
+		ArrayJsonSchemaProperty schemaProperty = JsonSchemaProperty.array(fieldName);
+
+		if (isSpecificType(property)) {
+			schemaProperty = potentiallyEnhanceArraySchemaProperty(property, schemaProperty);
+		}
+
+		return createPotentiallyRequiredSchemaProperty(schemaProperty, required);
+	}
+
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	private ArrayJsonSchemaProperty potentiallyEnhanceArraySchemaProperty(MongoPersistentProperty property,
+			ArrayJsonSchemaProperty schemaProperty) {
+
+		MongoPersistentEntity<?> persistentEntity = mappingContext
+				.getPersistentEntity(property.getTypeInformation().getRequiredComponentType());
+
+		if (persistentEntity != null) {
+
+			List<JsonSchemaProperty> nestedProperties = computePropertiesForEntity(Collections.emptyList(), persistentEntity);
+
+			if (nestedProperties.isEmpty()) {
+				return schemaProperty;
+			}
+
+			return schemaProperty
+					.items(JsonSchemaObject.object().properties(nestedProperties.toArray(new JsonSchemaProperty[0])));
+		}
+
+		if (ClassUtils.isAssignable(Enum.class, property.getActualType())) {
+
+			List<Object> possibleValues = getPossibleEnumValues((Class<Enum>) property.getActualType());
+
+			return schemaProperty
+					.items(createSchemaObject(computeTargetType(property.getActualType(), possibleValues), possibleValues));
+		}
+
+		return schemaProperty.items(JsonSchemaObject.of(property.getActualType()));
+	}
+
+	private boolean isSpecificType(MongoPersistentProperty property) {
+		return !ClassTypeInformation.OBJECT.equals(property.getTypeInformation().getActualType());
+	}
+
+	private JsonSchemaProperty applyEncryptionDataIfNecessary(MongoPersistentProperty property,
+			JsonSchemaProperty schemaProperty) {
+
+		Encrypted encrypted = property.findAnnotation(Encrypted.class);
+		if (encrypted == null) {
+			return schemaProperty;
+		}
+
+		EncryptedJsonSchemaProperty enc = new EncryptedJsonSchemaProperty(schemaProperty);
+		if (StringUtils.hasText(encrypted.algorithm())) {
+			enc = enc.algorithm(encrypted.algorithm());
+		}
+		if (!ObjectUtils.isEmpty(encrypted.keyId())) {
+			enc = enc.keys(property.getEncryptionKeyIds());
+		}
+		return enc;
 	}
 
 	private JsonSchemaProperty createObjectSchemaPropertyForEntity(List<MongoPersistentProperty> path,
@@ -142,15 +252,12 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 				target.properties(nestedProperties.toArray(new JsonSchemaProperty[0])), required);
 	}
 
+	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private JsonSchemaProperty createEnumSchemaProperty(String fieldName, Class<?> targetType, boolean required) {
 
-		List<Object> possibleValues = new ArrayList<>();
+		List<Object> possibleValues = getPossibleEnumValues((Class<Enum>) targetType);
 
-		for (Object enumValue : EnumSet.allOf((Class) targetType)) {
-			possibleValues.add(converter.convertToMongoType(enumValue));
-		}
-
-		targetType = possibleValues.isEmpty() ? targetType : possibleValues.iterator().next().getClass();
+		targetType = computeTargetType(targetType, possibleValues);
 		return createSchemaProperty(fieldName, targetType, required, possibleValues);
 	}
 
@@ -161,14 +268,20 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 	JsonSchemaProperty createSchemaProperty(String fieldName, Object type, boolean required,
 			Collection<?> possibleValues) {
 
+		TypedJsonSchemaObject schemaObject = createSchemaObject(type, possibleValues);
+
+		return createPotentiallyRequiredSchemaProperty(JsonSchemaProperty.named(fieldName).with(schemaObject), required);
+	}
+
+	private TypedJsonSchemaObject createSchemaObject(Object type, Collection<?> possibleValues) {
+
 		TypedJsonSchemaObject schemaObject = type instanceof Type ? JsonSchemaObject.of(Type.class.cast(type))
 				: JsonSchemaObject.of(Class.class.cast(type));
 
 		if (!CollectionUtils.isEmpty(possibleValues)) {
 			schemaObject = schemaObject.possibleValues(possibleValues);
 		}
-
-		return createPotentiallyRequiredSchemaProperty(JsonSchemaProperty.named(fieldName).with(schemaObject), required);
+		return schemaObject;
 	}
 
 	private String computePropertyFieldName(PersistentProperty property) {
@@ -199,12 +312,53 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 		return mongoProperty.getFieldType() != mongoProperty.getActualType() ? Object.class : mongoProperty.getFieldType();
 	}
 
-	static JsonSchemaProperty createPotentiallyRequiredSchemaProperty(JsonSchemaProperty property, boolean required) {
+	private static Class<?> computeTargetType(Class<?> fallback, List<Object> possibleValues) {
+		return possibleValues.isEmpty() ? fallback : possibleValues.iterator().next().getClass();
+	}
 
-		if (!required) {
+	private <E extends Enum<E>> List<Object> getPossibleEnumValues(Class<E> targetType) {
+
+		EnumSet<E> enumSet = EnumSet.allOf(targetType);
+		List<Object> possibleValues = new ArrayList<>(enumSet.size());
+
+		for (Object enumValue : enumSet) {
+			possibleValues.add(converter.convertToMongoType(enumValue));
+		}
+
+		return possibleValues;
+	}
+
+	private static boolean isCollection(MongoPersistentProperty property) {
+		return property.isCollectionLike() && !property.getType().equals(byte[].class);
+	}
+
+	static JsonSchemaProperty createPotentiallyRequiredSchemaProperty(JsonSchemaProperty property, boolean required) {
+		return required ? JsonSchemaProperty.required(property) : property;
+	}
+
+	class PropertyContext implements JsonSchemaPropertyContext {
+
+		private final String path;
+		private final MongoPersistentProperty property;
+
+		public PropertyContext(String path, MongoPersistentProperty property) {
+			this.path = path;
+			this.property = property;
+		}
+
+		@Override
+		public String getPath() {
+			return path;
+		}
+
+		@Override
+		public MongoPersistentProperty getProperty() {
 			return property;
 		}
 
-		return JsonSchemaProperty.required(property);
+		@Override
+		public <T> MongoPersistentEntity<T> resolveEntity(MongoPersistentProperty property) {
+			return (MongoPersistentEntity<T>) mappingContext.getPersistentEntity(property);
+		}
 	}
 }

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

@@ -46,25 +46,16 @@ public class MongoAdmin implements MongoAdminOperations {
 		this.mongoClient = client;
 	}
 
-	/* (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.core.MongoAdminOperations#dropDatabase(java.lang.String)
-	 */
 	@ManagedOperation
 	public void dropDatabase(String databaseName) {
 		getDB(databaseName).drop();
 	}
 
-	/* (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.core.MongoAdminOperations#createDatabase(java.lang.String)
-	 */
 	@ManagedOperation
 	public void createDatabase(String databaseName) {
 		getDB(databaseName);
 	}
 
-	/* (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.core.MongoAdminOperations#getDatabaseStats(java.lang.String)
-	 */
 	@ManagedOperation
 	public String getDatabaseStats(String databaseName) {
 		return getDB(databaseName).runCommand(new Document("dbStats", 1).append("scale", 1024)).toJson();

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

@@ -119,27 +119,15 @@ public class MongoClientFactoryBean extends AbstractFactoryBean<MongoClient> imp
 		this.exceptionTranslator = exceptionTranslator == null ? DEFAULT_EXCEPTION_TRANSLATOR : exceptionTranslator;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.FactoryBean#getObjectType()
-	 */
 	public Class<? extends MongoClient> getObjectType() {
 		return MongoClient.class;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.dao.support.PersistenceExceptionTranslator#translateExceptionIfPossible(java.lang.RuntimeException)
-	 */
 	@Nullable
 	public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
 		return exceptionTranslator.translateExceptionIfPossible(ex);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.config.AbstractFactoryBean#createInstance()
-	 */
 	@Override
 	protected MongoClient createInstance() throws Exception {
 		return createMongoClient(computeClientSetting());
@@ -336,10 +324,6 @@ public class MongoClientFactoryBean extends AbstractFactoryBean<MongoClient> imp
 		return !fromConnectionStringIsDefault ? fromConnectionString : defaultValue;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.beans.factory.config.AbstractFactoryBean#destroyInstance(java.lang.Object)
-	 */
 	@Override
 	protected void destroyInstance(@Nullable MongoClient instance) throws Exception {
 

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

@@ -36,6 +36,7 @@ import com.mongodb.MongoClientSettings.Builder;
 import com.mongodb.ReadConcern;
 import com.mongodb.ReadPreference;
 import com.mongodb.ServerAddress;
+import com.mongodb.ServerApi;
 import com.mongodb.WriteConcern;
 import com.mongodb.connection.ClusterConnectionMode;
 import com.mongodb.connection.ClusterType;
@@ -113,6 +114,7 @@ public class MongoClientSettingsFactoryBean extends AbstractFactoryBean<MongoCli
 	// encryption and retry
 
 	private @Nullable AutoEncryptionSettings autoEncryptionSettings;
+	private @Nullable ServerApi serverApi;
 
 	/**
 	 * @param socketConnectTimeoutMS in msec
@@ -395,6 +397,15 @@ public class MongoClientSettingsFactoryBean extends AbstractFactoryBean<MongoCli
 		this.autoEncryptionSettings = autoEncryptionSettings;
 	}
 
+	/**
+	 * @param serverApi can be {@literal null}.
+	 * @see MongoClientSettings.Builder#serverApi(ServerApi)
+	 * @since 3.3
+	 */
+	public void setServerApi(@Nullable ServerApi serverApi) {
+		this.serverApi = serverApi;
+	}
+
 	@Override
 	public Class<?> getObjectType() {
 		return MongoClientSettings.class;
@@ -476,9 +487,11 @@ public class MongoClientSettingsFactoryBean extends AbstractFactoryBean<MongoCli
 		if (retryWrites != null) {
 			builder = builder.retryWrites(retryWrites);
 		}
-
 		if (uUidRepresentation != null) {
-			builder.uuidRepresentation(uUidRepresentation);
+			builder = builder.uuidRepresentation(uUidRepresentation);
+		}
+		if (serverApi != null) {
+			builder = builder.serverApi(serverApi);
 		}
 
 		return builder.build();

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

@@ -33,7 +33,7 @@ import com.mongodb.client.MongoDatabase;
 /**
  * Common base class for usage with both {@link com.mongodb.client.MongoClients} defining common properties such as
  * database name and exception translator.
- * <p/>
+ * <br />
  * Not intended to be used directly.
  *
  * @author Christoph Strobl
@@ -84,18 +84,10 @@ public abstract class MongoDatabaseFactorySupport<C> implements MongoDatabaseFac
 		this.writeConcern = writeConcern;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.MongoDbFactory#getMongoDatabase()
-	 */
 	public MongoDatabase getMongoDatabase() throws DataAccessException {
 		return getMongoDatabase(getDefaultDatabaseName());
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.MongoDbFactory#getMongoDatabase(java.lang.String)
-	 */
 	@Override
 	public MongoDatabase getMongoDatabase(String dbName) throws DataAccessException {
 
@@ -118,28 +110,16 @@ public abstract class MongoDatabaseFactorySupport<C> implements MongoDatabaseFac
 	 */
 	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 MongoDatabaseFactory withSession(ClientSession session) {
 		return new MongoDatabaseFactorySupport.ClientSessionBoundMongoDbFactory(session, this);
 	}
@@ -180,55 +160,31 @@ public abstract class MongoDatabaseFactorySupport<C> implements MongoDatabaseFac
 			this.delegate = delegate;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.MongoDbFactory#getMongoDatabase()
-		 */
 		@Override
 		public MongoDatabase getMongoDatabase() throws DataAccessException {
 			return proxyMongoDatabase(delegate.getMongoDatabase());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.MongoDbFactory#getMongoDatabase(java.lang.String)
-		 */
 		@Override
 		public MongoDatabase getMongoDatabase(String dbName) throws DataAccessException {
 			return proxyMongoDatabase(delegate.getMongoDatabase(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#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 MongoDatabaseFactory 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();

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

@@ -20,7 +20,7 @@ import org.springframework.dao.support.PersistenceExceptionTranslator;
 /**
  * Common base class for usage with both {@link com.mongodb.client.MongoClients} defining common properties such as
  * database name and exception translator.
- * <p/>
+ * <br />
  * Not intended to be used directly.
  *
  * @author Christoph Strobl

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

@@ -88,10 +88,6 @@ public class MongoEncryptionSettingsFactoryBean implements FactoryBean<AutoEncry
 		this.schemaMap = schemaMap;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see  org.springframework.beans.factory.FactoryBean#getObject()
-	 */
 	@Override
 	public AutoEncryptionSettings getObject() {
 
@@ -109,10 +105,6 @@ public class MongoEncryptionSettingsFactoryBean implements FactoryBean<AutoEncry
 		return source != null ? source : Collections.emptyMap();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see  org.springframework.beans.factory.FactoryBean#getObjectType()
-	 */
 	@Override
 	public Class<?> getObjectType() {
 		return AutoEncryptionSettings.class;

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

@@ -21,6 +21,7 @@ import java.util.HashSet;
 import java.util.Set;
 
 import org.bson.BsonInvalidOperationException;
+
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.DataAccessResourceFailureException;
 import org.springframework.dao.DataIntegrityViolationException;
@@ -39,6 +40,7 @@ import org.springframework.util.ClassUtils;
 import com.mongodb.MongoBulkWriteException;
 import com.mongodb.MongoException;
 import com.mongodb.MongoServerException;
+import com.mongodb.MongoSocketException;
 import com.mongodb.bulk.BulkWriteError;
 
 /**
@@ -49,6 +51,7 @@ import com.mongodb.bulk.BulkWriteError;
  * @author Oliver Gierke
  * @author Michal Vich
  * @author Christoph Strobl
+ * @author Brice Vandeputte
  */
 public class MongoExceptionTranslator implements PersistenceExceptionTranslator {
 
@@ -65,10 +68,6 @@ public class MongoExceptionTranslator implements PersistenceExceptionTranslator
 	private static final Set<String> DATA_INTEGRITY_EXCEPTIONS = new HashSet<>(
 			Arrays.asList("WriteConcernException", "MongoWriteException", "MongoBulkWriteException"));
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.dao.support.PersistenceExceptionTranslator#translateExceptionIfPossible(java.lang.RuntimeException)
-	 */
 	@Nullable
 	public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
 
@@ -78,6 +77,10 @@ public class MongoExceptionTranslator implements PersistenceExceptionTranslator
 			throw new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
 		}
 
+		if (ex instanceof MongoSocketException) {
+			return new DataAccessResourceFailureException(ex.getMessage(), ex);
+		}
+
 		String exception = ClassUtils.getShortName(ClassUtils.getUserClass(ex.getClass()));
 
 		if (DUPLICATE_KEY_EXCEPTIONS.contains(exception)) {

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

@@ -15,7 +15,23 @@
  */
 package org.springframework.data.mongodb.core;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
+import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
+import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+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.mapping.Unwrapped.Nullable;
+import org.springframework.data.mongodb.core.schema.JsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
 import org.springframework.util.Assert;
 
@@ -24,6 +40,7 @@ import org.springframework.util.Assert;
  * following mapping rules.
  * <p>
  * <strong>Required Properties</strong>
+ * </p>
  * <ul>
  * <li>Properties of primitive type</li>
  * </ul>
@@ -45,7 +62,8 @@ import org.springframework.util.Assert;
  * {@link org.springframework.data.annotation.Id _id} properties using types that can be converted into
  * {@link org.bson.types.ObjectId} like {@link String} will be mapped to {@code type : 'object'} unless there is more
  * specific information available via the {@link org.springframework.data.mongodb.core.mapping.MongoId} annotation.
- * </p>
+
+ * {@link Encrypted} properties will contain {@literal encrypt} information.
  *
  * @author Christoph Strobl
  * @since 2.2
@@ -60,6 +78,88 @@ public interface MongoJsonSchemaCreator {
 	 */
 	MongoJsonSchema createSchemaFor(Class<?> type);
 
+	/**
+	 * Filter matching {@link JsonSchemaProperty properties}.
+	 *
+	 * @param filter the {@link Predicate} to evaluate for inclusion. Must not be {@literal null}.
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	MongoJsonSchemaCreator filter(Predicate<JsonSchemaPropertyContext> filter);
+
+	/**
+	 * The context in which a specific {@link #getProperty()} is encountered during schema creation.
+	 * 
+	 * @since 3.3
+	 */
+	interface JsonSchemaPropertyContext {
+
+		/**
+		 * The path to a given field/property in dot notation.
+		 * 
+		 * @return never {@literal null}.
+		 */
+		String getPath();
+
+		/**
+		 * The current property.
+		 * 
+		 * @return never {@literal null}.
+		 */
+		MongoPersistentProperty getProperty();
+
+		/**
+		 * Obtain the {@link MongoPersistentEntity} for a given property.
+		 * 
+		 * @param property must not be {@literal null}.
+		 * @param <T>
+		 * @return {@literal null} if the property is not an entity. It is nevertheless recommend to check
+		 *         {@link PersistentProperty#isEntity()} first.
+		 */
+		@Nullable
+		<T> MongoPersistentEntity<T> resolveEntity(MongoPersistentProperty property);
+
+	}
+
+	/**
+	 * A filter {@link Predicate} that matches {@link Encrypted encrypted properties} and those having nested ones.
+	 *
+	 * @return new instance of {@link Predicate}.
+	 * @since 3.3
+	 */
+	static Predicate<JsonSchemaPropertyContext> encryptedOnly() {
+
+		return new Predicate<JsonSchemaPropertyContext>() {
+
+			// cycle guard
+			private final Set<MongoPersistentProperty> seen = new HashSet<>();
+
+			@Override
+			public boolean test(JsonSchemaPropertyContext context) {
+				return extracted(context.getProperty(), context);
+			}
+
+			private boolean extracted(MongoPersistentProperty property, JsonSchemaPropertyContext context) {
+				if (property.isAnnotationPresent(Encrypted.class)) {
+					return true;
+				}
+
+				if (!property.isEntity() || seen.contains(property)) {
+					return false;
+				}
+
+				seen.add(property);
+
+				for (MongoPersistentProperty nested : context.resolveEntity(property)) {
+					if (extracted(nested, context)) {
+						return true;
+					}
+				}
+				return false;
+			}
+		};
+	}
+
 	/**
 	 * Creates a new {@link MongoJsonSchemaCreator} that is aware of conversions applied by the given
 	 * {@link MongoConverter}.
@@ -72,4 +172,41 @@ public interface MongoJsonSchemaCreator {
 		Assert.notNull(mongoConverter, "MongoConverter must not be null!");
 		return new MappingMongoJsonSchemaCreator(mongoConverter);
 	}
+
+	/**
+	 * Creates a new {@link MongoJsonSchemaCreator} that is aware of type mappings and potential
+	 * {@link org.springframework.data.spel.spi.EvaluationContextExtension extensions}.
+	 *
+	 * @param mappingContext must not be {@literal null}.
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	static MongoJsonSchemaCreator create(MappingContext mappingContext) {
+
+		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mappingContext);
+		converter.setCustomConversions(MongoCustomConversions.create(config -> {}));
+		converter.afterPropertiesSet();
+
+		return create(converter);
+	}
+
+	/**
+	 * Creates a new {@link MongoJsonSchemaCreator} that does not consider potential extensions - suitable for testing. We
+	 * recommend to use {@link #create(MappingContext)}.
+	 *
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	static MongoJsonSchemaCreator create() {
+
+		MongoMappingContext mappingContext = new MongoMappingContext();
+		mappingContext.setSimpleTypeHolder(MongoSimpleTypes.HOLDER);
+		mappingContext.afterPropertiesSet();
+
+		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mappingContext);
+		converter.setCustomConversions(MongoCustomConversions.create(config -> {}));
+		converter.afterPropertiesSet();
+
+		return create(converter);
+	}
 }

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

@@ -58,7 +58,7 @@ import com.mongodb.client.result.UpdateResult;
  * Interface that specifies a basic set of MongoDB operations. Implemented by {@link MongoTemplate}. Not often used but
  * a useful option for extensibility and testability (as it can be easily mocked, stubbed, or be the target of a JDK
  * proxy).
- * <p/>
+ * <br />
  * <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>.
@@ -125,7 +125,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Executes a {@link DbCallback} translating any exceptions as necessary.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param action callback object that specifies the MongoDB actions to perform on the passed in DB instance. Must not
@@ -138,7 +138,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Executes the given {@link CollectionCallback} on the entity collection of the specified class.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
@@ -151,7 +151,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Executes the given {@link CollectionCallback} on the collection of the given name.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param collectionName the name of the collection that specifies which {@link MongoCollection} instance will be
@@ -176,7 +176,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Obtain a {@link ClientSession session} bound instance of {@link SessionScoped} binding the {@link ClientSession}
 	 * provided by the given {@link Supplier} to each and every command issued against MongoDB.
-	 * <p/>
+	 * <br />
 	 * <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}.
 	 *
@@ -212,7 +212,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Obtain a {@link ClientSession} bound instance of {@link MongoOperations}.
-	 * <p/>
+	 * <br />
 	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle.
 	 *
 	 * @param session must not be {@literal null}.
@@ -300,7 +300,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * 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/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection. Must not be {@literal null}.
@@ -310,7 +310,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Check to see if a collection with a name indicated by the entity class exists.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param entityClass class that determines the name of the collection. Must not be {@literal null}.
@@ -320,7 +320,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Check to see if a collection with a given name exists.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection. Must not be {@literal null}.
@@ -330,7 +330,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Drop the collection with the name indicated by the entity class.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param entityClass class that determines the collection to drop/delete. Must not be {@literal null}.
@@ -339,7 +339,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Drop the collection with the given name.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection to drop/delete.
@@ -403,10 +403,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Query for a list of objects of type T from the collection used by the entity class.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
@@ -417,10 +417,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Query for a list of objects of type T from the specified collection.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
@@ -539,11 +539,11 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation backed by a Mongo DB {@link com.mongodb.client.AggregateIterable}.
-	 * <p/>
+	 * <br />
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link com.mongodb.client.AggregateIterable} that
 	 * needs to be closed. The raw results will be mapped to the given entity class and are returned as stream. The name
 	 * of the inputCollection is derived from the inputType of the aggregation.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming can't be used with {@link AggregationOptions#isExplain() aggregation explain}. Enabling
 	 * explanation mode will throw an {@link IllegalArgumentException}.
 	 *
@@ -557,10 +557,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation backed by a Mongo DB {@link com.mongodb.client.AggregateIterable}.
-	 * <p/>
+	 * <br />
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link com.mongodb.client.AggregateIterable} that
 	 * needs to be closed. The raw results will be mapped to the given entity class.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming can't be used with {@link AggregationOptions#isExplain() aggregation explain}. Enabling
 	 * explanation mode will throw an {@link IllegalArgumentException}.
 	 *
@@ -576,10 +576,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation backed by a Mongo DB {@link com.mongodb.client.AggregateIterable}.
-	 * <p/>
+	 * <br />
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link com.mongodb.client.AggregateIterable} that
 	 * needs to be closed. The raw results will be mapped to the given entity class.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming can't be used with {@link AggregationOptions#isExplain() aggregation explain}. Enabling
 	 * explanation mode will throw an {@link IllegalArgumentException}.
 	 *
@@ -702,10 +702,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity class to a single instance of an object of the
 	 * specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -720,10 +720,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the specified collection to a single instance of an object of the specified
 	 * type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -768,10 +768,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity class to a List of the specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -784,10 +784,10 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Map the results of an ad-hoc query on the specified collection to a List of the specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -881,7 +881,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	}
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * 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
@@ -897,7 +897,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, UpdateDefinition update, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * 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
@@ -914,7 +914,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, UpdateDefinition update, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * 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.
 	 *
@@ -934,7 +934,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	<T> T findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * 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.
 	 *
@@ -957,7 +957,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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 />
@@ -977,7 +977,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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 />
@@ -997,7 +997,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -1018,7 +1018,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -1041,7 +1041,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -1066,7 +1066,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -1094,7 +1094,7 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -1120,9 +1120,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * 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
 	 * database.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -1137,10 +1137,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the specified collection 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 database.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -1160,6 +1160,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(Class)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -1176,6 +1182,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(String)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
@@ -1187,6 +1199,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Estimate the number of documents, in the collection {@link #getCollectionName(Class) identified by the given type},
 	 * based on collection statistics.
+	 * <br />
+	 * Please make sure to read the MongoDB reference documentation about limitations on eg. sharded cluster or inside
+	 * transactions.
 	 *
 	 * @param entityClass must not be {@literal null}.
 	 * @return the estimated number of documents.
@@ -1200,6 +1215,9 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Estimate the number of documents in the given collection based on collection statistics.
+	 * <br />
+	 * Please make sure to read the MongoDB reference documentation about limitations on eg. sharded cluster or inside
+	 * transactions.
 	 *
 	 * @param collectionName must not be {@literal null}.
 	 * @return the estimated number of documents.
@@ -1214,6 +1232,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(String)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -1225,34 +1249,39 @@ public interface MongoOperations extends FluentMongoOperations {
 
 	/**
 	 * Insert the object into the collection for the entity type of the object to save.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
 	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
 	 * Type Conversion"</a> for more details.
-	 * <p/>
-	 * <p/>
+	 * <br />
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the inserted object.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> T insert(T objectToSave);
 
 	/**
 	 * Insert the object into the specified collection.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @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.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> T insert(T objectToSave, String collectionName);
 
@@ -1286,37 +1315,42 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Save the object to the collection for the entity type of the object to save. This will perform an insert if the
 	 * object is not already present, that is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
 	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
 	 * Type Conversion"</a> for more details.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<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
 	 * is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
-	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See <a
-	 * https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type
-	 * Conversion"</a> for more details.
+	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API.
+	 * See <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type Conversion</a> for more details.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @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.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> T save(T objectToSave, String collectionName);
 

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

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core;
+
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
+
+import com.mongodb.ServerApi;
+import com.mongodb.ServerApi.Builder;
+import com.mongodb.ServerApiVersion;
+
+/**
+ * {@link FactoryBean} for creating {@link ServerApi} using the {@link ServerApi.Builder}.
+ *
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+public class MongoServerApiFactoryBean implements FactoryBean<ServerApi> {
+
+	private String version;
+	private @Nullable Boolean deprecationErrors;
+	private @Nullable Boolean strict;
+
+	/**
+	 * @param version the version string either as the enum name or the server version value.
+	 * @see ServerApiVersion
+	 */
+	public void setVersion(String version) {
+		this.version = version;
+	}
+
+	/**
+	 * @param deprecationErrors
+	 * @see ServerApi.Builder#deprecationErrors(boolean)
+	 */
+	public void setDeprecationErrors(@Nullable Boolean deprecationErrors) {
+		this.deprecationErrors = deprecationErrors;
+	}
+
+	/**
+	 * @param strict
+	 * @see ServerApi.Builder#strict(boolean)
+	 */
+	public void setStrict(@Nullable Boolean strict) {
+		this.strict = strict;
+	}
+
+	@Nullable
+	@Override
+	public ServerApi getObject() throws Exception {
+
+		Builder builder = ServerApi.builder().version(version());
+
+		if (deprecationErrors != null) {
+			builder = builder.deprecationErrors(deprecationErrors);
+		}
+		if (strict != null) {
+			builder = builder.strict(strict);
+		}
+		return builder.build();
+	}
+
+	@Nullable
+	@Override
+	public Class<?> getObjectType() {
+		return ServerApi.class;
+	}
+
+	private ServerApiVersion version() {
+		try {
+			// lookup by name eg. 'V1'
+			return ObjectUtils.caseInsensitiveValueOf(ServerApiVersion.values(), version);
+		} catch (IllegalArgumentException e) {
+			// or just the version number, eg. just '1'
+			return ServerApiVersion.findByValue(version);
+		}
+	}
+}

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

@@ -16,18 +16,19 @@
 package org.springframework.data.mongodb.core;
 
 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;
+import org.springframework.data.mongodb.core.mapping.PersistentPropertyTranslator;
+import org.springframework.data.projection.EntityProjection;
+import org.springframework.data.util.Predicates;
 
 /**
  * Common operations performed on properties of an entity like extracting fields information for projection creation.
  *
  * @author Christoph Strobl
+ * @author Mark Paluch
  * @since 2.1
  */
 class PropertyOperations {
@@ -40,37 +41,37 @@ class PropertyOperations {
 
 	/**
 	 * 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
+	 * creating the projection (target) type if the {@code EntityProjection} is a {@literal DTO projection} or a
 	 * {@literal closed interface projection}.
 	 *
-	 * @param projectionFactory must not be {@literal null}.
+	 * @param projection 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) {
+	Document computeMappedFieldsForProjection(EntityProjection<?, ?> projection,
+			Document fields) {
 
-		if (!fields.isEmpty() || ClassUtils.isAssignable(domainType, targetType)) {
+		if (!projection.isClosedProjection()) {
 			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));
-			}
+		if (projection.getMappedType().getType().isInterface()) {
+			projection.forEach(it -> {
+				projectedFields.put(it.getPropertyPath().getSegment(), 1);
+			});
 		} else {
 
-			MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(targetType);
-			if (entity != null) {
-				entity.doWithProperties(
-						(SimplePropertyHandler) persistentProperty -> projectedFields.append(persistentProperty.getName(), 1));
+			// DTO projections use merged metadata between domain type and result type
+			PersistentPropertyTranslator translator = PersistentPropertyTranslator.create(
+					mappingContext.getRequiredPersistentEntity(projection.getDomainType()),
+					Predicates.negate(MongoPersistentProperty::hasExplicitFieldName));
+
+			MongoPersistentEntity<?> persistentEntity = mappingContext
+					.getRequiredPersistentEntity(projection.getMappedType());
+			for (MongoPersistentProperty property : persistentEntity) {
+				projectedFields.put(translator.translate(property).getFieldName(), 1);
 			}
 		}
 

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

@@ -17,6 +17,7 @@ package org.springframework.data.mongodb.core;
 
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -27,15 +28,22 @@ import java.util.stream.Collectors;
 import org.bson.BsonValue;
 import org.bson.Document;
 import org.bson.codecs.Codec;
+
 import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.mapping.PropertyReferenceException;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.CodecRegistryProvider;
+import org.springframework.data.mongodb.MongoExpression;
 import org.springframework.data.mongodb.core.MappedDocument.MappedUpdate;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
+import org.springframework.data.mongodb.core.aggregation.AggregationExpression;
 import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
+import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
+import org.springframework.data.mongodb.core.aggregation.AggregationPipeline;
 import org.springframework.data.mongodb.core.aggregation.AggregationUpdate;
 import org.springframework.data.mongodb.core.aggregation.RelaxedTypeBasedAggregationOperationContext;
+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.convert.UpdateMapper;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
@@ -47,10 +55,10 @@ import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.UpdateDefinition;
 import org.springframework.data.mongodb.core.query.UpdateDefinition.ArrayFilter;
 import org.springframework.data.mongodb.util.BsonUtils;
-import org.springframework.data.projection.ProjectionFactory;
+import org.springframework.data.projection.EntityProjection;
+import org.springframework.data.util.Lazy;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 import com.mongodb.client.model.CountOptions;
@@ -194,9 +202,34 @@ class QueryOperations {
 		return new DeleteContext(query, false);
 	}
 
+	/**
+	 * Create a new {@link AggregationDefinition} for the given {@link Aggregation}.
+	 *
+	 * @param aggregation must not be {@literal null}.
+	 * @param inputType fallback mapping type in case of untyped aggregation. Can be {@literal null}.
+	 * @return new instance of {@link AggregationDefinition}.
+	 * @since 3.2
+	 */
+	AggregationDefinition createAggregation(Aggregation aggregation, @Nullable Class<?> inputType) {
+		return new AggregationDefinition(aggregation, inputType);
+	}
+
+	/**
+	 * Create a new {@link AggregationDefinition} for the given {@link Aggregation}.
+	 *
+	 * @param aggregation must not be {@literal null}.
+	 * @param aggregationOperationContext the {@link AggregationOperationContext} to use. Can be {@literal null}.
+	 * @return new instance of {@link AggregationDefinition}.
+	 * @since 3.2
+	 */
+	AggregationDefinition createAggregation(Aggregation aggregation,
+			@Nullable AggregationOperationContext aggregationOperationContext) {
+		return new AggregationDefinition(aggregation, aggregationOperationContext);
+	}
+
 	/**
 	 * {@link QueryContext} encapsulates common tasks required to convert a {@link Query} into its MongoDB document
-	 * representation, mapping fieldnames, as well as determinging and applying {@link Collation collations}.
+	 * representation, mapping field names, as well as determining and applying {@link Collation collations}.
 	 *
 	 * @author Christoph Strobl
 	 */
@@ -205,7 +238,7 @@ class QueryOperations {
 		private final Query query;
 
 		/**
-		 * Create new a {@link QueryContext} instance from the given {@literal query} (can be eihter a {@link Query} or a
+		 * Create new a {@link QueryContext} instance from the given {@literal query} (can be either a {@link Query} or a
 		 * plain {@link Document}.
 		 *
 		 * @param query can be {@literal null}.
@@ -255,33 +288,61 @@ class QueryOperations {
 			return queryMapper.getMappedObject(getQueryObject(), entity);
 		}
 
-		Document getMappedFields(@Nullable MongoPersistentEntity<?> entity, Class<?> targetType,
-				ProjectionFactory projectionFactory) {
+		Document getMappedFields(@Nullable MongoPersistentEntity<?> entity,
+				EntityProjection<?, ?> projection) {
 
-			Document fields = query.getFieldsObject();
-			Document mappedFields = fields;
+			Document fields = evaluateFields(entity);
 
 			if (entity == null) {
-				return mappedFields;
+				return fields;
 			}
 
-			Document projectedFields = propertyOperations.computeFieldsForProjection(projectionFactory, fields,
-					entity.getType(), targetType);
-
-			if (ObjectUtils.nullSafeEquals(fields, projectedFields)) {
-				mappedFields = queryMapper.getMappedFields(projectedFields, entity);
+			Document mappedFields;
+			if (!fields.isEmpty()) {
+				mappedFields = queryMapper.getMappedFields(fields, entity);
 			} else {
-				mappedFields = queryMapper.getMappedFields(projectedFields,
-						mappingContext.getRequiredPersistentEntity(targetType));
+				mappedFields = propertyOperations.computeMappedFieldsForProjection(projection, fields);
+				mappedFields = queryMapper.addMetaAttributes(mappedFields, entity);
 			}
 
-			if (entity != null && entity.hasTextScoreProperty() && !query.getQueryObject().containsKey("$text")) {
+			if (entity.hasTextScoreProperty() && mappedFields.containsKey(entity.getTextScoreProperty().getFieldName())
+					&& !query.getQueryObject().containsKey("$text")) {
 				mappedFields.remove(entity.getTextScoreProperty().getFieldName());
 			}
 
+			if (mappedFields.isEmpty()) {
+				return BsonUtils.EMPTY_DOCUMENT;
+			}
+
 			return mappedFields;
 		}
 
+		private Document evaluateFields(@Nullable MongoPersistentEntity<?> entity) {
+
+			Document fields = query.getFieldsObject();
+
+			if (fields.isEmpty()) {
+				return BsonUtils.EMPTY_DOCUMENT;
+			}
+
+			Document evaluated = new Document();
+
+			for (Entry<String, Object> entry : fields.entrySet()) {
+
+				if (entry.getValue() instanceof MongoExpression) {
+
+					AggregationOperationContext ctx = entity == null ? Aggregation.DEFAULT_CONTEXT
+							: new RelaxedTypeBasedAggregationOperationContext(entity.getType(), mappingContext, queryMapper);
+
+					evaluated.put(entry.getKey(), AggregationExpression.from((MongoExpression) entry.getValue()).toDocument(ctx));
+				} else {
+					evaluated.put(entry.getKey(), entry.getValue());
+				}
+			}
+
+			return evaluated;
+		}
+
 		/**
 		 * Get the already mapped {@link Query#getSortObject() sort} option.
 		 *
@@ -341,7 +402,8 @@ class QueryOperations {
 		}
 
 		@Override
-		Document getMappedFields(@Nullable MongoPersistentEntity<?> entity, Class<?> targetType, ProjectionFactory projectionFactory) {
+		Document getMappedFields(@Nullable MongoPersistentEntity<?> entity,
+				EntityProjection<?, ?> projection) {
 			return getMappedFields(entity);
 		}
 
@@ -565,7 +627,7 @@ class QueryOperations {
 
 		UpdateContext(MappedDocument update, boolean upsert) {
 
-			super(new BasicQuery(new Document(BsonUtils.asMap(update.getIdFilter()))));
+			super(new BasicQuery(BsonUtils.asDocument(update.getIdFilter())));
 			this.multi = false;
 			this.upsert = upsert;
 			this.mappedDocument = update;
@@ -658,7 +720,8 @@ class QueryOperations {
 					: mappedDocument != null ? mappedDocument.getDocument() : getMappedUpdate(domainType);
 
 			Document filterWithShardKey = new Document(filter);
-			getMappedShardKeyFields(domainType).forEach(key -> filterWithShardKey.putIfAbsent(key, shardKeySource.get(key)));
+			getMappedShardKeyFields(domainType)
+					.forEach(key -> filterWithShardKey.putIfAbsent(key, BsonUtils.resolveValue(shardKeySource, key)));
 
 			return filterWithShardKey;
 		}
@@ -709,7 +772,8 @@ class QueryOperations {
 
 			Class<?> type = domainType != null ? domainType : Object.class;
 
-			AggregationOperationContext context = new RelaxedTypeBasedAggregationOperationContext(type, mappingContext, queryMapper);
+			AggregationOperationContext context = new RelaxedTypeBasedAggregationOperationContext(type, mappingContext,
+					queryMapper);
 			return aggregationUtil.createPipeline((AggregationUpdate) update, context);
 		}
 
@@ -759,4 +823,105 @@ class QueryOperations {
 			return multi;
 		}
 	}
+
+	/**
+	 * A value object that encapsulates common tasks required when running {@literal aggregations}.
+	 *
+	 * @since 3.2
+	 */
+	class AggregationDefinition {
+
+		private final Aggregation aggregation;
+		private final Lazy<AggregationOperationContext> aggregationOperationContext;
+		private final Lazy<List<Document>> pipeline;
+		private final @Nullable Class<?> inputType;
+
+		/**
+		 * Creates new instance of {@link AggregationDefinition} extracting the input type from either the
+		 * {@link org.springframework.data.mongodb.core.aggregation.Aggregation} in case of a {@link TypedAggregation} or
+		 * the given {@literal aggregationOperationContext} if present. <br />
+		 * Creates a new {@link AggregationOperationContext} if none given, based on the {@link Aggregation} input type and
+		 * the desired {@link AggregationOptions#getDomainTypeMapping() domain type mapping}. <br />
+		 * Pipelines are mapped on first access of {@link #getAggregationPipeline()} and cached for reuse.
+		 *
+		 * @param aggregation the source aggregation.
+		 * @param aggregationOperationContext can be {@literal null}.
+		 */
+		AggregationDefinition(Aggregation aggregation, @Nullable AggregationOperationContext aggregationOperationContext) {
+
+			this.aggregation = aggregation;
+
+			if (aggregation instanceof TypedAggregation) {
+				this.inputType = ((TypedAggregation<?>) aggregation).getInputType();
+			} else if (aggregationOperationContext instanceof TypeBasedAggregationOperationContext) {
+				this.inputType = ((TypeBasedAggregationOperationContext) aggregationOperationContext).getType();
+			} else {
+				this.inputType = null;
+			}
+
+			this.aggregationOperationContext = Lazy.of(() -> aggregationOperationContext != null ? aggregationOperationContext
+					: aggregationUtil.createAggregationContext(aggregation, getInputType()));
+			this.pipeline = Lazy.of(() -> aggregationUtil.createPipeline(this.aggregation, getAggregationOperationContext()));
+		}
+
+		/**
+		 * Creates new instance of {@link AggregationDefinition} extracting the input type from either the
+		 * {@link org.springframework.data.mongodb.core.aggregation.Aggregation} in case of a {@link TypedAggregation} or
+		 * the given {@literal aggregationOperationContext} if present. <br />
+		 * Creates a new {@link AggregationOperationContext} based on the {@link Aggregation} input type and the desired
+		 * {@link AggregationOptions#getDomainTypeMapping() domain type mapping}. <br />
+		 * Pipelines are mapped on first access of {@link #getAggregationPipeline()} and cached for reuse.
+		 *
+		 * @param aggregation the source aggregation.
+		 * @param inputType can be {@literal null}.
+		 */
+		AggregationDefinition(Aggregation aggregation, @Nullable Class<?> inputType) {
+
+			this.aggregation = aggregation;
+
+			if (aggregation instanceof TypedAggregation) {
+				this.inputType = ((TypedAggregation<?>) aggregation).getInputType();
+			} else {
+				this.inputType = inputType;
+			}
+
+			this.aggregationOperationContext = Lazy
+					.of(() -> aggregationUtil.createAggregationContext(aggregation, getInputType()));
+			this.pipeline = Lazy.of(() -> aggregationUtil.createPipeline(this.aggregation, getAggregationOperationContext()));
+		}
+
+		/**
+		 * Obtain the already mapped pipeline.
+		 *
+		 * @return never {@literal null}.
+		 */
+		List<Document> getAggregationPipeline() {
+			return pipeline.get();
+		}
+
+		/**
+		 * @return {@literal true} if the last aggregation stage is either {@literal $out} or {@literal $merge}.
+		 * @see AggregationPipeline#isOutOrMerge()
+		 */
+		boolean isOutOrMerge() {
+			return aggregation.getPipeline().isOutOrMerge();
+		}
+
+		/**
+		 * Obtain the {@link AggregationOperationContext} used for mapping the pipeline.
+		 *
+		 * @return never {@literal null}.
+		 */
+		AggregationOperationContext getAggregationOperationContext() {
+			return aggregationOperationContext.get();
+		}
+
+		/**
+		 * @return the input type to map the pipeline against. Can be {@literal null}.
+		 */
+		@Nullable
+		Class<?> getInputType() {
+			return inputType;
+		}
+	}
 }

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

@@ -46,10 +46,6 @@ class ReactiveAggregationOperationSupport implements ReactiveAggregationOperatio
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveAggregationOperation#aggregateAndReturn(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveAggregation<T> aggregateAndReturn(Class<T> domainType) {
 
@@ -75,10 +71,6 @@ class ReactiveAggregationOperationSupport implements ReactiveAggregationOperatio
 			this.collection = collection;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveAggregationOperation.AggregationOperationWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public AggregationOperationWithAggregation<T> inCollection(String collection) {
 
@@ -87,10 +79,6 @@ class ReactiveAggregationOperationSupport implements ReactiveAggregationOperatio
 			return new ReactiveAggregationSupport<>(template, domainType, aggregation, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveAggregationOperation.AggregationOperationWithAggregation#by(org.springframework.data.mongodb.core.Aggregation)
-		 */
 		@Override
 		public TerminatingAggregationOperation<T> by(Aggregation aggregation) {
 
@@ -99,10 +87,6 @@ class ReactiveAggregationOperationSupport implements ReactiveAggregationOperatio
 			return new ReactiveAggregationSupport<>(template, domainType, aggregation, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveAggregationOperation.TerminatingAggregationOperation#all()
-		 */
 		@Override
 		public Flux<T> all() {
 			return template.aggregate(aggregation, getCollectionName(aggregation), domainType);

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

@@ -71,7 +71,7 @@ public interface ReactiveChangeStreamOperation {
 		/**
 		 * Start listening to changes. The stream will not be completed unless the {@link org.reactivestreams.Subscription}
 		 * is {@link org.reactivestreams.Subscription#cancel() canceled}.
-		 * <p />
+		 * <br />
 		 * However, the stream may become dead, or invalid, if all watched collections, databases are dropped.
 		 */
 		Flux<ChangeStreamEvent<T>> listen();

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

@@ -46,10 +46,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation#changeStream(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveChangeStream<T> changeStream(Class<T> domainType) {
 
@@ -76,10 +72,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			this.options = options;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithCollection#watchCollection(java.lang.String)
-		 */
 		@Override
 		public ChangeStreamWithFilterAndProjection<T> watchCollection(String collection) {
 
@@ -88,10 +80,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return new ReactiveChangeStreamSupport<>(template, domainType, returnType, collection, options);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithCollection#watchCollection(java.lang.Class)
-		 */
 		@Override
 		public ChangeStreamWithFilterAndProjection<T> watchCollection(Class<?> entityClass) {
 
@@ -100,10 +88,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return watchCollection(template.getCollectionName(entityClass));
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#resumeAt(java.lang.Object)
-		 */
 		@Override
 		public TerminatingChangeStream<T> resumeAt(Object token) {
 
@@ -117,10 +101,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			});
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#resumeAfter(java.lang.Object)
-		 */
 		@Override
 		public TerminatingChangeStream<T> resumeAfter(Object token) {
 
@@ -129,10 +109,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return withOptions(builder -> builder.resumeAfter((BsonValue) token));
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ResumingChangeStream#startAfter(java.lang.Object)
-		 */
 		@Override
 		public TerminatingChangeStream<T> startAfter(Object token) {
 
@@ -141,10 +117,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return withOptions(builder -> builder.startAfter((BsonValue) token));
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithOptions#withOptions(java.util.function.Consumer)
-		 */
 		@Override
 		public ReactiveChangeStreamSupport<T> withOptions(Consumer<ChangeStreamOptionsBuilder> optionsConsumer) {
 
@@ -154,10 +126,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return new ReactiveChangeStreamSupport<>(template, domainType, returnType, collection, builder.build());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithProjection#as(java.lang.Class)
-		 */
 		@Override
 		public <R> ChangeStreamWithFilterAndProjection<R> as(Class<R> resultType) {
 
@@ -166,19 +134,11 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return new ReactiveChangeStreamSupport<>(template, domainType, resultType, collection, options);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithFilter#filter(org.springframework.data.mongodb.core.aggregation.Aggregation)
-		 */
 		@Override
 		public ChangeStreamWithFilterAndProjection<T> filter(Aggregation filter) {
 			return withOptions(builder -> builder.filter(filter));
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.ChangeStreamWithFilter#filter(org.springframework.data.mongodb.core.query.CriteriaDefinition)
-		 */
 		@Override
 		public ChangeStreamWithFilterAndProjection<T> filter(CriteriaDefinition by) {
 
@@ -188,10 +148,6 @@ class ReactiveChangeStreamOperationSupport implements ReactiveChangeStreamOperat
 			return filter(aggregation);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveChangeStreamOperation.TerminatingChangeStream#listen()
-		 */
 		@Override
 		public Flux<ChangeStreamEvent<T>> listen() {
 			return template.changeStream(collection, options != null ? options : ChangeStreamOptions.empty(), returnType);

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

@@ -91,10 +91,10 @@ public interface ReactiveFindOperation {
 		 * 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 />
+		 * <br />
 		 * 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 />
+		 * <br />
 		 * 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.
@@ -106,6 +106,12 @@ public interface ReactiveFindOperation {
 
 		/**
 		 * Get the number of matching elements.
+		 * <br />
+		 * This method uses an
+		 * {@link com.mongodb.reactivestreams.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+		 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but
+		 * guarantees shard, session and transaction compliance. In case an inaccurate count satisfies the applications
+		 * needs use {@link ReactiveMongoOperations#estimatedCount(String)} for empty queries instead.
 		 *
 		 * @return {@link Mono} emitting total number of matching elements. Never {@literal null}.
 		 */

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

@@ -44,10 +44,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveFindOperation#query(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveFind<T> query(Class<T> domainType) {
 
@@ -81,10 +77,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			this.query = query;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.FindWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public FindWithProjection<T> inCollection(String collection) {
 
@@ -93,10 +85,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return new ReactiveFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.FindWithProjection#as(java.lang.Class)
-		 */
 		@Override
 		public <T1> FindWithQuery<T1> as(Class<T1> returnType) {
 
@@ -105,10 +93,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return new ReactiveFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.FindWithQuery#matching(org.springframework.data.mongodb.core.query.Query)
-		 */
 		@Override
 		public TerminatingFind<T> matching(Query query) {
 
@@ -117,10 +101,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return new ReactiveFindSupport<>(template, domainType, returnType, collection, query);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#first()
-		 */
 		@Override
 		public Mono<T> first() {
 
@@ -130,10 +110,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			return result.next();
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#one()
-		 */
 		@Override
 		public Mono<T> one() {
 
@@ -155,55 +131,31 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			});
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#all()
-		 */
 		@Override
 		public Flux<T> all() {
 			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)
-		 */
 		@Override
 		public TerminatingFindNear<T> near(NearQuery nearQuery) {
 			return () -> template.geoNear(nearQuery, domainType, getCollectionName(), returnType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#count()
-		 */
 		@Override
 		public Mono<Long> count() {
 			return template.count(query, domainType, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveFindOperation.TerminatingFind#exists()
-		 */
 		@Override
 		public Mono<Boolean> exists() {
 			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) {
 
@@ -255,10 +207,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 				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) {
 
@@ -267,10 +215,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 				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) {
@@ -280,10 +224,6 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 				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/ReactiveInsertOperationSupport.java

@@ -38,10 +38,6 @@ class ReactiveInsertOperationSupport implements ReactiveInsertOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveInsertOperation#insert(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveInsert<T> insert(Class<T> domainType) {
 
@@ -63,10 +59,6 @@ class ReactiveInsertOperationSupport implements ReactiveInsertOperation {
 			this.collection = collection;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveInsertOperation.TerminatingInsert#one(java.lang.Object)
-		 */
 		@Override
 		public Mono<T> one(T object) {
 
@@ -75,10 +67,6 @@ class ReactiveInsertOperationSupport implements ReactiveInsertOperation {
 			return template.insert(object, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveInsertOperation.TerminatingInsert#all(java.util.Collection)
-		 */
 		@Override
 		public Flux<T> all(Collection<? extends T> objects) {
 
@@ -87,10 +75,6 @@ class ReactiveInsertOperationSupport implements ReactiveInsertOperation {
 			return template.insert(objects, getCollectionName());
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveInsertOperation.InsertWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public ReactiveInsert<T> inCollection(String collection) {
 

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

@@ -59,7 +59,7 @@ 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 />
+ * <br />
  * <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>.
@@ -121,7 +121,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Executes a {@link ReactiveDatabaseCallback} translating any exceptions as necessary.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param action callback object that specifies the MongoDB actions to perform on the passed in DB instance. Must not
@@ -133,7 +133,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Executes the given {@link ReactiveCollectionCallback} on the entity collection of the specified class.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
@@ -145,7 +145,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Executes the given {@link ReactiveCollectionCallback} on the collection of the given name.
-	 * <p/>
+	 * <br />
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
 	 * @param collectionName the name of the collection that specifies which {@link MongoCollection} instance will be
@@ -159,7 +159,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * 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 />
+	 * <br />
 	 * <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.
@@ -178,7 +178,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * 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 />
+	 * <br />
 	 * <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.
@@ -192,7 +192,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * 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 />
+	 * <br />
 	 * <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.
@@ -205,7 +205,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Obtain a {@link ClientSession} bound instance of {@link ReactiveMongoOperations}.
-	 * <p />
+	 * <br />
 	 * <strong>Note:</strong> It is up to the caller to manage the {@link ClientSession} lifecycle.
 	 *
 	 * @param session must not be {@literal null}.
@@ -218,7 +218,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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/>
+	 * <br />
 	 * 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.
@@ -233,7 +233,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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/>
+	 * <br />
 	 * 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.
@@ -293,7 +293,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection.
@@ -303,7 +303,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Check to see if a collection with a name indicated by the entity class exists.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param entityClass class that determines the name of the collection. Must not be {@literal null}.
@@ -313,7 +313,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Check to see if a collection with a given name exists.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection. Must not be {@literal null}.
@@ -323,7 +323,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Drop the collection with the name indicated by the entity class.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param entityClass class that determines the collection to drop/delete. Must not be {@literal null}.
@@ -332,7 +332,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Drop the collection with the given name.
-	 * <p/>
+	 * <br />
 	 * Translate any exceptions as necessary.
 	 *
 	 * @param collectionName name of the collection to drop/delete.
@@ -341,10 +341,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Query for a {@link Flux} of objects of type T from the collection used by the entity class.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
@@ -355,10 +355,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Query for a {@link Flux} of objects of type T from the specified collection.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
@@ -371,10 +371,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity class to a single instance of an object of the
 	 * specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -388,10 +388,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the specified collection to a single instance of an object of the specified
 	 * type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -435,10 +435,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Map the results of an ad-hoc query on the collection for the entity class to a {@link Flux} of the specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -451,10 +451,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Map the results of an ad-hoc query on the specified collection to a {@link Flux} of the specified type.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -566,10 +566,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation.
-	 * <p/>
+	 * <br />
 	 * The raw results will be mapped to the given entity class and are returned as stream. The name of the
 	 * inputCollection is derived from the {@link TypedAggregation#getInputType() aggregation input type}.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming cannot be used with {@link AggregationOptions#isExplain() aggregation explain} nor with
 	 * {@link AggregationOptions#getCursorBatchSize()}. Enabling explanation mode or setting batch size cause
 	 * {@link IllegalArgumentException}.
@@ -584,10 +584,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation.
-	 * <p/>
+	 * <br />
 	 * The raw results will be mapped to the given {@code ouputType}. The name of the inputCollection is derived from the
 	 * {@code inputType}.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming cannot be used with {@link AggregationOptions#isExplain() aggregation explain} nor with
 	 * {@link AggregationOptions#getCursorBatchSize()}. Enabling explanation mode or setting batch size cause
 	 * {@link IllegalArgumentException}.
@@ -604,9 +604,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Execute an aggregation operation.
-	 * <p/>
+	 * <br />
 	 * The raw results will be mapped to the given entity class.
-	 * <p/>
+	 * <br />
 	 * Aggregation streaming cannot be used with {@link AggregationOptions#isExplain() aggregation explain} nor with
 	 * {@link AggregationOptions#getCursorBatchSize()}. Enabling explanation mode or setting batch size cause
 	 * {@link IllegalArgumentException}.
@@ -676,7 +676,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	<T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
+	 * 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
@@ -691,7 +691,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
+	 * 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
@@ -707,7 +707,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
+	 * 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.
 	 *
@@ -725,7 +725,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	<T> Mono<T> findAndModify(Query query, UpdateDefinition update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
+	 * 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.
 	 *
@@ -746,7 +746,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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 />
@@ -764,7 +764,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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 />
@@ -783,7 +783,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -803,7 +803,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -825,7 +825,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -849,7 +849,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -876,7 +876,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Triggers
-	 * <a href="https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndReplace/">findOneAndReplace<a/>
+	 * <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}.
@@ -902,9 +902,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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
 	 * database.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -918,10 +918,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Map the results of an ad-hoc query on the specified collection 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 database.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -940,6 +940,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.reactivestreams.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(Class)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -956,6 +962,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.reactivestreams.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(String)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
@@ -971,6 +983,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * influence on the resulting number of documents found as those values are passed on to the server and potentially
 	 * limit the range and order within which the server performs the count operation. Use an {@literal unpaged} query to
 	 * count all matches.
+	 * <br />
+	 * This method uses an
+	 * {@link com.mongodb.reactivestreams.client.MongoCollection#countDocuments(org.bson.conversions.Bson, com.mongodb.client.model.CountOptions)
+	 * aggregation execution} even for empty {@link Query queries} which may have an impact on performance, but guarantees
+	 * shard, session and transaction compliance. In case an inaccurate count satisfies the applications needs use
+	 * {@link #estimatedCount(String)} for empty queries instead.
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
 	 *          {@literal null}.
@@ -983,6 +1001,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Estimate the number of documents, in the collection {@link #getCollectionName(Class) identified by the given type},
 	 * based on collection statistics.
+	 * <br />
+	 * Please make sure to read the MongoDB reference documentation about limitations on eg. sharded cluster or inside
+	 * transactions.
 	 *
 	 * @param entityClass must not be {@literal null}.
 	 * @return a {@link Mono} emitting the estimated number of documents.
@@ -996,6 +1017,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Estimate the number of documents in the given collection based on collection statistics.
+	 * <br />
+	 * Please make sure to read the MongoDB reference documentation about limitations on eg. sharded cluster or inside
+	 * transactions.
 	 *
 	 * @param collectionName must not be {@literal null}.
 	 * @return a {@link Mono} emitting the estimated number of documents.
@@ -1005,34 +1029,39 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Insert the object into the collection for the entity type of the object to save.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
 	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
 	 * Type Conversion"</a> for more details.
-	 * <p/>
-	 * <p/>
+	 * <br />
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the inserted object.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> Mono<T> insert(T objectToSave);
 
 	/**
 	 * Insert the object into the specified collection.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @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.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> Mono<T> insert(T objectToSave, String collectionName);
 
@@ -1065,16 +1094,15 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 
 	/**
 	 * Insert the object into the collection for the entity type of the object to save.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
 	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
 	 * Type Conversion"</a> for more details.
-	 * <p/>
-	 * <p/>
+	 * <br />
 	 * 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}.
@@ -1112,52 +1140,54 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Save the object to the collection for the entity type of the object to save. This will perform an insert if the
 	 * object is not already present, that is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
 	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
 	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
 	 * Type Conversion"</a> for more details.
+	 * <br />
+	 * The {@code objectToSave} must not be collection-like.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> Mono<T> save(T objectToSave);
 
 	/**
 	 * Save the object to the specified collection. This will perform an insert if the object is not already present, that
 	 * is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
-	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See <a
-	 * https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type
-	 * Conversion"</a> for more details.
+	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API.
+	 * See <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type Conversion</a> for more details.
 	 *
 	 * @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.
+	 * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
 	 */
 	<T> Mono<T> save(T objectToSave, String collectionName);
 
 	/**
 	 * Save the object to the collection for the entity type of the object to save. This will perform an insert if the
 	 * object is not already present, that is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
-	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
-	 * <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation" > Spring's
-	 * Type Conversion"</a> for more details.
+	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API.
+	 * See <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation"> Spring's Type Conversion</a> for more details.
 	 *
 	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
 	 * @return the saved object.
@@ -1167,17 +1197,16 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Save the object to the specified collection. This will perform an insert if the object is not already present, that
 	 * is an 'upsert'.
-	 * <p/>
+	 * <br />
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * If your object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
-	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See <a
-	 * https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type
-	 * Conversion"</a> for more details.
+	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API.
+	 * See <a href="https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type Conversion</a> for more details.
 	 *
-	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @param objectToSave the object to store in the collReactiveMongoOperationsection. 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.
 	 */
@@ -1449,10 +1478,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * type. The stream uses a {@link com.mongodb.CursorType#TailableAwait tailable} cursor that may be an infinite
 	 * stream. The stream will not be completed unless the {@link org.reactivestreams.Subscription} is
 	 * {@link Subscription#cancel() canceled}.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -1468,10 +1497,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * type. The stream uses a {@link com.mongodb.CursorType#TailableAwait tailable} cursor that may be an infinite
 	 * stream. The stream will not be completed unless the {@link org.reactivestreams.Subscription} is
 	 * {@link Subscription#cancel() canceled}.
-	 * <p/>
+	 * <br />
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
 	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
-	 * <p/>
+	 * <br />
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
@@ -1488,10 +1517,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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 />
+	 * <br />
 	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
 	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
-	 * <p />
+	 * <br />
 	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
 	 * for resuming change streams.
 	 *
@@ -1512,10 +1541,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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 />
+	 * <br />
 	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
 	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
-	 * <p />
+	 * <br />
 	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
 	 * for resuming change streams.
 	 *
@@ -1537,10 +1566,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * 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 />
+	 * <br />
 	 * The {@link ChangeStreamEvent#getBody()} is mapped to the {@literal resultType} while the
 	 * {@link ChangeStreamEvent#getRaw()} contains the unmodified payload.
-	 * <p />
+	 * <br />
 	 * Use {@link ChangeStreamOptions} to set arguments like {@link ChangeStreamOptions#getResumeToken() the resumseToken}
 	 * for resuming change streams.
 	 *

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

@@ -41,10 +41,6 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 		this.tempate = tempate;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveRemoveOperation#remove(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveRemove<T> remove(Class<T> domainType) {
 
@@ -68,10 +64,6 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 			this.collection = collection;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveRemoveOperation.RemoveWithCollection#inCollection(String)
-		 */
 		@Override
 		public RemoveWithQuery<T> inCollection(String collection) {
 
@@ -80,10 +72,6 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 			return new ReactiveRemoveSupport<>(template, domainType, query, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveRemoveOperation.RemoveWithQuery#matching(org.springframework.data.mongodb.core.Query)
-		 */
 		@Override
 		public TerminatingRemove<T> matching(Query query) {
 
@@ -92,10 +80,6 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 			return new ReactiveRemoveSupport<>(template, domainType, query, collection);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveRemoveOperation.TerminatingRemove#all()
-		 */
 		@Override
 		public Mono<DeleteResult> all() {
 
@@ -104,10 +88,6 @@ class ReactiveRemoveOperationSupport implements ReactiveRemoveOperation {
 			return template.doRemove(collectionName, query, domainType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveRemoveOperation.TerminatingRemove#findAndRemove()
-		 */
 		@Override
 		public Flux<T> findAndRemove() {
 

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

@@ -32,7 +32,7 @@ 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 />
+	 * <br />
 	 * 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

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

@@ -33,7 +33,7 @@ public interface ReactiveSessionScoped {
 
 	/**
 	 * Executes the given {@link ReactiveSessionCallback} within the {@link com.mongodb.session.ClientSession}.
-	 * <p/>
+	 * <br />
 	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
 	 * closed} when done.
 	 *
@@ -47,7 +47,7 @@ public interface ReactiveSessionScoped {
 
 	/**
 	 * Executes the given {@link ReactiveSessionCallback} within the {@link com.mongodb.session.ClientSession}.
-	 * <p/>
+	 * <br />
 	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
 	 * closed} when done.
 	 *

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

@@ -42,10 +42,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 		this.template = template;
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation#update(java.lang.Class)
-	 */
 	@Override
 	public <T> ReactiveUpdate<T> update(Class<T> domainType) {
 
@@ -83,10 +79,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 			this.targetType = targetType;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithUpdate#apply(org.springframework.data.mongodb.core.query.UpdateDefinition)
-		 */
 		@Override
 		public TerminatingUpdate<T> apply(org.springframework.data.mongodb.core.query.UpdateDefinition update) {
 
@@ -96,10 +88,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithCollection#inCollection(java.lang.String)
-		 */
 		@Override
 		public UpdateWithQuery<T> inCollection(String collection) {
 
@@ -109,28 +97,16 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.TerminatingUpdate#first()
-		 */
 		@Override
 		public Mono<UpdateResult> first() {
 			return doUpdate(false, false);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.TerminatingUpdate#upsert()
-		 */
 		@Override
 		public Mono<UpdateResult> upsert() {
 			return doUpdate(true, true);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.TerminatingFindAndModify#findAndModify()
-		 */
 		@Override
 		public Mono<T> findAndModify() {
 
@@ -141,10 +117,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					collectionName);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.TerminatingFindAndReplace#findAndReplace()
-		 */
 		@Override
 		public Mono<T> findAndReplace() {
 			return template.findAndReplace(query, replacement,
@@ -152,10 +124,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					getCollectionName(), targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithQuery#matching(org.springframework.data.mongodb.core.Query)
-		 */
 		@Override
 		public UpdateWithUpdate<T> matching(Query query) {
 
@@ -165,19 +133,11 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.TerminatingUpdate#all()
-		 */
 		@Override
 		public Mono<UpdateResult> all() {
 			return doUpdate(true, false);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.FindAndModifyWithOptions#withOptions(org.springframework.data.mongodb.core.FindAndModifyOptions)
-		 */
 		@Override
 		public TerminatingFindAndModify<T> withOptions(FindAndModifyOptions options) {
 
@@ -187,10 +147,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.UpdateWithUpdate#replaceWith(java.lang.Object)
-		 */
 		@Override
 		public FindAndReplaceWithProjection<T> replaceWith(T replacement) {
 
@@ -200,10 +156,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					findAndReplaceOptions, replacement, targetType);
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mongodb.core.ReactiveUpdateOperation.FindAndReplaceWithOptions#withOptions(org.springframework.data.mongodb.core.FindAndReplaceOptions)
-		 */
 		@Override
 		public FindAndReplaceWithProjection<T> withOptions(FindAndReplaceOptions options) {
 
@@ -213,10 +165,6 @@ class ReactiveUpdateOperationSupport implements ReactiveUpdateOperation {
 					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) {
 

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

@@ -23,7 +23,7 @@ import org.springframework.lang.Nullable;
 
 
 /**
- * Script operations on {@link com.mongodb.DB} level. Allows interaction with server side JavaScript functions.
+ * Script operations on {@link com.mongodb.client.MongoDatabase} level. Allows interaction with server side JavaScript functions.
  *
  * @author Christoph Strobl
  * @author Oliver Gierke
@@ -72,10 +72,10 @@ public interface ScriptOperations {
 	Object call(String scriptName, Object... args);
 
 	/**
-	 * Checks {@link DB} for existence of {@link ServerSideJavaScript} with given name.
+	 * Checks {@link com.mongodb.client.MongoDatabase} for existence of {@literal ServerSideJavaScript} with given name.
 	 *
 	 * @param scriptName must not be {@literal null} or empty.
-	 * @return false if no {@link ServerSideJavaScript} with given name exists.
+	 * @return false if no {@literal ServerSideJavaScript} with given name exists.
 	 */
 	boolean exists(String scriptName);
 

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

@@ -31,7 +31,7 @@ public interface SessionCallback<T> {
 	/**
 	 * Execute operations against a MongoDB instance via session bound {@link MongoOperations}. The session is inferred
 	 * directly into the operation so that no further interaction is necessary.
-	 * <p />
+	 * <br />
 	 * Please note that only Spring Data-specific abstractions like {@link MongoOperations#find(Query, Class)} and others
 	 * are enhanced with the {@link com.mongodb.session.ClientSession}. When obtaining plain MongoDB gateway objects like
 	 * {@link com.mongodb.client.MongoCollection} or {@link com.mongodb.client.MongoDatabase} via eg.

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

@@ -23,7 +23,7 @@ import com.mongodb.client.ClientSession;
 
 /**
  * Gateway interface to execute {@link ClientSession} bound operations against MongoDB via a {@link SessionCallback}.
- * <p />
+ * <br />
  * The very same bound {@link ClientSession} is used for all invocations of {@code execute} on the instance.
  *
  * @author Christoph Strobl
@@ -34,7 +34,7 @@ public interface SessionScoped {
 
 	/**
 	 * Executes the given {@link SessionCallback} within the {@link com.mongodb.session.ClientSession}.
-	 * <p/>
+	 * <br />
 	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
 	 * closed} when done.
 	 *
@@ -49,7 +49,7 @@ public interface SessionScoped {
 
 	/**
 	 * Executes the given {@link SessionCallback} within the {@link com.mongodb.session.ClientSession}.
-	 * <p/>
+	 * <br />
 	 * It is up to the caller to make sure the {@link com.mongodb.session.ClientSession} is {@link ClientSession#close()
 	 * closed} when done.
 	 *

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

@@ -75,28 +75,16 @@ public class SimpleMongoClientDatabaseFactory extends MongoDatabaseFactorySuppor
 		super(mongoClient, databaseName, mongoInstanceCreated, new MongoExceptionTranslator());
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.MongoDbFactory#getSession(com.mongodb.ClientSessionOptions)
-	 */
 	@Override
 	public ClientSession getSession(ClientSessionOptions options) {
 		return getMongoClient().startSession(options);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.MongoDbFactoryBase#closeClient()
-	 */
 	@Override
 	protected void closeClient() {
 		getMongoClient().close();
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.MongoDbFactoryBase#doGetMongoDatabase(java.lang.String)
-	 */
 	@Override
 	protected MongoDatabase doGetMongoDatabase(String dbName) {
 		return getMongoClient().getDatabase(dbName);