Release version 6.2.0-M1 (2026.1.0).

See #3296

.github/actions/release-train-build/action.yml

@@ -0,0 +1,30 @@
+name: Build Release
+runs:
+  using: composite
+  steps:
+    - name: Write settings.xml
+      if: ${{ env.RELEASE_TRAIN_SETTINGS_XML != '' }}
+      shell: bash
+      run: |
+        echo "::notice::Writing provided settings-xml input to release-train-settings.xml"
+        echo "${RELEASE_TRAIN_SETTINGS_XML}" > release-train-settings.xml
+    - name: Prepare Maven command
+      shell: bash
+      run: |
+        MAVEN_LOGGING_OPTS=()
+        if [[ "${RUNNER_DEBUG}" == "1" || "${ACTIONS_STEP_DEBUG}" == "true" ]]; then
+          echo "::notice::transfer-progress enabled"
+        else
+          MAVEN_LOGGING_OPTS+=(--no-transfer-progress)
+        fi
+
+        echo "RELEASE_TRAIN_MVN=./mvnw --batch-mode ${MAVEN_LOGGING_OPTS[*]} --settings release-train-settings.xml clean deploy -DaltDeploymentRepository=release-train::file://$(pwd)/deployment-repository -DskipTests -Dgpg.skip" >> "${GITHUB_ENV}"
+    - name: Build Release
+      shell: bash
+      run: ${RELEASE_TRAIN_MVN} --activate-profiles releaseTrain,release,ci
+    - name: Distribution build
+      shell: bash
+      run: ${RELEASE_TRAIN_MVN} --activate-profiles releaseTrain,distribute
+    - name: Schema build
+      shell: bash
+      run: ${RELEASE_TRAIN_MVN} --activate-profiles releaseTrain,distribute-schema

.github/actions/release-train-build/deployment-spec.yml

@@ -0,0 +1,6 @@
+artifactory:
+  artifacts:
+    - pattern: "/**/spring-data-*-docs.zip"
+      properties:
+        zip.deployed: "false"
+        zip.type: "docs"

.github/actions/release-train-test/action.yml

@@ -0,0 +1,24 @@
+name: Test Release
+runs:
+  using: composite
+  steps:
+    - name: Write settings.xml
+      if: ${{ env.RELEASE_TRAIN_SETTINGS_XML != '' }}
+      shell: bash
+      run: |
+        echo "::notice::Writing provided settings-xml input to release-train-settings.xml"
+        echo "${RELEASE_TRAIN_SETTINGS_XML}" > release-train-settings.xml
+    - name: Prepare Maven command
+      shell: bash
+      run: |
+        MAVEN_LOGGING_OPTS=()
+        if [[ "${RUNNER_DEBUG}" == "1" || "${ACTIONS_STEP_DEBUG}" == "true" ]]; then
+          echo "::notice::transfer-progress enabled"
+        else
+          MAVEN_LOGGING_OPTS+=(--no-transfer-progress)
+        fi
+
+        echo "RELEASE_TRAIN_MVN=./mvnw --batch-mode ${MAVEN_LOGGING_OPTS[*]} --settings release-train-settings.xml clean verify -Dgpg.skip" >> "${GITHUB_ENV}"
+    - name: Test Release
+      shell: bash
+      run: ${RELEASE_TRAIN_MVN} --activate-profiles releaseTrain,release,ci

.github/workflow-generator.yml

@@ -0,0 +1,26 @@
+workflow:
+  generator:
+    project:
+      java:
+        versions:
+          primary: 25
+    workflows:
+      release-train:
+        join:
+          watch: false
+        leave:
+          watch: false
+        ready:
+          watch: false
+        build:
+          env:
+            COMMERCIAL_REPO_USERNAME: secrets.COMMERCIAL_ARTIFACTORY_USERNAME
+            COMMERCIAL_REPO_PASSWORD: secrets.COMMERCIAL_ARTIFACTORY_PASSWORD
+            COMMERCIAL_RELEASE_REPO_URL: vars.COMMERCIAL_RELEASE_REPO_URL
+            RELEASE_TRAIN_SETTINGS_XML: vars.RELEASE_TRAIN_SETTINGS_XML
+        test:
+          env:
+            COMMERCIAL_REPO_USERNAME: secrets.COMMERCIAL_ARTIFACTORY_USERNAME
+            COMMERCIAL_REPO_PASSWORD: secrets.COMMERCIAL_ARTIFACTORY_PASSWORD
+            COMMERCIAL_RELEASE_REPO_URL: vars.COMMERCIAL_RELEASE_REPO_URL
+            RELEASE_TRAIN_SETTINGS_XML: vars.RELEASE_TRAIN_SETTINGS_XML

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         java-version: [ base, main ]
     name: Build project
-    runs-on: ubuntu-latest
+    runs-on: ${{ vars.ACTION_RUNNER || 'ubuntu-latest' }}
     steps:
       - uses: actions/checkout@v6
       - name: Setup Java and Maven
@@ -24,4 +24,10 @@ jobs:
       - name: Build
         uses: spring-projects/spring-data-build/actions/maven-build@main
         env:
+          OSS_ARTIFACTORY_USR: '${{ secrets.ARTIFACTORY_USERNAME }}'
+          OSS_ARTIFACTORY_PSW: '${{ secrets.ARTIFACTORY_PASSWORD }}'
+          COMMERCIAL_ARTIFACTORY_USR: '${{ secrets.COMMERCIAL_ARTIFACTORY_USERNAME }}'
+          COMMERCIAL_ARTIFACTORY_PSW: '${{ secrets.COMMERCIAL_ARTIFACTORY_PASSWORD }}'
           TESTCONTAINERS_REUSE_ENABLE: true
+        with:
+          settings-xml: '${{ vars.SETTINGS_XML }}'

.github/workflows/codeql.yml

@@ -4,6 +4,7 @@ name: "CodeQL Advanced"
 
 on:
   push:
+    branches: [ main ]
   pull_request:
   workflow_dispatch:
   schedule:

.github/workflows/release-train-build.yml

@@ -0,0 +1,92 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Build"
+run-name: "${{ inputs.callback-ref }} – Build"
+"on":
+  workflow_dispatch:
+    inputs:
+      callback:
+        description: "Repository to which a callback should be made upon completion"
+        required: true
+        type: "string"
+      callback-ref:
+        description: "Ref in the callback repository to which a callback should be made upon completion"
+        required: true
+        type: "string"
+      release-train-maven-repository-url:
+        description: "URL of a Maven repository to be used to resolve artifacts of projects earlier in the train"
+        required: true
+        type: "string"
+permissions:
+  contents: "read"
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+jobs:
+  build-release:
+    name: "Build Release"
+    runs-on: "ubuntu22-2-8"
+    steps:
+    - name: "Prevent Re-runs"
+      id: "prevent-re-runs"
+      run: |-
+        if [ "$GITHUB_RUN_ATTEMPT" -gt 1 ]; then
+          echo "Re-runs are prohibited. Use the 'Release Train – Retry' workflow to retry build failures"
+          exit 1
+        fi
+    - name: "Set up Java"
+      id: "set-up-java"
+      uses: "actions/setup-java@03ad4de0992f5dab5e18fcb136590ce7c4a0ac95" # v5.6.0
+      with:
+        distribution: "liberica"
+        java-version: "25"
+    - name: "Check Out Code"
+      id: "check-out-code"
+      uses: "actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0" # v7.0.0
+    - name: "Build Release"
+      id: "build-release"
+      uses: "./.github/actions/release-train-build"
+      env:
+        COMMERCIAL_RELEASE_REPO_URL: "${{ vars.COMMERCIAL_RELEASE_REPO_URL }}"
+        COMMERCIAL_REPO_PASSWORD: "${{ secrets.COMMERCIAL_ARTIFACTORY_PASSWORD }}"
+        COMMERCIAL_REPO_USERNAME: "${{ secrets.COMMERCIAL_ARTIFACTORY_USERNAME }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_PASSWORD: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_MAVEN_REPOSITORY_PASSWORD }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_URL: "${{ inputs.release-train-maven-repository-url }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_USERNAME: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_MAVEN_REPOSITORY_USERNAME }}"
+        RELEASE_TRAIN_SETTINGS_XML: "${{ vars.RELEASE_TRAIN_SETTINGS_XML }}"
+    - name: "Upload Deployment Repository"
+      id: "upload-deployment-repository"
+      uses: "actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a" # v7.0.1
+      with:
+        name: "deployment-repository"
+        path: "deployment-repository/**"
+    - name: "Upload Deployment Spec"
+      id: "upload-deployment-spec"
+      uses: "actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a" # v7.0.1
+      with:
+        archive: "false"
+        if-no-files-found: "ignore"
+        name: "deployment-spec"
+        path: ".github/actions/release-train-build/deployment-spec.yml"
+    - name: "Save Build System Caches"
+      id: "save-build-system-caches"
+      uses: "actions/cache/save@55cc8345863c7cc4c66a329aec7e433d2d1c52a9" # v6.1.0
+      with:
+        key: "release-train-${{ inputs.callback-ref }}-${{ github.ref_name }}"
+        path: "~/.m2/repository"
+    - name: "Send Callback"
+      id: "send-callback"
+      if: "${{ !cancelled() }}"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run callback \
+        --repo ${{ inputs.callback }} \
+        --ref ${{ inputs.callback-ref }} \
+        --field commit-hash=${{ steps.check-out-code.outputs.commit }} \
+        --field deployment-repository-artifact-identifier=${{ steps.upload-deployment-repository.outputs.artifact-id }} \
+        --field deployment-spec-artifact-identifier=${{ steps.upload-deployment-spec.outputs.artifact-id }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }} \
+        --field result=${{ job.status == 'success' && 'built' || 'build-failed' }} \
+        --field workflow-run-url=${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}

.github/workflows/release-train-join.yml

@@ -0,0 +1,43 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Join"
+run-name: "${{ inputs.release-train }} – Join"
+"on":
+  workflow_dispatch:
+    inputs:
+      deployment-destination:
+        description: "Destination to which the release should be deployed"
+        options:
+        - "Maven Central"
+        - "Spring Enterprise"
+        required: true
+        type: "choice"
+      release-train:
+        description: "Release train"
+        required: true
+        type: "string"
+      release-train-repository:
+        default: "spring-io/release-train"
+        description: "Release train repository"
+        required: true
+        type: "string"
+permissions:
+  contents: "none"
+jobs:
+  join-release-train:
+    name: "Join Release Train"
+    runs-on: "ubuntu-latest"
+    steps:
+    - name: "Join Release Train"
+      id: "join-release-train"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run join \
+        --repo ${{ inputs.release-train-repository }} \
+        --ref ${{ inputs.release-train }} \
+        --field commit-hash=${{ github.sha }} \
+        --field deployment-destination=${{ inputs.deployment-destination == 'Maven Central' && 'maven-central' || 'spring-enterprise' }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }}

.github/workflows/release-train-leave.yml

@@ -0,0 +1,34 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Leave"
+run-name: "${{ inputs.release-train }} – Leave"
+"on":
+  workflow_dispatch:
+    inputs:
+      release-train:
+        description: "Release train"
+        required: true
+        type: "string"
+      release-train-repository:
+        default: "spring-io/release-train"
+        description: "Release train repository"
+        required: true
+        type: "string"
+permissions:
+  contents: "none"
+jobs:
+  leave:
+    name: "Leave"
+    runs-on: "ubuntu-latest"
+    steps:
+    - name: "Leave"
+      id: "leave"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run leave \
+        --repo ${{ inputs.release-train-repository }} \
+        --ref ${{ inputs.release-train }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }}

.github/workflows/release-train-ready.yml

@@ -0,0 +1,35 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Ready"
+run-name: "${{ inputs.release-train }} – Ready"
+"on":
+  workflow_dispatch:
+    inputs:
+      release-train:
+        description: "Release train"
+        required: true
+        type: "string"
+      release-train-repository:
+        default: "spring-io/release-train"
+        description: "Release train repository"
+        required: true
+        type: "string"
+permissions:
+  contents: "none"
+jobs:
+  ready:
+    name: "Ready"
+    runs-on: "ubuntu-latest"
+    steps:
+    - name: "Ready"
+      id: "ready"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run ready \
+        --repo ${{ inputs.release-train-repository }} \
+        --ref ${{ inputs.release-train }} \
+        --field commit-hash=${{ github.sha }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }}

.github/workflows/release-train-retry.yml

@@ -0,0 +1,34 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Retry"
+run-name: "${{ inputs.release-train }} – Retry"
+"on":
+  workflow_dispatch:
+    inputs:
+      release-train:
+        description: "Release train"
+        required: true
+        type: "string"
+      release-train-repository:
+        default: "spring-io/release-train"
+        description: "Release train repository"
+        required: true
+        type: "string"
+permissions:
+  contents: "none"
+jobs:
+  trigger-retry:
+    name: "Trigger Retry"
+    runs-on: "ubuntu-latest"
+    steps:
+    - name: "Trigger Retry"
+      id: "trigger-retry"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run retry \
+        --repo ${{ inputs.release-train-repository }} \
+        --ref ${{ inputs.release-train }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }}

.github/workflows/release-train-test.yml

@@ -0,0 +1,85 @@
+# This file was auto-generated by github-actions-workflow-generator 0.0.6. Do not edit.
+# To update it, modify .github/workflow-generator.yml as needed and re-run the generator.
+
+name: "Release Train – Test"
+run-name: "${{ inputs.callback-ref }} – Test"
+"on":
+  workflow_dispatch:
+    inputs:
+      callback:
+        description: "Repository to which a callback should be made upon completion"
+        required: true
+        type: "string"
+      callback-ref:
+        description: "Ref in the callback repository to which a callback should be made upon completion"
+        required: true
+        type: "string"
+      release-train-maven-repository-url:
+        description: "URL of a Maven repository to be used to resolve artifacts of projects earlier in the train"
+        required: true
+        type: "string"
+permissions:
+  contents: "read"
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+jobs:
+  test-release:
+    name: "Test Release"
+    runs-on: "ubuntu22-2-8"
+    steps:
+    - name: "Prevent Re-runs"
+      id: "prevent-re-runs"
+      run: |-
+        if [ "$GITHUB_RUN_ATTEMPT" -gt 1 ]; then
+          echo "Re-runs are prohibited. Use the 'Release Train – Retry' workflow to retry test failures"
+          exit 1
+        fi
+    - name: "Set up Java"
+      id: "set-up-java"
+      uses: "actions/setup-java@03ad4de0992f5dab5e18fcb136590ce7c4a0ac95" # v5.6.0
+      with:
+        distribution: "liberica"
+        java-version: "25"
+    - name: "Check Out Code"
+      id: "check-out-code"
+      uses: "actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0" # v7.0.0
+    - name: "Restore Build System Caches"
+      id: "restore-build-system-caches"
+      uses: "actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9" # v6.1.0
+      with:
+        key: "release-train-${{ inputs.callback-ref }}-${{ github.ref_name }}"
+        path: "~/.m2/repository"
+    - name: "Test Release"
+      id: "test-release"
+      uses: "./.github/actions/release-train-test"
+      env:
+        COMMERCIAL_RELEASE_REPO_URL: "${{ vars.COMMERCIAL_RELEASE_REPO_URL }}"
+        COMMERCIAL_REPO_PASSWORD: "${{ secrets.COMMERCIAL_ARTIFACTORY_PASSWORD }}"
+        COMMERCIAL_REPO_USERNAME: "${{ secrets.COMMERCIAL_ARTIFACTORY_USERNAME }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_PASSWORD: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_MAVEN_REPOSITORY_PASSWORD }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_URL: "${{ inputs.release-train-maven-repository-url }}"
+        RELEASE_TRAIN_MAVEN_REPOSITORY_USERNAME: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_MAVEN_REPOSITORY_USERNAME }}"
+        RELEASE_TRAIN_SETTINGS_XML: "${{ vars.RELEASE_TRAIN_SETTINGS_XML }}"
+    - name: "Send Callback"
+      id: "send-callback"
+      if: "${{ !cancelled() }}"
+      env:
+        GH_TOKEN: "${{ secrets.RELEASE_TRAIN_PARTICIPANT_GITHUB_TOKEN }}"
+      run: |-
+        gh workflow run callback \
+        --repo ${{ inputs.callback }} \
+        --ref ${{ inputs.callback-ref }} \
+        --field commit-hash=${{ steps.check-out-code.outputs.commit }} \
+        --field release-branch=${{ github.ref_name }} \
+        --field release-repository=${{ github.repository }} \
+        --field result=${{ job.status == 'success' && 'tested' || 'test-failed' }} \
+        --field workflow-run-url=${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+    - name: "Upload Build System Reports"
+      id: "upload-build-system-reports"
+      if: "${{ failure() }}"
+      uses: "actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a" # v7.0.1
+      with:
+        name: "build-system-reports"
+        path: |-
+          **/target/surefire-reports
+          **/target/failsafe-reports

.github/workflows/snapshots.yml

@@ -3,7 +3,7 @@ name: Snapshots
 on:
   workflow_dispatch:
   push:
-    branches: [ main, 'issue/**' ]
+    branches: [ main, 'issue/**', 'release/**' ]
 
 permissions: read-all
 
@@ -11,7 +11,7 @@ jobs:
   build-snapshots:
     name: Build and deploy snapshots
     if: ${{ github.repository_owner == 'spring-projects' }}
-    runs-on: ubuntu-latest
+    runs-on: ${{ vars.ACTION_RUNNER || 'ubuntu-latest' }}
     steps:
       - uses: actions/checkout@v6
       - name: Setup Java and Maven
@@ -21,8 +21,11 @@ jobs:
       - name: Deploy to Artifactory
         uses: spring-projects/spring-data-build/actions/maven-artifactory-deploy@main
         env:
+          OSS_ARTIFACTORY_USR: '${{ secrets.ARTIFACTORY_USERNAME }}'
+          OSS_ARTIFACTORY_PSW: '${{ secrets.ARTIFACTORY_PASSWORD }}'
+          COMMERCIAL_ARTIFACTORY_USR: '${{ secrets.COMMERCIAL_ARTIFACTORY_USERNAME }}'
+          COMMERCIAL_ARTIFACTORY_PSW: '${{ secrets.COMMERCIAL_ARTIFACTORY_PASSWORD }}'
           TESTCONTAINERS_REUSE_ENABLE: true
         with:
           build-name: 'spring-data-elasticsearch'
-          username: '${{ secrets.ARTIFACTORY_USERNAME }}'
-          password: '${{ secrets.ARTIFACTORY_PASSWORD }}'
+          settings-xml: '${{ vars.SETTINGS_XML }}'

.mvn/wrapper/maven-wrapper.properties

@@ -1,3 +1,3 @@
-#Thu Jul 17 13:59:56 CEST 2025
+#Tue Jun 02 14:58:35 CEST 2026
+distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.16/apache-maven-3.9.16-bin.zip
 wrapperUrl=https\://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar
-distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.11/apache-maven-3.9.11-bin.zip

SECURITY.adoc

@@ -1,15 +0,0 @@
-= Security Policy
-
-== Reporting a Vulnerability
-
-Please, https://github.com/spring-projects/security-advisories/security/advisories/new[open a draft security advisory] if you need to disclose and discuss a security issue in private with the Spring Data team.
-Note that we only accept reports against https://spring.io/projects/spring-data#support[supported versions].
-
-For more details, check out our https://spring.io/security-policy[security policy].
-
-== JAR signing
-
-Spring Data JARs released on Maven Central are signed.
-You'll find more information about the key here: https://spring.io/GPG-KEY-spring.txt
-
-Versions released prior to 2023 may be signed with a different key.

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+Please [open a draft security advisory](https://github.com/spring-projects/spring-data-elasticsearch/security/advisories/new) if you need to disclose and discuss a security issue in private with the Spring Data team.
+Note that we only accept reports against [supported versions](https://spring.io/projects/spring-data#support).
+
+For more details, check out our [security policy](https://spring.io/security-policy).
+
+## JAR signing
+
+Spring Data JARs released on Maven Central are signed.
+You'll find more information about the key here: https://spring.io/GPG-KEY-spring.txt
+
+Versions released prior to 2023 may be signed with a different key.

SUPPORT.adoc

@@ -0,0 +1,11 @@
+= Getting support for Spring Data Elasticsearch
+
+Spring Data Elasticsearch is a community-maintained Spring Data project. It is released as part of the Spring Data Release train.
+
+== GitHub issues
+
+We choose not to use GitHub issues for general usage questions and support, preferring to use issues solely for the tracking of bugs and enhancements.
+If you have a general usage question, please do not open a GitHub issue but use one of the other channels https://github.com/spring-projects/spring-data-elasticsearch#getting-help[described in the readme file].
+
+If you are reporting a bug, please help to speed up problem diagnosis by providing as much information as possible.
+Ideally, that would include a small sample project that reproduces the problem.

pom.xml

@@ -5,12 +5,12 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-elasticsearch</artifactId>
-	<version>6.1.0-M2</version>
+	<version>6.2.0-M1</version>
 
 	<parent>
 		<groupId>org.springframework.data.build</groupId>
 		<artifactId>spring-data-parent</artifactId>
-		<version>4.1.0-M2</version>
+		<version>4.2.0-M1</version>
 	</parent>
 
 	<name>Spring Data Elasticsearch</name>
@@ -18,14 +18,14 @@
 	<url>https://github.com/spring-projects/spring-data-elasticsearch</url>
 
 	<properties>
-		<springdata.commons>4.1.0-M2</springdata.commons>
+		<springdata.commons>4.2.0-M1</springdata.commons>
 
 		<!-- version of the ElasticsearchClient	-->
-		<elasticsearch-java>9.3.1</elasticsearch-java>
-		<elasticsearch-rest-client>9.3.1</elasticsearch-rest-client>
+		<elasticsearch-java>9.5.0</elasticsearch-java>
+		<elasticsearch-rest-client>9.5.0</elasticsearch-rest-client>
 
 		<hoverfly>0.20.2</hoverfly>
-		<log4j>2.25.3</log4j>
+		<log4j>2.25.4</log4j>
 		<jsonassert>1.5.3</jsonassert>
 		<wiremock>3.9.2</wiremock>
 
@@ -82,8 +82,7 @@
 	<scm>
 		<url>https://github.com/spring-projects/spring-data-elasticsearch</url>
 		<connection>scm:git:git://github.com/spring-projects/spring-data-elasticsearch.git</connection>
-		<developerConnection>scm:git:ssh://git@github.com/spring-projects/spring-data-elasticsearch.git
-		</developerConnection>
+		<developerConnection>scm:git:ssh://git@github.com/spring-projects/spring-data-elasticsearch.git</developerConnection>
 	</scm>
 
 	<issueManagement>
@@ -377,8 +376,18 @@
 				<filtering>false</filtering>
 				<excludes>
 					<exclude>**/versions.properties</exclude>
+					<exclude>notice.txt</exclude>
+					<exclude>license.txt</exclude>
 				</excludes>
 			</resource>
+			<resource>
+				<directory>${project.root}/src/main/resources</directory>
+				<targetPath>META-INF</targetPath>
+				<includes>
+					<include>notice.txt</include>
+					<include>license.txt</include>
+				</includes>
+			</resource>
 		</resources>
 
 		<plugins>

settings.xml

@@ -1,29 +0,0 @@
-<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>

src/main/antora/modules/ROOT/pages/elasticsearch/clients.adoc

@@ -3,7 +3,7 @@
 
 This chapter illustrates configuration and usage of supported Elasticsearch client implementations.
 
-Spring Data Elasticsearch operates upon an Elasticsearch client (provided by Elasticsearch client libraries) that is connected to a single Elasticsearch node or a cluster.
+Spring Data Elasticsearch operates upon an Elasticsearch client (provided by Elasticsearch client libraries) that is connected to a single Elasticsearch node, a cluster or Elasticsearch serverless.
 Although the Elasticsearch Client can be used directly to work with the cluster, applications using Spring Data Elasticsearch normally use the higher level abstractions of xref:elasticsearch/template.adoc[Elasticsearch Operations] and xref:elasticsearch/repositories/elasticsearch-repositories.adoc[Elasticsearch Repositories].
 
 [[elasticsearch.clients.rest5client]]
@@ -454,6 +454,22 @@ ClientConfiguration.builder()
 ----
 ====
 
+[[elasticsearch.clients.servertype]]
+== Server Type
+There are now 2 types of server that a client could connect to. They are `DEFAULT` which represent all single nodes and clusters; and `SERVERLESS` which represents Elasticsearch new flavour of providing cloud hosted elasticsearch.
+If you are going to use Elasticsearch Serverless then you need to specific this so that certain settings are changed and indexes are created correctly.
+The javadoc:org.springframework.data.elasticsearch.config.ElasticsearchConfigurationSupport[] class (extended by javadoc:org.springframework.data.elasticsearch.client.elc.ElasticsearchConfiguration[]) allows the overriding of `serverType()`.
+
+====
+[source,java]
+----
+@Override
+ElasticsearchServerType serverType() {
+  return ElasticsearchServerType.SERVERLESS;
+}
+----
+====
+
 [[elasticsearch.clients.logging]]
 == Client Logging
 

src/main/antora/modules/ROOT/pages/elasticsearch/elasticsearch-new.adoc

@@ -1,10 +1,18 @@
 [[new-features]]
 = What's new
 
+[[new-features.6-2-0]]
+== New in Spring Data Elasticsearch 6.2
+
+* Upgrade to Elasticsearch 9.5.0
+* Allow to provide non-standard (custom) index options for `@Field` / `@InnerField`
+* Support Elasticsearch Serverless
+* Support propert resolution in index name expressions (https://github.com/spring-projects/spring-data-elasticsearch/issues/3310[GH #3310])
+
 [[new-features.6-1-0]]
 == New in Spring Data Elasticsearch 6.1
 
-* Upgrade to Elasticsearch 9.3.1
+* Upgrade to Elasticsearch 9.4.2
 * Add support to use `IndexCoordinates` as repository query parameter
 * Add support for includeNamedQueriesScore in Query
 * Add support for Micrometer observation.

src/main/antora/modules/ROOT/pages/elasticsearch/object-mapping.adoc

@@ -22,7 +22,7 @@ The following annotations are available:
 * `@Document`: Applied at the class level to indicate this class is a candidate for mapping to the database.
 The most important attributes are (check the API documentation for the complete list of attributes):
 ** `indexName`: the name of the index to store this entity in.
-This can contain a SpEL template expression like `"log-#{T(java.time.LocalDate).now().toString()}"`
+This can contain a SpEL template expression like `"log-#{T(java.time.LocalDate).now().toString()}"` or a property expression like `{index.name}`
 ** `createIndex`: flag whether to create an index on repository bootstrapping.
 Default value is _true_.
 See xref:elasticsearch/repositories/elasticsearch-repositories.adoc#elasticsearch.repositories.autocreation[Automatic creation of indices with the corresponding mapping]

src/main/antora/modules/ROOT/pages/elasticsearch/versions.adoc

@@ -6,10 +6,11 @@ The following table shows the Elasticsearch and Spring versions that are used by
 [cols="^,^,^,^",options="header"]
 |===
 | Spring Data Release Train | Spring Data Elasticsearch | Elasticsearch | Spring Framework
-| 2026.0 | 6.1.x | 9.3.1 | 7.0.x
+| 2026.1 | 6.2.x | 9.5.0 | 7.0.x
+| 2026.0 | 6.1.x | 9.4.2 | 7.0.x
 | 2025.1 | 6.0.x | 9.2.2 | 7.0.x
-| 2025.0 | 5.5.x | 8.18.1 | 6.2.x
-| 2024.1 | 5.4.xfootnote:oom[Out of maintenance] | 8.15.5 | 6.1.x
+| 2025.0 | 5.5.xfootnote:oom[Out of maintenance] | 8.18.1 | 6.2.x
+| 2024.1 | 5.4.xfootnote:oom[] | 8.15.5 | 6.1.x
 | 2024.0 | 5.3.xfootnote:oom[] | 8.13.4 | 6.1.x
 | 2023.1 (Vaughan) | 5.2.xfootnote:oom[] | 8.11.1 | 6.1.x
 | 2023.0 (Ullmann) | 5.1.xfootnote:oom[] | 8.7.1 | 6.0.x

src/main/antora/modules/ROOT/pages/repositories/projections.adoc

@@ -1,4 +1,13 @@
 [[elasticsearch.projections]]
 = Projections
 
+[[elasticsearch.projections.limitations]]
+== Spring Data Elasticsearch Projection Limitations
+
+This chapter is pulled in from the Spring Data Commons documentation, but does not apply to Spring Data Elasticsearch.
+
+IMPORTANT: Interface-based projections are not supported in Spring Data Elasticsearch repository query methods.
+
+To limit the fields returned from Elasticsearch, use the xref:elasticsearch/repositories/elasticsearch-repositories.adoc#elasticsearch.repositories.annotations.sourcefilters[`@SourceFilters`] annotation on your repository methods instead.
+
 include::{commons}@data-commons::page$repositories/projections.adoc[leveloffset=+1]

src/main/antora/resources/antora-resources/antora.yml

@@ -13,7 +13,7 @@ asciidoc:
     include-xml-namespaces: false
     spring-data-commons-docs-url: '${documentation.baseurl}/spring-data/commons/reference/${springdata.commons.short}'
     spring-data-commons-javadoc-base: '{spring-data-commons-docs-url}/api/java'
-    springdocsurl: '${documentation.baseurl}/spring-framework/reference/{springversionshort}'
+    springdocsurl: '${documentation.spring-reference-url}/{springversionshort}'
     spring-framework-docs: '{springdocsurl}'
     springjavadocurl: '${documentation.spring-javadoc-url}'
     spring-framework-javadoc: '{springjavadocurl}'

src/main/java/org/springframework/data/elasticsearch/BulkFailureException.java

@@ -15,10 +15,11 @@
  */
 package org.springframework.data.elasticsearch;
 
-import org.springframework.dao.DataRetrievalFailureException;
-
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+import org.springframework.dao.DataRetrievalFailureException;
+
 /**
  * @author Peter-Josef Meisch
  * @author Illia Ulianov
@@ -42,6 +43,6 @@ public class BulkFailureException extends DataRetrievalFailureException {
 	 * @author Illia Ulianov
 	 * @since 5.2
 	 */
-	public record FailureDetails(Integer status, String errorMessage) {
+	public record FailureDetails(Integer status, @Nullable String errorMessage) {
 	}
 }

src/main/java/org/springframework/data/elasticsearch/ElasticsearchErrorCause.java

@@ -28,7 +28,7 @@ import org.jspecify.annotations.Nullable;
 public class ElasticsearchErrorCause {
 	@Nullable private final String type;
 
-	private final String reason;
+	@Nullable private final String reason;
 
 	@Nullable private final String stackTrace;
 
@@ -38,7 +38,7 @@ public class ElasticsearchErrorCause {
 
 	private final List<ElasticsearchErrorCause> suppressed;
 
-	public ElasticsearchErrorCause(@Nullable String type, String reason, @Nullable String stackTrace,
+	public ElasticsearchErrorCause(@Nullable String type, @Nullable String reason, @Nullable String stackTrace,
 			@Nullable ElasticsearchErrorCause causedBy, List<ElasticsearchErrorCause> rootCause,
 			List<ElasticsearchErrorCause> suppressed) {
 		this.type = type;
@@ -54,7 +54,7 @@ public class ElasticsearchErrorCause {
 		return type;
 	}
 
-	public String getReason() {
+	public @Nullable String getReason() {
 		return reason;
 	}
 

src/main/java/org/springframework/data/elasticsearch/annotations/CustomIndexOption.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2026-present 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.elasticsearch.annotations;
+
+import org.springframework.data.elasticsearch.core.index.IndexOptionMapper;
+
+/**
+ * Represents the custom index option, either not provided by the core (fe, custom plugin) or deviates across different
+ * engines.
+ *
+ * @author Andriy Redko
+ * @since 6.2
+ */
+public @interface CustomIndexOption {
+	/**
+	 * The name of the custom index option
+	 */
+	String name();
+
+	/**
+	 * The value(s) of the custom index option
+	 */
+	String[] values() default {};
+
+	/**
+	 * Should the index property be overridden if already present or not
+	 */
+	boolean overrideIfPresent() default false;
+
+	/**
+	 * The index option mapper that will be used to populate this custom index option
+	 */
+	Class<? extends IndexOptionMapper> mapper();
+}

src/main/java/org/springframework/data/elasticsearch/annotations/Field.java

@@ -252,4 +252,11 @@ public @interface Field {
 	 * @since 5.4
 	 */
 	String mappedTypeName() default "";
+
+	/**
+	 * adds the custom index options for a particular field
+	 *
+	 * @since 6.2
+	 */
+	CustomIndexOption[] customIndexOptions() default {};
 }

src/main/java/org/springframework/data/elasticsearch/annotations/InnerField.java

@@ -179,4 +179,11 @@ public @interface InnerField {
 	 * @since 5.4
 	 */
 	String mappedTypeName() default "";
+
+	/**
+	 * adds the custom index options for a particular field
+	 *
+	 * @since 6.2
+	 */
+	CustomIndexOption[] customIndexOptions() default {};
 }

src/main/java/org/springframework/data/elasticsearch/annotations/Setting.java

@@ -22,12 +22,14 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 import org.springframework.data.annotation.Persistent;
+import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchPersistentEntity;
 
 /**
  * Elasticsearch Setting
  *
  * @author Mohsin Husen
  * @author Peter-Josef Meisch
+ * @author Steven Pearce
  */
 
 @Persistent
@@ -59,9 +61,10 @@ public @interface Setting {
 	short replicas() default 1;
 
 	/**
-	 * Refresh interval for the index. Used for index creation.
+	 * Refresh interval for the index. Used for index creation. If no value, defaults are server type dependant and set in
+	 * {@link SimpleElasticsearchPersistentEntity}
 	 */
-	String refreshInterval() default "1s";
+	String refreshInterval() default "";
 
 	/**
 	 * Index storage type for the index. Used for index creation.

src/main/java/org/springframework/data/elasticsearch/annotations/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.annotations;

src/main/java/org/springframework/data/elasticsearch/aot/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.aot;

src/main/java/org/springframework/data/elasticsearch/client/elc/DocumentAdapters.java

@@ -24,6 +24,20 @@ import co.elastic.clients.elasticsearch.core.search.Hit;
 import co.elastic.clients.elasticsearch.core.search.NestedIdentity;
 import co.elastic.clients.json.JsonData;
 import co.elastic.clients.json.JsonpMapper;
+import jakarta.json.JsonArray;
+import jakarta.json.JsonNumber;
+import jakarta.json.JsonObject;
+import jakarta.json.JsonString;
+import jakarta.json.JsonValue;
+
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.jspecify.annotations.Nullable;
@@ -36,13 +50,6 @@ import org.springframework.data.elasticsearch.core.document.SearchDocumentAdapte
 import org.springframework.data.elasticsearch.core.document.SearchDocumentResponse;
 import org.springframework.util.Assert;
 
-import java.util.Collections;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-
 /**
  * Utility class to adapt different Elasticsearch responses to a
  * {@link org.springframework.data.elasticsearch.core.document.Document}
@@ -54,188 +61,228 @@ import java.util.stream.Collectors;
  */
 final class DocumentAdapters {
 
-    private static final Log LOGGER = LogFactory.getLog(DocumentAdapters.class);
+	private static final Log LOGGER = LogFactory.getLog(DocumentAdapters.class);
 
-    private DocumentAdapters() {
-    }
+	private DocumentAdapters() {}
 
-    /**
-     * Creates a {@link SearchDocument} from a {@link Hit} returned by the Elasticsearch client.
-     *
-     * @param hit         the hit object
-     * @param jsonpMapper to map JsonData objects
-     * @return the created {@link SearchDocument}
-     */
-    public static SearchDocument from(Hit<?> hit, JsonpMapper jsonpMapper) {
+	/**
+	 * Creates a {@link SearchDocument} from a {@link Hit} returned by the Elasticsearch client.
+	 *
+	 * @param hit the hit object
+	 * @param jsonpMapper to map JsonData objects
+	 * @return the created {@link SearchDocument}
+	 */
+	public static SearchDocument from(Hit<?> hit, JsonpMapper jsonpMapper) {
 
-        Assert.notNull(hit, "hit must not be null");
+		Assert.notNull(hit, "hit must not be null");
 
-        Map<String, List<String>> highlightFields = hit.highlight();
+		Map<String, List<String>> highlightFields = hit.highlight();
 
-        Map<String, SearchDocumentResponse> innerHits = new LinkedHashMap<>();
-        hit.innerHits().forEach((name, innerHitsResult) -> {
-            // noinspection ReturnOfNull
-            innerHits.put(name, SearchDocumentResponseBuilder.from(innerHitsResult.hits(), null, null, null, 0, null, null,
-                    searchDocument -> null, jsonpMapper));
-        });
+		Map<String, SearchDocumentResponse> innerHits = new LinkedHashMap<>();
+		hit.innerHits().forEach((name, innerHitsResult) -> {
+			// noinspection ReturnOfNull
+			innerHits.put(name, SearchDocumentResponseBuilder.from(innerHitsResult.hits(), null, null, null, 0, null, null,
+					searchDocument -> null, jsonpMapper));
+		});
 
-        NestedMetaData nestedMetaData = from(hit.nested());
+		NestedMetaData nestedMetaData = from(hit.nested());
 
-        Explanation explanation = from(hit.explanation());
+		Explanation explanation = from(hit.explanation());
 
-        Map<String, Double> matchedQueries = hit.matchedQueries();
+		Map<String, Double> matchedQueries = hit.matchedQueries();
 
-        Function<Map<String, JsonData>, EntityAsMap> fromFields = fields -> {
-            StringBuilder sb = new StringBuilder("{");
-            final boolean[] firstField = {true};
-            hit.fields().forEach((key, jsonData) -> {
-                if (!firstField[0]) {
-                    sb.append(',');
-                }
-                sb.append('"').append(key).append("\":") //
-                        .append(jsonData.toJson(jsonpMapper).toString());
-                firstField[0] = false;
-            });
-            sb.append('}');
-            return new EntityAsMap().fromJson(sb.toString());
-        };
+		EntityAsMap hitFieldsAsMap = new EntityAsMap();
+		hit.fields().forEach((key, jsonData) -> hitFieldsAsMap.put(key, toJavaObject(jsonData, jsonpMapper)));
 
-        EntityAsMap hitFieldsAsMap = fromFields.apply(hit.fields());
+		Map<String, List<@Nullable Object>> documentFields = new LinkedHashMap<>();
+		hitFieldsAsMap.forEach((key, value) -> {
+			if (value instanceof List) {
+				// noinspection unchecked
+				documentFields.put(key, (List<Object>) value);
+			} else {
+				documentFields.put(key, Collections.singletonList(value));
+			}
+		});
 
-        Map<String, List<Object>> documentFields = new LinkedHashMap<>();
-        hitFieldsAsMap.forEach((key, value) -> {
-            if (value instanceof List) {
-                // noinspection unchecked
-                documentFields.put(key, (List<Object>) value);
-            } else {
-                documentFields.put(key, Collections.singletonList(value));
-            }
-        });
+		Document document;
+		Object source = hit.source();
+		if (source == null) {
+			document = Document.from(hitFieldsAsMap);
+		} else {
+			if (source instanceof EntityAsMap entityAsMap) {
+				document = Document.from(entityAsMap);
+			} else if (source instanceof JsonData jsonData) {
+				document = Document.from(jsonData.to(EntityAsMap.class));
+			} else {
 
-        Document document;
-        Object source = hit.source();
-        if (source == null) {
-            document = Document.from(hitFieldsAsMap);
-        } else {
-            if (source instanceof EntityAsMap entityAsMap) {
-                document = Document.from(entityAsMap);
-            } else if (source instanceof JsonData jsonData) {
-                document = Document.from(jsonData.to(EntityAsMap.class));
-            } else {
+				if (LOGGER.isWarnEnabled()) {
+					LOGGER.warn(String.format("Cannot map from type " + source.getClass().getName()));
+				}
+				document = Document.create();
+			}
+		}
+		document.setIndex(hit.index());
+		document.setId(hit.id());
 
-                if (LOGGER.isWarnEnabled()) {
-                    LOGGER.warn(String.format("Cannot map from type " + source.getClass().getName()));
-                }
-                document = Document.create();
-            }
-        }
-        document.setIndex(hit.index());
-        document.setId(hit.id());
+		if (hit.version() != null) {
+			document.setVersion(hit.version());
+		}
+		document.setSeqNo(hit.seqNo() != null && hit.seqNo() >= 0 ? hit.seqNo() : -2); // -2 was the default value in the
+		// old client
+		document.setPrimaryTerm(hit.primaryTerm() != null && hit.primaryTerm() > 0 ? hit.primaryTerm() : 0);
 
-        if (hit.version() != null) {
-            document.setVersion(hit.version());
-        }
-        document.setSeqNo(hit.seqNo() != null && hit.seqNo() >= 0 ? hit.seqNo() : -2); // -2 was the default value in the
-        // old client
-        document.setPrimaryTerm(hit.primaryTerm() != null && hit.primaryTerm() > 0 ? hit.primaryTerm() : 0);
+		float score = hit.score() != null ? hit.score().floatValue() : Float.NaN;
+		return new SearchDocumentAdapter(document, score, hit.sort().stream().map(TypeUtils::toObject).toArray(),
+				documentFields, highlightFields, innerHits, nestedMetaData, explanation, matchedQueries, hit.routing());
+	}
 
-        float score = hit.score() != null ? hit.score().floatValue() : Float.NaN;
-        return new SearchDocumentAdapter(document, score, hit.sort().stream().map(TypeUtils::toObject).toArray(),
-                documentFields, highlightFields, innerHits, nestedMetaData, explanation, matchedQueries, hit.routing());
-    }
+	@Nullable
+	private static Object toJavaObject(JsonData jsonData, JsonpMapper jsonpMapper) {
+		return toJavaObject(jsonData.toJson(jsonpMapper));
+	}
 
-    public static SearchDocument from(CompletionSuggestOption<EntityAsMap> completionSuggestOption) {
+	@Nullable
+	private static Object toJavaObject(JsonValue jsonValue) {
 
-        Document document = completionSuggestOption.source() != null ? Document.from(completionSuggestOption.source())
-                : Document.create();
-        document.setIndex(completionSuggestOption.index());
+		return switch (jsonValue.getValueType()) {
+			case OBJECT -> toMap(jsonValue.asJsonObject());
+			case ARRAY -> toList(jsonValue.asJsonArray());
+			case STRING -> ((JsonString) jsonValue).getString();
+			case NUMBER -> toNumber((JsonNumber) jsonValue);
+			case TRUE -> Boolean.TRUE;
+			case FALSE -> Boolean.FALSE;
+			case NULL -> null;
+		};
+	}
 
-        if (completionSuggestOption.id() != null) {
-            document.setId(completionSuggestOption.id());
-        }
+	private static Map<String, @Nullable Object> toMap(JsonObject jsonObject) {
 
-        float score = completionSuggestOption.score() != null ? completionSuggestOption.score().floatValue() : Float.NaN;
-        return new SearchDocumentAdapter(document, score, new Object[]{}, Collections.emptyMap(), Collections.emptyMap(),
-                Collections.emptyMap(), null, null, null, completionSuggestOption.routing());
-    }
+		Map<String, @Nullable Object> result = new LinkedHashMap<>();
+		jsonObject.forEach((key, value) -> result.put(key, toJavaObject(value)));
+		return result;
+	}
 
-    @Nullable
-    private static Explanation from(co.elastic.clients.elasticsearch.core.explain.@Nullable Explanation explanation) {
+	private static List<@Nullable Object> toList(JsonArray jsonArray) {
 
-        if (explanation == null) {
-            return null;
-        }
-        List<Explanation> details = explanation.details().stream().map(DocumentAdapters::from).collect(Collectors.toList());
-        return new Explanation(true, (double) explanation.value(), explanation.description(), details);
-    }
+		List<@Nullable Object> result = new ArrayList<>(jsonArray.size());
+		jsonArray.forEach(value -> result.add(toJavaObject(value)));
+		return result;
+	}
 
-    private static Explanation from(ExplanationDetail explanationDetail) {
+	private static Number toNumber(JsonNumber jsonNumber) {
 
-        List<Explanation> details = explanationDetail.details().stream().map(DocumentAdapters::from)
-                .collect(Collectors.toList());
-        return new Explanation(null, (double) explanationDetail.value(), explanationDetail.description(), details);
-    }
+		if (!jsonNumber.isIntegral()) {
+			return jsonNumber.doubleValue();
+		}
 
-    @Nullable
-    private static NestedMetaData from(@Nullable NestedIdentity nestedIdentity) {
+		try {
+			return jsonNumber.intValueExact();
+		} catch (ArithmeticException ignored) {
+			// continue with a wider numeric type
+		}
 
-        if (nestedIdentity == null) {
-            return null;
-        }
+		try {
+			return jsonNumber.longValueExact();
+		} catch (ArithmeticException ignored) {
+			// continue with a wider numeric type
+		}
 
-        NestedMetaData child = from(nestedIdentity.nested());
-        return NestedMetaData.of(nestedIdentity.field(), nestedIdentity.offset(), child);
-    }
+		BigInteger value = jsonNumber.bigIntegerValue();
+		return value;
+	}
 
-    /**
-     * Creates a {@link Document} from a {@link GetResponse} where the found document is contained as {@link EntityAsMap}.
-     *
-     * @param getResponse the response instance
-     * @return the Document
-     */
-    @Nullable
-    public static Document from(GetResult<EntityAsMap> getResponse) {
+	public static SearchDocument from(CompletionSuggestOption<EntityAsMap> completionSuggestOption) {
 
-        Assert.notNull(getResponse, "getResponse must not be null");
+		Document document = completionSuggestOption.source() != null ? Document.from(completionSuggestOption.source())
+				: Document.create();
+		document.setIndex(completionSuggestOption.index());
 
-        if (!getResponse.found()) {
-            return null;
-        }
+		if (completionSuggestOption.id() != null) {
+			document.setId(completionSuggestOption.id());
+		}
 
-        Document document = getResponse.source() != null ? Document.from(getResponse.source()) : Document.create();
-        document.setIndex(getResponse.index());
-        document.setId(getResponse.id());
+		float score = completionSuggestOption.score() != null ? completionSuggestOption.score().floatValue() : Float.NaN;
+		return new SearchDocumentAdapter(document, score, new Object[] {}, Collections.emptyMap(), Collections.emptyMap(),
+				Collections.emptyMap(), null, null, null, completionSuggestOption.routing());
+	}
 
-        if (getResponse.version() != null) {
-            document.setVersion(getResponse.version());
-        }
+	@Nullable
+	private static Explanation from(co.elastic.clients.elasticsearch.core.explain.@Nullable Explanation explanation) {
 
-        if (getResponse.seqNo() != null) {
-            document.setSeqNo(getResponse.seqNo());
-        }
+		if (explanation == null) {
+			return null;
+		}
+		List<Explanation> details = explanation.details().stream().map(DocumentAdapters::from).collect(Collectors.toList());
+		return new Explanation(true, (double) explanation.value(), explanation.description(), details);
+	}
 
-        if (getResponse.primaryTerm() != null) {
-            document.setPrimaryTerm(getResponse.primaryTerm());
-        }
+	private static Explanation from(ExplanationDetail explanationDetail) {
 
-        return document;
-    }
+		List<Explanation> details = explanationDetail.details().stream().map(DocumentAdapters::from)
+				.collect(Collectors.toList());
+		return new Explanation(null, (double) explanationDetail.value(), explanationDetail.description(), details);
+	}
 
-    /**
-     * Creates a list of {@link MultiGetItem}s from a {@link MgetResponse} where the data is contained as
-     * {@link EntityAsMap} instances.
-     *
-     * @param mgetResponse the response instance
-     * @return list of multiget items
-     */
-    public static List<MultiGetItem<Document>> from(MgetResponse<EntityAsMap> mgetResponse) {
+	@Nullable
+	private static NestedMetaData from(@Nullable NestedIdentity nestedIdentity) {
 
-        Assert.notNull(mgetResponse, "mgetResponse must not be null");
+		if (nestedIdentity == null) {
+			return null;
+		}
 
-        return mgetResponse.docs().stream() //
-                .map(itemResponse -> MultiGetItem.of( //
-                        itemResponse.isFailure() ? null : from(itemResponse.result()), //
-                        ResponseConverter.getFailure(itemResponse)))
-                .collect(Collectors.toList());
-    }
+		NestedMetaData child = from(nestedIdentity.nested());
+		return NestedMetaData.of(nestedIdentity.field(), nestedIdentity.offset(), child);
+	}
+
+	/**
+	 * Creates a {@link Document} from a {@link GetResponse} where the found document is contained as {@link EntityAsMap}.
+	 *
+	 * @param getResponse the response instance
+	 * @return the Document
+	 */
+	@Nullable
+	public static Document from(GetResult<EntityAsMap> getResponse) {
+
+		Assert.notNull(getResponse, "getResponse must not be null");
+
+		if (!getResponse.found()) {
+			return null;
+		}
+
+		Document document = getResponse.source() != null ? Document.from(getResponse.source()) : Document.create();
+		document.setIndex(getResponse.index());
+		document.setId(getResponse.id());
+
+		if (getResponse.version() != null) {
+			document.setVersion(getResponse.version());
+		}
+
+		if (getResponse.seqNo() != null) {
+			document.setSeqNo(getResponse.seqNo());
+		}
+
+		if (getResponse.primaryTerm() != null) {
+			document.setPrimaryTerm(getResponse.primaryTerm());
+		}
+
+		return document;
+	}
+
+	/**
+	 * Creates a list of {@link MultiGetItem}s from a {@link MgetResponse} where the data is contained as
+	 * {@link EntityAsMap} instances.
+	 *
+	 * @param mgetResponse the response instance
+	 * @return list of multiget items
+	 */
+	public static List<MultiGetItem<Document>> from(MgetResponse<EntityAsMap> mgetResponse) {
+
+		Assert.notNull(mgetResponse, "mgetResponse must not be null");
+
+		return mgetResponse.docs().stream() //
+				.map(itemResponse -> MultiGetItem.of( //
+						itemResponse.isFailure() ? null : from(itemResponse.result()), //
+						ResponseConverter.getFailure(itemResponse)))
+				.collect(Collectors.toList());
+	}
 }

src/main/java/org/springframework/data/elasticsearch/client/elc/IndicesTemplate.java

@@ -114,7 +114,7 @@ public class IndicesTemplate extends ChildTemplate<ElasticsearchTransport, Elast
 	}
 
 	@Override
-	public boolean create(Map<String, Object> settings) {
+	public boolean create(Map<String, @Nullable Object> settings) {
 
 		Assert.notNull(settings, "settings must not be null");
 
@@ -122,7 +122,7 @@ public class IndicesTemplate extends ChildTemplate<ElasticsearchTransport, Elast
 	}
 
 	@Override
-	public boolean create(Map<String, Object> settings, Document mapping) {
+	public boolean create(Map<String, @Nullable Object> settings, Document mapping) {
 
 		Assert.notNull(settings, "settings must not be null");
 		Assert.notNull(mapping, "mapping must not be null");
@@ -135,7 +135,7 @@ public class IndicesTemplate extends ChildTemplate<ElasticsearchTransport, Elast
 		return doCreate(getIndexCoordinates(), createSettings(), createMapping());
 	}
 
-	protected boolean doCreate(IndexCoordinates indexCoordinates, Map<String, Object> settings,
+	protected boolean doCreate(IndexCoordinates indexCoordinates, Map<String, @Nullable Object> settings,
 			@Nullable Document mapping) {
 		Set<Alias> aliases = (boundClass != null) ? getAliasesFor(boundClass) : new HashSet<>();
 		CreateIndexSettings indexSettings = CreateIndexSettings.builder(indexCoordinates)
@@ -233,7 +233,7 @@ public class IndicesTemplate extends ChildTemplate<ElasticsearchTransport, Elast
 	}
 
 	@Override
-	public Map<String, Object> getMapping() {
+	public Map<String, @Nullable Object> getMapping() {
 
 		IndexCoordinates indexCoordinates = getIndexCoordinates();
 		GetMappingRequest getMappingRequest = requestConverter.indicesGetMappingRequest(indexCoordinates);

src/main/java/org/springframework/data/elasticsearch/client/elc/ReactiveElasticsearchTemplate.java

@@ -18,9 +18,30 @@ package org.springframework.data.elasticsearch.client.elc;
 import static co.elastic.clients.util.ApiTypeHelper.*;
 import static org.springframework.data.elasticsearch.client.elc.TypeUtils.*;
 
+import co.elastic.clients.elasticsearch._types.Result;
+import co.elastic.clients.elasticsearch.core.*;
+import co.elastic.clients.elasticsearch.core.bulk.BulkResponseItem;
+import co.elastic.clients.elasticsearch.core.search.ResponseBody;
+import co.elastic.clients.json.JsonpMapper;
+import co.elastic.clients.transport.Version;
+import co.elastic.clients.transport.endpoints.BooleanResponse;
+import io.micrometer.observation.Observation;
+import io.micrometer.observation.ObservationRegistry;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
+
+import java.time.Duration;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 import org.reactivestreams.Publisher;
 import org.springframework.beans.BeansException;
@@ -52,28 +73,6 @@ import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
-import java.time.Duration;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-
-import co.elastic.clients.elasticsearch._types.Result;
-import co.elastic.clients.elasticsearch.core.*;
-import co.elastic.clients.elasticsearch.core.bulk.BulkResponseItem;
-import co.elastic.clients.elasticsearch.core.search.ResponseBody;
-import co.elastic.clients.json.JsonpMapper;
-import co.elastic.clients.transport.Version;
-import co.elastic.clients.transport.endpoints.BooleanResponse;
-import io.micrometer.observation.Observation;
-import io.micrometer.observation.ObservationRegistry;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.util.function.Tuple2;
-
 /**
  * Implementation of {@link org.springframework.data.elasticsearch.core.ReactiveElasticsearchOperations} using the new
  * Elasticsearch client.
@@ -269,7 +268,7 @@ public class ReactiveElasticsearchTemplate extends AbstractReactiveElasticsearch
 		ExistsRequest existsRequest = requestConverter.documentExistsRequest(id, routingResolver.getRouting(), index);
 
 		return Mono.from(execute(
-				((ClientCallback<@NonNull Publisher<BooleanResponse>>) client -> client.exists(existsRequest))))
+				((ClientCallback<Publisher<BooleanResponse>>) client -> client.exists(existsRequest))))
 				.map(BooleanResponse::value) //
 				.onErrorReturn(NoSuchIndexException.class, false);
 	}
@@ -381,7 +380,7 @@ public class ReactiveElasticsearchTemplate extends AbstractReactiveElasticsearch
 
 			for (BulkResponseItem item : bulkResponse.items()) {
 
-				if (item.error() != null) {
+				if (item.error() != null && item.id() != null) {
 					failedDocuments.put(item.id(), new BulkFailureException.FailureDetails(item.status(), item.error().reason()));
 				}
 			}
@@ -538,7 +537,7 @@ public class ReactiveElasticsearchTemplate extends AbstractReactiveElasticsearch
 								return Mono.empty();
 							}
 
-							List<Object> sortOptions = hits.get(hits.size() - 1).sort().stream().map(TypeUtils::toObject)
+							List<Object> sortOptions = hits.get(hits.size() - 1).sort().stream().map(TypeUtils::toObjectNotNull)
 									.collect(Collectors.toList());
 							baseQuery.setSearchAfter(sortOptions);
 							SearchRequest followSearchRequest = requestConverter.searchRequest(baseQuery,
@@ -632,8 +631,8 @@ public class ReactiveElasticsearchTemplate extends AbstractReactiveElasticsearch
 		SearchRequest searchRequest = requestConverter.searchRequest(query, routingResolver.getRouting(), clazz, index,
 				false);
 
-		// noinspection unchecked
 		SearchDocumentCallback<T> callback = new ReadSearchDocumentCallback<>((Class<T>) clazz, index);
+
 		SearchDocumentResponse.EntityCreator<T> entityCreator = searchDocument -> callback.toEntity(searchDocument)
 				.toFuture();
 

src/main/java/org/springframework/data/elasticsearch/client/elc/ReactiveIndicesTemplate.java

@@ -108,7 +108,7 @@ public class ReactiveIndicesTemplate
 	}
 
 	@Override
-	public Mono<Boolean> create(Map<String, Object> settings) {
+	public Mono<Boolean> create(Map<String, @Nullable Object> settings) {
 
 		Assert.notNull(settings, "settings must not be null");
 
@@ -116,7 +116,7 @@ public class ReactiveIndicesTemplate
 	}
 
 	@Override
-	public Mono<Boolean> create(Map<String, Object> settings, Document mapping) {
+	public Mono<Boolean> create(Map<String, @Nullable Object> settings, Document mapping) {
 
 		Assert.notNull(settings, "settings must not be null");
 		Assert.notNull(mapping, "mapping must not be null");
@@ -132,7 +132,7 @@ public class ReactiveIndicesTemplate
 				doCreate(getIndexCoordinates(), settings, mapping))); //
 	}
 
-	private Mono<Boolean> doCreate(IndexCoordinates indexCoordinates, Map<String, Object> settings,
+	private Mono<Boolean> doCreate(IndexCoordinates indexCoordinates, Map<String, @Nullable Object> settings,
 			@Nullable Document mapping) {
 		Set<Alias> aliases = (boundClass != null) ? getAliasesFor(boundClass) : new HashSet<>();
 		CreateIndexSettings indexSettings = CreateIndexSettings.builder(indexCoordinates)
@@ -270,7 +270,7 @@ public class ReactiveIndicesTemplate
 		return getAliases(null, indexNames);
 	}
 
-	private Mono<Map<String, Set<AliasData>>> getAliases(@Nullable String[] aliasNames, @Nullable String[] indexNames) {
+	private Mono<Map<String, Set<AliasData>>> getAliases(String@Nullable [] aliasNames, String@Nullable [] indexNames) {
 
 		GetAliasRequest getAliasRequest = requestConverter.indicesGetAliasRequest(aliasNames, indexNames);
 		Mono<GetAliasResponse> getAliasResponse = Mono.from(execute(client -> client.getAlias(getAliasRequest)));

src/main/java/org/springframework/data/elasticsearch/client/elc/RequestConverter.java

@@ -74,6 +74,7 @@ import java.util.Set;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import java.util.Optional;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -113,6 +114,7 @@ import org.springframework.util.StringUtils;
  * @author cdalxndr
  * @author scoobyzhang
  * @author Haibo Liu
+ * @author Steven Pearce
  * @since 4.4
  */
 class RequestConverter extends AbstractQueryProcessor {
@@ -173,17 +175,9 @@ class RequestConverter extends AbstractQueryProcessor {
 	private co.elastic.clients.elasticsearch.indices.Alias.Builder buildAlias(AliasActionParameters parameters,
 			co.elastic.clients.elasticsearch.indices.Alias.Builder aliasBuilder) {
 
-		if (parameters.getRouting() != null) {
-			aliasBuilder.routing(parameters.getRouting());
-		}
-
-		if (parameters.getIndexRouting() != null) {
-			aliasBuilder.indexRouting(parameters.getIndexRouting());
-		}
-
-		if (parameters.getSearchRouting() != null) {
-			aliasBuilder.searchRouting(parameters.getSearchRouting());
-		}
+		getRouting(parameters.getRouting()).ifPresent(aliasBuilder::routing);
+		getRouting(parameters.getIndexRouting()).ifPresent(aliasBuilder::indexRouting);
+		getRouting(parameters.getSearchRouting()).ifPresent(aliasBuilder::searchRouting);
 
 		if (parameters.getHidden() != null) {
 			aliasBuilder.isHidden(parameters.getHidden());
@@ -239,12 +233,16 @@ class RequestConverter extends AbstractQueryProcessor {
 		Map<String, co.elastic.clients.elasticsearch.indices.Alias> aliases = new HashMap<>();
 		for (Alias alias : indexSettings.getAliases()) {
 			co.elastic.clients.elasticsearch.indices.Alias esAlias = co.elastic.clients.elasticsearch.indices.Alias
-					.of(ab -> ab.filter(getQuery(alias.getFilter(), null))
-							.routing(alias.getRouting())
-							.indexRouting(alias.getIndexRouting())
-							.searchRouting(alias.getSearchRouting())
-							.isHidden(alias.getHidden())
-							.isWriteIndex(alias.getWriteIndex()));
+					.of(ab -> {
+						co.elastic.clients.elasticsearch.indices.Alias.Builder aliasBuilder = ab.filter(getQuery(alias.getFilter(), null))
+								.isHidden(alias.getHidden())
+								.isWriteIndex(alias.getWriteIndex());
+						getRouting(alias.getRouting()).ifPresent(aliasBuilder::routing);
+						getRouting(alias.getIndexRouting()).ifPresent(aliasBuilder::indexRouting);
+						getRouting(alias.getSearchRouting()).ifPresent(aliasBuilder::searchRouting);
+
+						return aliasBuilder;
+					});
 			aliases.put(alias.getAlias(), esAlias);
 		}
 
@@ -318,10 +316,11 @@ class RequestConverter extends AbstractQueryProcessor {
 				addActionBuilder //
 						.indices(Arrays.asList(parameters.getIndices())) //
 						.isHidden(parameters.getHidden()) //
-						.isWriteIndex(parameters.getWriteIndex()) //
-						.routing(parameters.getRouting()) //
-						.indexRouting(parameters.getIndexRouting()) //
-						.searchRouting(parameters.getSearchRouting()); //
+						.isWriteIndex(parameters.getWriteIndex()); //
+
+				getRouting(parameters.getRouting()).ifPresent(addActionBuilder::routing);
+				getRouting(parameters.getIndexRouting()).ifPresent(addActionBuilder::indexRouting);
+				getRouting(parameters.getSearchRouting()).ifPresent(addActionBuilder::searchRouting);
 
 				if (parameters.getAliases() != null) {
 					addActionBuilder.aliases(Arrays.asList(parameters.getAliases()));
@@ -589,10 +588,11 @@ class RequestConverter extends AbstractQueryProcessor {
 			builder.version(query.getVersion()).versionType(versionType);
 		}
 
-		builder //
-				.ifSeqNo(query.getSeqNo()) //
-				.ifPrimaryTerm(query.getPrimaryTerm()) //
-				.routing(query.getRouting()); //
+		builder
+				.ifSeqNo(query.getSeqNo())
+				.ifPrimaryTerm(query.getPrimaryTerm());
+
+		getRouting(query.getRouting()).ifPresent(builder::routing);
 
 		if (query.getOpType() != null) {
 			switch (query.getOpType()) {
@@ -642,8 +642,9 @@ class RequestConverter extends AbstractQueryProcessor {
 
 		builder //
 				.ifSeqNo(query.getSeqNo()) //
-				.ifPrimaryTerm(query.getPrimaryTerm()) //
-				.routing(query.getRouting()); //
+				.ifPrimaryTerm(query.getPrimaryTerm()); //
+
+		getRouting(query.getRouting()).ifPresent(builder::routing);
 
 		return builder.build();
 	}
@@ -684,8 +685,9 @@ class RequestConverter extends AbstractQueryProcessor {
 
 		builder //
 				.ifSeqNo(query.getSeqNo()) //
-				.ifPrimaryTerm(query.getPrimaryTerm()) //
-				.routing(query.getRouting()); //
+				.ifPrimaryTerm(query.getPrimaryTerm()); //
+
+		getRouting(query.getRouting()).ifPresent(builder::routing);
 
 		return builder.build();
 	}
@@ -722,11 +724,12 @@ class RequestConverter extends AbstractQueryProcessor {
 		});
 
 		uob
-				.routing(query.getRouting())
 				.ifSeqNo(query.getIfSeqNo())
 				.ifPrimaryTerm(query.getIfPrimaryTerm())
 				.retryOnConflict(query.getRetryOnConflict());
 
+		getRouting(query.getRouting()).ifPresent(uob::routing);
+
 		// no refresh, timeout, waitForActiveShards on UpdateOperation or UpdateAction
 
 		return uob.build();
@@ -776,9 +779,7 @@ class RequestConverter extends AbstractQueryProcessor {
 			builder.pipeline(bulkOptions.getPipeline());
 		}
 
-		if (bulkOptions.getRoutingId() != null) {
-			builder.routing(bulkOptions.getRoutingId());
-		}
+		getRouting(bulkOptions.getRoutingId()).ifPresent(builder::routing);
 
 		List<BulkOperation> operations = queries.stream().map(query -> {
 			BulkOperation.Builder ob = new BulkOperation.Builder();
@@ -805,10 +806,13 @@ class RequestConverter extends AbstractQueryProcessor {
 		Assert.notNull(id, "id must not be null");
 		Assert.notNull(indexCoordinates, "indexCoordinates must not be null");
 
-		return GetRequest.of(grb -> grb //
-				.index(indexCoordinates.getIndexName()) //
-				.id(id) //
-				.routing(routing));
+		return GetRequest.of(grb -> {
+			GetRequest.Builder builder =  grb //
+					.index(indexCoordinates.getIndexName()) //
+					.id(id); //
+			getRouting(routing).ifPresent(builder::routing);
+			return builder;
+		});
 	}
 
 	public co.elastic.clients.elasticsearch.core.ExistsRequest documentExistsRequest(String id, @Nullable String routing,
@@ -817,10 +821,13 @@ class RequestConverter extends AbstractQueryProcessor {
 		Assert.notNull(id, "id must not be null");
 		Assert.notNull(indexCoordinates, "indexCoordinates must not be null");
 
-		return co.elastic.clients.elasticsearch.core.ExistsRequest.of(erb -> erb
-				.index(indexCoordinates.getIndexName())
-				.id(id)
-				.routing(routing));
+		return co.elastic.clients.elasticsearch.core.ExistsRequest.of(erb -> {
+			co.elastic.clients.elasticsearch.core.ExistsRequest.Builder builder = erb
+					.index(indexCoordinates.getIndexName())
+					.id(id);
+			getRouting(routing).ifPresent(builder::routing);
+			return builder;
+		});
 	}
 
 	public <T> MgetRequest documentMgetRequest(Query query, Class<T> clazz, IndexCoordinates index) {
@@ -838,11 +845,14 @@ class RequestConverter extends AbstractQueryProcessor {
 		SourceConfig sourceConfig = getSourceConfig(query);
 
 		List<MultiGetOperation> multiGetOperations = query.getIdsWithRouting().stream()
-				.map(idWithRouting -> MultiGetOperation.of(mgo -> mgo //
-						.index(index.getIndexName()) //
-						.id(idWithRouting.id()) //
-						.routing(idWithRouting.routing()) //
-						.source(sourceConfig)))
+				.map(idWithRouting -> MultiGetOperation.of(mgo -> {
+					MultiGetOperation.Builder builder =  mgo //
+							.index(index.getIndexName()) //
+							.id(idWithRouting.id()) //
+							.source(sourceConfig);
+					getRouting(idWithRouting.routing()).ifPresent(builder::routing);
+					return builder;
+				}))
 				.collect(Collectors.toList());
 
 		return MgetRequest.of(mg -> mg//
@@ -964,10 +974,7 @@ class RequestConverter extends AbstractQueryProcessor {
 
 		return DeleteRequest.of(r -> {
 			r.id(id).index(index.getIndexName());
-
-			if (routing != null) {
-				r.routing(routing);
-			}
+			getRouting(routing).ifPresent(r::routing);
 			r.refresh(refresh(refreshPolicy));
 			return r;
 		});
@@ -991,11 +998,7 @@ class RequestConverter extends AbstractQueryProcessor {
 
 			b.scroll(time(query.getScrollTime()));
 
-			if (query.getRoute() != null) {
-				b.routing(query.getRoute());
-			} else if (StringUtils.hasText(routing)) {
-				b.routing(routing);
-			}
+			getRouting(query.getRoute(), routing).ifPresent(b::routing);
 
 			return b;
 		});
@@ -1015,11 +1018,7 @@ class RequestConverter extends AbstractQueryProcessor {
 					.scroll(time(query.getScroll()))
 					.scrollSize(query.getScrollSize());
 
-			if (query.getRouting() != null) {
-				dqb.routing(query.getRouting());
-			} else if (StringUtils.hasText(routing)) {
-				dqb.routing(routing);
-			}
+			getRouting(query.getRouting(), routing).ifPresent(dqb::routing);
 
 			if (query.getQ() != null) {
 				dqb.q(query.getQ())
@@ -1099,7 +1098,6 @@ class RequestConverter extends AbstractQueryProcessor {
 			uqb
 					.doc(query.getDocument())
 					.upsert(query.getUpsert())
-					.routing(query.getRouting() != null ? query.getRouting() : routing)
 					.scriptedUpsert(query.getScriptedUpsert())
 					.docAsUpsert(query.getDocAsUpsert())
 					.ifSeqNo(query.getIfSeqNo())
@@ -1107,6 +1105,8 @@ class RequestConverter extends AbstractQueryProcessor {
 					.refresh(query.getRefreshPolicy() != null ? refresh(query.getRefreshPolicy()) : refresh(refreshPolicy))
 					.retryOnConflict(query.getRetryOnConflict());
 
+			getRouting(query.getRouting(), routing).ifPresent(uqb::routing);
+
 			if (query.getFetchSource() != null) {
 				uqb.source(sc -> sc.fetch(query.getFetchSource()));
 			}
@@ -1149,13 +1149,14 @@ class RequestConverter extends AbstractQueryProcessor {
 			ub //
 					.index(Arrays.asList(index.getIndexNames())) //
 					.refresh(refreshPolicy == RefreshPolicy.IMMEDIATE) //
-					.routing(updateQuery.getRouting()) //
 					.script(getScript(updateQuery.getScriptData())) //
 					.maxDocs(updateQuery.getMaxDocs() != null ? Long.valueOf(updateQuery.getMaxDocs()) : null) //
 					.pipeline(updateQuery.getPipeline()) //
 					.requestsPerSecond(updateQuery.getRequestsPerSecond()) //
 					.slices(slices(updateQuery.getSlices() != null ? Long.valueOf(updateQuery.getSlices()) : null));
 
+			getRouting(updateQuery.getRouting()).ifPresent(ub::routing);
+
 			if (updateQuery.getAbortOnVersionConflict() != null) {
 				ub.conflicts(updateQuery.getAbortOnVersionConflict() ? Conflicts.Abort : Conflicts.Proceed);
 			}
@@ -1229,12 +1230,7 @@ class RequestConverter extends AbstractQueryProcessor {
 
 		builder.query(getQuery(query, clazz));
 
-		if (StringUtils.hasText(query.getRoute())) {
-			builder.routing(query.getRoute());
-		}
-		if (StringUtils.hasText(routing)) {
-			builder.routing(routing);
-		}
+		getRouting(query.getRoute(), routing).ifPresent(builder::routing);
 
 		addPostFilter(query, builder);
 
@@ -1401,11 +1397,7 @@ class RequestConverter extends AbstractQueryProcessor {
 					.requestCache(query.getRequestCache()) //
 			;
 
-			if (StringUtils.hasText(query.getRoute())) {
-				h.routing(query.getRoute());
-			} else if (StringUtils.hasText(routing)) {
-				h.routing(routing);
-			}
+			getRouting(query.getRoute(), routing).ifPresent(h::routing);
 
 			if (query.getPreference() != null) {
 				h.preference(query.getPreference());
@@ -1451,11 +1443,7 @@ class RequestConverter extends AbstractQueryProcessor {
 				builder.expandWildcards(expandWildcards(expandWildcards));
 			}
 
-			if (query.getRoute() != null) {
-				builder.routing(query.getRoute());
-			} else if (StringUtils.hasText(routing)) {
-				builder.routing(routing);
-			}
+			getRouting(query.getRoute(), routing).ifPresent(builder::routing);
 
 			if (query.getPreference() != null) {
 				builder.preference(query.getPreference());
@@ -1886,11 +1874,7 @@ class RequestConverter extends AbstractQueryProcessor {
 			if (query.getSource() != null) {
 				builder.source(so -> so.scriptString(query.getSource()));
 			}
-			if (query.getRoute() != null) {
-				builder.routing(query.getRoute());
-			} else if (StringUtils.hasText(routing)) {
-				builder.routing(routing);
-			}
+			getRouting(query.getRoute(), routing).ifPresent(builder::routing);
 
 			var expandWildcards = query.getExpandWildcards();
 			if (expandWildcards != null && !expandWildcards.isEmpty()) {
@@ -1990,6 +1974,16 @@ class RequestConverter extends AbstractQueryProcessor {
 		return null;
 	}
 
+	Optional<String> getRouting(@Nullable String routing) {
+		if (StringUtils.hasText(routing)) {
+			return Optional.of(routing);
+		}
+		return Optional.empty();
+	}
+	Optional<String> getRouting(@Nullable String routing1, @Nullable String routing2) {
+		return getRouting(routing1).or(() -> getRouting(routing2));
+	}
+
 	private VersionType retrieveVersionTypeFromPersistentEntity(@Nullable Class<?> clazz) {
 
 		ElasticsearchPersistentEntity<?> persistentEntity = getPersistentEntity(clazz);

src/main/java/org/springframework/data/elasticsearch/client/elc/ResponseConverter.java

@@ -22,7 +22,7 @@ import co.elastic.clients.elasticsearch._types.BulkIndexByScrollFailure;
 import co.elastic.clients.elasticsearch._types.ErrorCause;
 import co.elastic.clients.elasticsearch._types.Time;
 import co.elastic.clients.elasticsearch._types.query_dsl.Query;
-import co.elastic.clients.elasticsearch.cluster.ComponentTemplateSummary;
+import co.elastic.clients.elasticsearch.cluster.ComponentTemplateSummaryRes;
 import co.elastic.clients.elasticsearch.cluster.GetComponentTemplateResponse;
 import co.elastic.clients.elasticsearch.cluster.HealthResponse;
 import co.elastic.clients.elasticsearch.core.DeleteByQueryResponse;
@@ -66,6 +66,7 @@ import org.springframework.data.elasticsearch.core.reindex.ReindexResponse;
 import org.springframework.data.elasticsearch.core.script.Script;
 import org.springframework.data.elasticsearch.core.sql.SqlResponse;
 import org.springframework.data.elasticsearch.support.DefaultStringObjectMap;
+import org.springframework.lang.Contract;
 import org.springframework.util.Assert;
 
 /**
@@ -132,7 +133,7 @@ class ResponseConverter {
 				.build();
 	}
 
-	private TemplateResponseData clusterGetComponentTemplateData(ComponentTemplateSummary componentTemplateSummary) {
+	private TemplateResponseData clusterGetComponentTemplateData(ComponentTemplateSummaryRes componentTemplateSummary) {
 
 		var mapping = typeMapping(componentTemplateSummary.mappings());
 		var settings = new Settings();
@@ -335,11 +336,11 @@ class ResponseConverter {
 				.build();
 	}
 
-	private TemplateResponseData indexGetComponentTemplateData(IndexTemplateSummary indexTemplateSummary,
+	private TemplateResponseData indexGetComponentTemplateData(IndexTemplateSummaryWithRollover indexTemplateSummary,
 			List<String> composedOf) {
 		var mapping = typeMapping(indexTemplateSummary.mappings());
 
-		Function<IndexSettings, Settings> indexSettingsToSettings = indexSettings -> {
+		Function<@Nullable IndexSettings, @Nullable Settings> indexSettingsToSettings = indexSettings -> {
 
 			if (indexSettings == null) {
 				return null;
@@ -497,7 +498,7 @@ class ResponseConverter {
 			builder.withDeleted(response.deleted());
 		}
 
-		if(response.updated() != null) {
+		if (response.updated() != null) {
 			builder.withUpdated(response.updated());
 		}
 
@@ -574,17 +575,20 @@ class ResponseConverter {
 		}
 	}
 
+	@Contract("null -> null; !null -> !null")
 	@Nullable
 	static ElasticsearchErrorCause toErrorCause(@Nullable ErrorCause errorCause) {
 
 		if (errorCause != null) {
-			return new ElasticsearchErrorCause( //
-					errorCause.type(), //
-					errorCause.reason(), //
-					errorCause.stackTrace(), //
-					toErrorCause(errorCause.causedBy()), //
-					errorCause.rootCause().stream().map(ResponseConverter::toErrorCause).collect(Collectors.toList()), //
-					errorCause.suppressed().stream().map(ResponseConverter::toErrorCause).collect(Collectors.toList()));
+			return new ElasticsearchErrorCause(
+					errorCause.type(),
+					errorCause.reason(),
+					errorCause.stackTrace(),
+					toErrorCause(errorCause.causedBy()),
+					(List<ElasticsearchErrorCause>) (errorCause.rootCause().stream()
+							.map(ResponseConverter::toErrorCause).collect(Collectors.toList())),
+					(List<ElasticsearchErrorCause>) (errorCause.suppressed().stream().map(ResponseConverter::toErrorCause)
+							.collect(Collectors.toList())));
 		} else {
 			return null;
 		}

src/main/java/org/springframework/data/elasticsearch/client/elc/TypeUtils.java

@@ -36,6 +36,7 @@ import java.util.EnumSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import org.jspecify.annotations.Nullable;
@@ -144,6 +145,12 @@ final class TypeUtils {
 		}
 	}
 
+	static Object toObjectNotNull(FieldValue fieldValue) {
+
+		Objects.requireNonNull(fieldValue);
+		return toObject(fieldValue);
+	}
+
 	@Nullable
 	static Object toObject(@Nullable FieldValue fieldValue) {
 
@@ -485,7 +492,7 @@ final class TypeUtils {
 	}
 
 	@Nullable
-	static IndexSettings indexSettings(@Nullable Map<String, Object> settings) {
+	static IndexSettings indexSettings(@Nullable Map<String, @Nullable Object> settings) {
 		return settings != null ? IndexSettings.of(b -> b.withJson(new StringReader(Document.from(settings).toJson())))
 				: null;
 	}

src/main/java/org/springframework/data/elasticsearch/client/elc/aot/ElasticsearchClientRuntimeHints.java

@@ -15,15 +15,9 @@
  */
 package org.springframework.data.elasticsearch.client.elc.aot;
 
-import co.elastic.clients.elasticsearch._types.mapping.RuntimeFieldType;
-import co.elastic.clients.elasticsearch._types.mapping.TypeMapping;
-import co.elastic.clients.elasticsearch.indices.IndexSettings;
-import co.elastic.clients.elasticsearch.indices.PutMappingRequest;
-
 import org.jspecify.annotations.Nullable;
 import org.springframework.aot.hint.RuntimeHints;
 import org.springframework.aot.hint.RuntimeHintsRegistrar;
-import org.springframework.aot.hint.TypeReference;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -38,10 +32,14 @@ public class ElasticsearchClientRuntimeHints implements RuntimeHintsRegistrar {
 	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 
 		hints.reflection()
-				.registerType(TypeReference.of(IndexSettings.class), builder -> builder.withField("_DESERIALIZER"))
-				.registerType(TypeReference.of(PutMappingRequest.class), builder -> builder.withField("_DESERIALIZER"))
-				.registerType(TypeReference.of(RuntimeFieldType.class), builder -> builder.withField("_DESERIALIZER"))
-				.registerType(TypeReference.of(TypeMapping.class), builder -> builder.withField("_DESERIALIZER"));
+				.registerTypeIfPresent(classLoader, "co.elastic.clients.elasticsearch.indices.IndexSettings",
+						builder -> builder.withField("_DESERIALIZER"))
+				.registerTypeIfPresent(classLoader, "co.elastic.clients.elasticsearch.indices.PutMappingRequest",
+						builder -> builder.withField("_DESERIALIZER"))
+				.registerTypeIfPresent(classLoader, "co.elastic.clients.elasticsearch._types.mapping.RuntimeFieldType",
+						builder -> builder.withField("_DESERIALIZER"))
+				.registerTypeIfPresent(classLoader, "co.elastic.clients.elasticsearch._types.mapping.TypeMapping",
+						builder -> builder.withField("_DESERIALIZER"));
 
 		if (ClassUtils.isPresent("org.apache.http.impl.auth.BasicScheme",
 				ElasticsearchClientRuntimeHints.class.getClassLoader())) {

src/main/java/org/springframework/data/elasticsearch/client/elc/aot/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.client.elc.aot;

src/main/java/org/springframework/data/elasticsearch/client/elc/rest5_client/Rest5Clients.java

@@ -28,7 +28,6 @@ import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.message.BasicHeader;
 import org.apache.hc.core5.http.nio.ssl.BasicClientTlsStrategy;
 import org.apache.hc.core5.util.Timeout;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 import org.springframework.data.elasticsearch.client.ClientConfiguration;
 import org.springframework.data.elasticsearch.support.HttpHeaders;
@@ -94,16 +93,18 @@ public final class Rest5Clients {
 					throw new RuntimeException(e);
 				}
 			}
-			httpAsyncClientBuilder.addRequestInterceptorFirst((request, entity, context) -> {
-				clientConfiguration.getHeadersSupplier().get().forEach((header, values) -> {
-					// The accept and content-type headers are already put on the request, despite this being the first
-					// interceptor.
-					if ("Accept".equalsIgnoreCase(header) || " Content-Type".equalsIgnoreCase(header)) {
-						request.removeHeaders(header);
-					}
-					values.forEach(value -> request.addHeader(header, value));
-				});
-			});
+			httpAsyncClientBuilder.addExecInterceptorFirst("es-rest5-client",
+					(request, entityProducer, scope, chain, asyncExecCallback) -> {
+						clientConfiguration.getHeadersSupplier().get().forEach((header, values) -> {
+							// The accept and content-type headers may already be put on the request, despite this being the
+							// first interceptor.
+							if ("Accept".equalsIgnoreCase(header) || "Content-Type".equalsIgnoreCase(header)) {
+								request.removeHeaders(header);
+							}
+							values.forEach(value -> request.addHeader(header, value));
+						});
+						chain.proceed(request, entityProducer, scope, asyncExecCallback);
+					});
 
 			// add httpclient configurator callbacks provided by the configuration
 			for (ClientConfiguration.ClientConfigurationCallback<?> clientConfigurer : clientConfiguration
@@ -181,7 +182,7 @@ public final class Rest5Clients {
 		return builder;
 	}
 
-	private static HttpHost @NonNull [] getHttpHosts(ClientConfiguration clientConfiguration) {
+	private static HttpHost[] getHttpHosts(ClientConfiguration clientConfiguration) {
 		List<InetSocketAddress> hosts = clientConfiguration.getEndpoints();
 		boolean useSsl = clientConfiguration.useSsl();
 		return hosts.stream()

src/main/java/org/springframework/data/elasticsearch/client/elc/rest_client/RestClients.java

@@ -21,10 +21,8 @@ import org.apache.http.protocol.HttpContext;
 import org.elasticsearch.client.RequestOptions;
 import org.elasticsearch.client.RestClient;
 import org.elasticsearch.client.RestClientBuilder;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 import org.springframework.data.elasticsearch.client.ClientConfiguration;
-import org.springframework.data.elasticsearch.client.elc.ElasticsearchClients;
 import org.springframework.data.elasticsearch.support.HttpHeaders;
 import org.springframework.util.Assert;
 
@@ -107,7 +105,7 @@ public final class RestClients {
 		return builder;
 	}
 
-	private static HttpHost @NonNull [] getHttpHosts(ClientConfiguration clientConfiguration) {
+	private static HttpHost[] getHttpHosts(ClientConfiguration clientConfiguration) {
 		List<InetSocketAddress> hosts = clientConfiguration.getEndpoints();
 		boolean useSsl = clientConfiguration.useSsl();
 		return hosts.stream()
@@ -130,10 +128,10 @@ public final class RestClients {
 	record CustomHeaderInjector(Supplier<HttpHeaders> headersSupplier) implements HttpRequestInterceptor {
 
 		@Override
-		public void process(HttpRequest request, HttpContext context) {
+		public void process(@Nullable HttpRequest request, @Nullable HttpContext context) {
 			HttpHeaders httpHeaders = headersSupplier.get();
 
-			if (httpHeaders != null && !httpHeaders.isEmpty()) {
+			if (!httpHeaders.isEmpty() && request != null) {
 				Arrays.stream(toHeaderArray(httpHeaders)).forEach(request::addHeader);
 			}
 		}

src/main/java/org/springframework/data/elasticsearch/client/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.client;

src/main/java/org/springframework/data/elasticsearch/client/util/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.client.util;

src/main/java/org/springframework/data/elasticsearch/config/ElasticsearchConfigurationSupport.java

@@ -18,6 +18,7 @@ package org.springframework.data.elasticsearch.config;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import org.jspecify.annotations.Nullable;
@@ -41,6 +42,7 @@ import org.springframework.util.StringUtils;
 /**
  * @author Christoph Strobl
  * @author Peter-Josef Meisch
+ * @author Steven Pearce
  * @since 3.2
  */
 @Configuration(proxyBeanMethods = false)
@@ -72,6 +74,7 @@ public class ElasticsearchConfigurationSupport {
 		mappingContext.setSimpleTypeHolder(elasticsearchCustomConversions.getSimpleTypeHolder());
 		mappingContext.setFieldNamingStrategy(fieldNamingStrategy());
 		mappingContext.setWriteTypeHints(writeTypeHints());
+		mappingContext.setServerType(serverType());
 
 		return mappingContext;
 	}
@@ -98,7 +101,7 @@ public class ElasticsearchConfigurationSupport {
 	protected Collection<String> getMappingBasePackages() {
 
 		Package mappingBasePackage = getClass().getPackage();
-		return Collections.singleton(mappingBasePackage == null ? null : mappingBasePackage.getName());
+		return mappingBasePackage == null ? Collections.emptyList() : List.of(mappingBasePackage.getName());
 	}
 
 	/**
@@ -173,7 +176,7 @@ public class ElasticsearchConfigurationSupport {
 	}
 
 	/**
-	 * Flag specifiying if type hints (_class fields) should be written in the index. It is strongly advised to keep the
+	 * Flag specifying if type hints (_class fields) should be written in the index. It is strongly advised to keep the
 	 * default value of {@literal true}. If you need to write to an existing index that does not have a mapping defined
 	 * for these fields and that has a strict mapping set, then it might be necessary to disable type hints. But notice
 	 * that in this case reading polymorphic types may fail.
@@ -184,4 +187,15 @@ public class ElasticsearchConfigurationSupport {
 	protected boolean writeTypeHints() {
 		return true;
 	}
+
+	/**
+	 * Configures the {@link ElasticsearchServerType} to use when creating indexes. The Default value will support the
+	 * standard configurations, and SERVERLESS will support ElasticSearch Serverless
+	 *
+	 * @return the {@link ElasticsearchServerType} to use
+	 * @since 6.2
+	 */
+	protected ElasticsearchServerType serverType() {
+		return ElasticsearchServerType.DEFAULT;
+	}
 }

src/main/java/org/springframework/data/elasticsearch/config/ElasticsearchServerType.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2026-present 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.elasticsearch.config;
+
+
+/**
+ * ElasticsearchServerType defines the type of Elasticsearch server you are connecting to.
+ *  @see #DEFAULT
+ *  @see #SERVERLESS
+ *
+ * @author Steven Pearce
+ * @since 6.2
+ */
+public enum ElasticsearchServerType {
+  /**
+   * Normal installations of Elasticsearch including cloud-hosted Elasticsearch
+   */
+  DEFAULT,
+  /**
+   * New Flavour of Elasticsearch, offered by Elastic
+   */
+  SERVERLESS,
+}

src/main/java/org/springframework/data/elasticsearch/config/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.config;

src/main/java/org/springframework/data/elasticsearch/core/AbstractElasticsearchTemplate.java

@@ -59,6 +59,7 @@ import org.springframework.data.elasticsearch.support.VersionInfo;
 import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.util.Streamable;
+import org.springframework.lang.Contract;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -260,7 +261,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 		List<IndexedObjectInformation> indexedObjectInformationList = bulkIndex(indexQueries, index);
 		Iterator<IndexedObjectInformation> iterator = indexedObjectInformationList.iterator();
 
-		// noinspection unchecked
+		// noinspection unchecked,DataFlowIssue
 		return indexQueries.stream() //
 				.map(IndexQuery::getObject) //
 				.map(entity -> (T) entityOperations.updateIndexedObject(
@@ -593,7 +594,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 	}
 
 	protected <T> SearchDocumentResponse.EntityCreator<T> getEntityCreator(ReadDocumentCallback<T> documentCallback) {
-		return searchDocument -> CompletableFuture.completedFuture(documentCallback.doWith(searchDocument));
+		return searchDocument -> CompletableFuture.<T> completedFuture(documentCallback.doWith(searchDocument));
 	}
 
 	/**
@@ -752,6 +753,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 
 	// region Document callbacks
 	protected interface DocumentCallback<T> {
+		@Contract("null -> null")
 		@Nullable
 		T doWith(@Nullable Document document);
 	}
@@ -815,6 +817,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 
 		@Override
 		public SearchHits<T> doWith(SearchDocumentResponse response) {
+			// noinspection NullableProblems,DataFlowIssue
 			List<T> entities = response.getSearchDocuments().stream().map(delegate::doWith).collect(Collectors.toList());
 			return SearchHitMapping.mappingFor(type, elasticsearchConverter).mapHits(response, entities);
 		}
@@ -835,6 +838,7 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 
 		@Override
 		public SearchScrollHits<T> doWith(SearchDocumentResponse response) {
+			// noinspection DataFlowIssue,NullableProblems
 			List<T> entities = response.getSearchDocuments().stream().map(delegate::doWith).collect(Collectors.toList());
 			return SearchHitMapping.mappingFor(type, elasticsearchConverter).mapScrollHits(response, entities);
 		}

src/main/java/org/springframework/data/elasticsearch/core/AbstractReactiveElasticsearchTemplate.java

@@ -766,7 +766,8 @@ abstract public class AbstractReactiveElasticsearchTemplate
 	/**
 	 * Value class to capture client independent information from a response to an index request.
 	 */
-	public record IndexResponseMetaData(String id, String index, long seqNo, long primaryTerm, long version) {
+	public record IndexResponseMetaData(String id, String index, @Nullable Long seqNo, @Nullable Long primaryTerm,
+			long version) {
 	}
 	// endregion
 

src/main/java/org/springframework/data/elasticsearch/core/EntityOperations.java

@@ -17,7 +17,6 @@ package org.springframework.data.elasticsearch.core;
 
 import java.util.Map;
 
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
@@ -370,7 +369,7 @@ public class EntityOperations {
 		 * @see org.springframework.data.elasticsearch.core.EntityOperations.AdaptableEntity#initializeVersionProperty()
 		 */
 		@Override
-		public @NonNull T initializeVersionProperty() {
+		public T initializeVersionProperty() {
 			return map;
 		}
 
@@ -399,7 +398,7 @@ public class EntityOperations {
 		 * @see org.springframework.data.elasticsearch.core.EntityOperations.AdaptableEntity#incrementVersion()
 		 */
 		@Override
-		public @NonNull T incrementVersion() {
+		public T incrementVersion() {
 			return map;
 		}
 
@@ -408,7 +407,7 @@ public class EntityOperations {
 		 * @see org.springframework.data.elasticsearch.core.EntityOperations.Entity#getBean()
 		 */
 		@Override
-		public @NonNull T getBean() {
+		public T getBean() {
 			return map;
 		}
 

src/main/java/org/springframework/data/elasticsearch/core/IndexOperations.java

@@ -52,7 +52,7 @@ public interface IndexOperations {
 	 * @param settings the index settings
 	 * @return {@literal true} if the index was created
 	 */
-	boolean create(Map<String, Object> settings);
+	boolean create(Map<String, @Nullable Object> settings);
 
 	/**
 	 * Create an index for given settings and mapping.
@@ -62,7 +62,7 @@ public interface IndexOperations {
 	 * @return {@literal true} if the index was created
 	 * @since 4.2
 	 */
-	boolean create(Map<String, Object> settings, Document mapping);
+	boolean create(Map<String, @Nullable Object> settings, Document mapping);
 
 	/**
 	 * Create an index with the settings and mapping defined for the entity this IndexOperations is bound to.
@@ -142,7 +142,7 @@ public interface IndexOperations {
 	 *
 	 * @return the mapping
 	 */
-	Map<String, Object> getMapping();
+	Map<String, @Nullable Object> getMapping();
 
 	// endregion
 

src/main/java/org/springframework/data/elasticsearch/core/IndexOperationsAdapter.java

@@ -46,12 +46,12 @@ public interface IndexOperationsAdapter extends IndexOperations {
 			}
 
 			@Override
-			public boolean create(Map<String, Object> settings) {
+			public boolean create(Map<String, @Nullable Object> settings) {
 				return Boolean.TRUE.equals(reactiveIndexOperations.create(settings).block());
 			}
 
 			@Override
-			public boolean create(Map<String, Object> settings, Document mapping) {
+			public boolean create(Map<String, @Nullable Object> settings, Document mapping) {
 				return Boolean.TRUE.equals(reactiveIndexOperations.create(settings, mapping).block());
 			}
 
@@ -92,7 +92,7 @@ public interface IndexOperationsAdapter extends IndexOperations {
 			}
 
 			@Override
-			public Map<String, Object> getMapping() {
+			public Map<String, @Nullable Object> getMapping() {
 				return Objects.requireNonNull(reactiveIndexOperations.getMapping().block());
 			}
 

src/main/java/org/springframework/data/elasticsearch/core/MultiGetItem.java

@@ -36,7 +36,7 @@ public class MultiGetItem<T> {
 	}
 
 	public static <T> MultiGetItem<T> of(@Nullable T item, @Nullable Failure failure) {
-		return new MultiGetItem<>(item, failure);
+		return new MultiGetItem(item, failure);
 	}
 
 	public boolean hasItem() {

src/main/java/org/springframework/data/elasticsearch/core/ReactiveIndexOperations.java

@@ -21,6 +21,7 @@ import reactor.core.publisher.Mono;
 import java.util.Map;
 import java.util.Set;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.elasticsearch.core.document.Document;
 import org.springframework.data.elasticsearch.core.index.*;
 import org.springframework.data.elasticsearch.core.mapping.IndexCoordinates;
@@ -50,7 +51,7 @@ public interface ReactiveIndexOperations {
 	 * @return a {@link Mono} signalling successful operation completion or an {@link Mono#error(Throwable) error} if eg.
 	 *         the index already exist.
 	 */
-	Mono<Boolean> create(Map<String, Object> settings);
+	Mono<Boolean> create(Map<String, @Nullable Object> settings);
 
 	/**
 	 * Create an index for given settings and mapping.
@@ -61,7 +62,7 @@ public interface ReactiveIndexOperations {
 	 *         the index already exist.
 	 * @since 4.2
 	 */
-	Mono<Boolean> create(Map<String, Object> settings, Document mapping);
+	Mono<Boolean> create(Map<String, @Nullable Object> settings, Document mapping);
 
 	/**
 	 * Create an index with the settings and mapping defined for the entity this IndexOperations is bound to.

src/main/java/org/springframework/data/elasticsearch/core/SearchHit.java

@@ -51,7 +51,7 @@ public class SearchHit<T> {
 	private final Map<String, Double> matchedQueries = new LinkedHashMap<>();
 
 	public SearchHit(@Nullable String index, @Nullable String id, @Nullable String routing, float score,
-			@Nullable Object[] sortValues, @Nullable Map<String, List<String>> highlightFields,
+			Object @Nullable [] sortValues, @Nullable Map<String, List<String>> highlightFields,
 			@Nullable Map<String, SearchHits<?>> innerHits, @Nullable NestedMetaData nestedMetaData,
 			@Nullable Explanation explanation, @Nullable Map<String, Double> matchedQueries, T content) {
 		this.index = index;
@@ -193,7 +193,6 @@ public class SearchHit<T> {
 	/**
 	 * @return the matched queries for this SearchHit.
 	 */
-	@Nullable
 	public Map<String, Double> getMatchedQueries() {
 		return matchedQueries;
 	}

src/main/java/org/springframework/data/elasticsearch/core/SearchHitSupport.java

@@ -22,11 +22,11 @@ import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import org.jspecify.annotations.Nullable;
-
 import org.springframework.data.core.ReactiveWrappers;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.util.CloseableIterator;
+import org.springframework.lang.Contract;
 
 /**
  * Utility class with helper methods for working with {@link SearchHit}.
@@ -47,6 +47,7 @@ public final class SearchHitSupport {
 	 * @return a corresponding object where the SearchHits are replaced by their content if possible, otherwise the
 	 *         original object
 	 */
+	@Contract("null -> null; !null -> !null")
 	@Nullable
 	public static Object unwrapSearchHits(@Nullable Object result) {
 

src/main/java/org/springframework/data/elasticsearch/core/SearchHitsImpl.java

@@ -133,7 +133,7 @@ public class SearchHitsImpl<T> implements SearchScrollHits<T> {
 	}
 
 	@Override
-	public SearchShardStatistics getSearchShardStatistics() {
+	public @Nullable SearchShardStatistics getSearchShardStatistics() {
 		return searchShardStatistics;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/cluster/package-info.java

@@ -1,5 +1,18 @@
-/**
- * Interfaces and classes related to Elasticsearch cluster information and management.
+/*
+ * Copyright 2022-present 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.
  */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.cluster;

src/main/java/org/springframework/data/elasticsearch/core/convert/ElasticsearchTypeMapper.java

@@ -29,7 +29,7 @@ import org.springframework.data.mapping.context.MappingContext;
  * @author Christoph Strobl
  * @since 3.2
  */
-public interface ElasticsearchTypeMapper extends TypeMapper<Map<String, Object>> {
+public interface ElasticsearchTypeMapper extends TypeMapper<Map<String, @Nullable Object>> {
 
 	String DEFAULT_TYPE_KEY = "_class";
 
@@ -47,7 +47,7 @@ public interface ElasticsearchTypeMapper extends TypeMapper<Map<String, Object>>
 	@Nullable
 	String getTypeKey();
 
-	default boolean containsTypeInformation(Map<String, Object> source) {
+	default boolean containsTypeInformation(Map<String, @Nullable Object> source) {
 		return readType(source) != null;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/convert/GeoConverters.java

@@ -20,9 +20,9 @@ import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.convert.ReadingConverter;
 import org.springframework.data.convert.WritingConverter;
@@ -167,7 +167,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJson<? extends Iterable<?>> convert(Map<String, Object> source) {
+		public GeoJson<? extends Iterable<?>> convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 
@@ -206,7 +206,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonPoint convert(Map<String, Object> source) {
+		public GeoJsonPoint convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonPoint.TYPE), "does not contain a type 'Point'");
@@ -244,7 +244,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonMultiPoint convert(Map<String, Object> source) {
+		public GeoJsonMultiPoint convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonMultiPoint.TYPE), "does not contain a type 'MultiPoint'");
@@ -279,7 +279,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonLineString convert(Map<String, Object> source) {
+		public GeoJsonLineString convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonLineString.TYPE), "does not contain a type 'LineString'");
@@ -311,7 +311,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonMultiLineString convert(Map<String, Object> source) {
+		public GeoJsonMultiLineString convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonMultiLineString.TYPE), "does not contain a type 'MultiLineString'");
@@ -339,7 +339,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonPolygon convert(Map<String, Object> source) {
+		public GeoJsonPolygon convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonPolygon.TYPE), "does not contain a type 'Polygon'");
@@ -368,7 +368,6 @@ public class GeoConverters {
 
 			List<Object> coordinates = source.getCoordinates().stream() //
 					.map(GeoJsonPolygonToMapConverter.INSTANCE::convert) //
-					.filter(Objects::nonNull) //
 					.map(it -> it.get("coordinates")) //
 					.collect(Collectors.toList()); //
 			map.put("coordinates", coordinates);
@@ -383,7 +382,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonMultiPolygon convert(Map<String, Object> source) {
+		public GeoJsonMultiPolygon convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonMultiPolygon.TYPE), "does not contain a type 'MultiPolygon'");
@@ -430,7 +429,7 @@ public class GeoConverters {
 		INSTANCE;
 
 		@Override
-		public GeoJsonGeometryCollection convert(Map<String, Object> source) {
+		public GeoJsonGeometryCollection convert(Map<String, @Nullable Object> source) {
 
 			String type = GeoConverters.getGeoJsonType(source);
 			Assert.isTrue(type.equalsIgnoreCase(GeoJsonGeometryCollection.TYPE),
@@ -448,7 +447,7 @@ public class GeoConverters {
 	// endregion
 
 	// region helper functions
-	private static String getGeoJsonType(Map<String, Object> source) {
+	private static String getGeoJsonType(Map<String, @Nullable Object> source) {
 
 		Object type = source.get("type");
 		Assert.notNull(type, "Document to convert does not contain a type");
@@ -485,7 +484,7 @@ public class GeoConverters {
 		return map;
 	}
 
-	private static List<GeoJsonLineString> geoJsonLineStringsFromMap(Map<String, Object> source) {
+	private static List<GeoJsonLineString> geoJsonLineStringsFromMap(Map<String, @Nullable Object> source) {
 		Object coordinates = source.get("coordinates");
 		Assert.notNull(coordinates, "Document to convert does not contain coordinates");
 		Assert.isTrue(coordinates instanceof List, "coordinates must be a List");

src/main/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverter.java

@@ -24,7 +24,6 @@ import java.util.stream.Collectors;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.jspecify.annotations.Nullable;
-
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ApplicationContext;
@@ -63,16 +62,7 @@ import org.springframework.data.mapping.Parameter;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.SimplePropertyHandler;
 import org.springframework.data.mapping.context.MappingContext;
-import org.springframework.data.mapping.model.CachingValueExpressionEvaluatorFactory;
-import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
-import org.springframework.data.mapping.model.EntityInstantiator;
-import org.springframework.data.mapping.model.EntityInstantiators;
-import org.springframework.data.mapping.model.ParameterValueProvider;
-import org.springframework.data.mapping.model.PersistentEntityParameterValueProvider;
-import org.springframework.data.mapping.model.PropertyValueProvider;
-import org.springframework.data.mapping.model.SpELContext;
-import org.springframework.data.mapping.model.ValueExpressionEvaluator;
-import org.springframework.data.mapping.model.ValueExpressionParameterValueProvider;
+import org.springframework.data.mapping.model.*;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.format.datetime.DateFormatterRegistrar;
 import org.springframework.util.Assert;
@@ -114,9 +104,8 @@ public class MappingElasticsearchConverter
 	protected @Nullable Environment environment;
 
 	private final SpELContext spELContext = new SpELContext(new MapAccessor());
-	private final SpelExpressionParser expressionParser = new SpelExpressionParser();
 	private final CachingValueExpressionEvaluatorFactory expressionEvaluatorFactory = new CachingValueExpressionEvaluatorFactory(
-			expressionParser, this, spELContext);
+			new SpelExpressionParser(), this, spELContext);
 
 	private final EntityInstantiators instantiators = new EntityInstantiators();
 	private final ElasticsearchTypeMapper typeMapper;
@@ -267,7 +256,7 @@ public class MappingElasticsearchConverter
 
 		@Nullable
 		@SuppressWarnings("unchecked")
-		private <R> R read(TypeInformation<R> typeInformation, Map<String, Object> source) {
+		private <R> R read(TypeInformation<R> typeInformation, Map<String, @Nullable Object> source) {
 
 			Assert.notNull(source, "Source must not be null!");
 
@@ -301,7 +290,7 @@ public class MappingElasticsearchConverter
 		}
 
 		@SuppressWarnings("unchecked")
-		private <R> R readMap(TypeInformation<?> type, Map<String, Object> source) {
+		private <R> R readMap(TypeInformation<?> type, Map<String, @Nullable Object> source) {
 
 			Assert.notNull(source, "Document must not be null!");
 
@@ -313,9 +302,10 @@ public class MappingElasticsearchConverter
 			Class<?> rawKeyType = keyType != null ? keyType.getType() : null;
 			Class<?> rawValueType = valueType != null ? valueType.getType() : null;
 
-			Map<Object, Object> map = CollectionFactory.createMap(mapType, rawKeyType, source.keySet().size());
+			Map<Object, @Nullable Object> map = (Map<Object, @Nullable Object>) CollectionFactory.createMap(mapType,
+					rawKeyType, source.keySet().size());
 
-			for (Entry<String, Object> entry : source.entrySet()) {
+			for (Entry<String, @Nullable Object> entry : source.entrySet()) {
 
 				if (typeMapper.isTypeKey(entry.getKey())) {
 					continue;
@@ -325,6 +315,7 @@ public class MappingElasticsearchConverter
 
 				if (rawKeyType != null && !rawKeyType.isAssignableFrom(key.getClass())) {
 					key = conversionService.convert(key, rawKeyType);
+					Assert.notNull(key, "converted key must not be null");
 				}
 
 				Object value = entry.getValue();
@@ -343,7 +334,7 @@ public class MappingElasticsearchConverter
 			return (R) map;
 		}
 
-		private <R> R readEntity(ElasticsearchPersistentEntity<?> entity, Map<String, Object> source) {
+		private <R> R readEntity(ElasticsearchPersistentEntity<?> entity, Map<String, @Nullable Object> source) {
 
 			ElasticsearchPersistentEntity<?> targetEntity = computeClosestEntity(entity, source);
 			ValueExpressionEvaluator evaluator = expressionEvaluatorFactory.create(source);
@@ -582,7 +573,7 @@ public class MappingElasticsearchConverter
 					: TypeInformation.OBJECT;
 			Class<?> rawComponentType = componentType.getType();
 
-			Collection<Object> items = targetType.getType().isArray() //
+			Collection<@Nullable Object> items = targetType.getType().isArray() //
 					? new ArrayList<>(source.size()) //
 					: CollectionFactory.createCollection(collectionType, rawComponentType, source.size());
 
@@ -672,7 +663,7 @@ public class MappingElasticsearchConverter
 		 */
 		private <T> void populateScriptedFields(ElasticsearchPersistentEntity<?> entity, T result,
 				SearchDocument searchDocument) {
-			Map<String, List<Object>> fields = searchDocument.getFields();
+			Map<String, List<@Nullable Object>> fields = searchDocument.getFields();
 			entity.doWithProperties((SimplePropertyHandler) property -> {
 				if (property.isAnnotationPresent(ScriptedField.class)) {
 					ScriptedField scriptedField = property.findAnnotation(ScriptedField.class);
@@ -695,7 +686,7 @@ public class MappingElasticsearchConverter
 		 * Compute the type to use by checking the given entity against the store type;
 		 */
 		private ElasticsearchPersistentEntity<?> computeClosestEntity(ElasticsearchPersistentEntity<?> entity,
-				Map<String, Object> source) {
+				Map<String, @Nullable Object> source) {
 
 			TypeInformation<?> typeToUse = typeMapper.readType(source);
 
@@ -770,7 +761,7 @@ public class MappingElasticsearchConverter
 			INSTANCE;
 
 			@Override
-			public <T> T getParameterValue(Parameter<T, ElasticsearchPersistentProperty> parameter) {
+			public <T> @Nullable T getParameterValue(Parameter<T, ElasticsearchPersistentProperty> parameter) {
 				return null;
 			}
 		}
@@ -822,7 +813,7 @@ public class MappingElasticsearchConverter
 		 * @param typeInformation type information for the source
 		 */
 		@SuppressWarnings("unchecked")
-		private void writeInternal(@Nullable Object source, Map<String, Object> sink,
+		private void writeInternal(@Nullable Object source, Map<String, @Nullable Object> sink,
 				@Nullable TypeInformation<?> typeInformation) {
 
 			if (null == source) {
@@ -833,7 +824,7 @@ public class MappingElasticsearchConverter
 			Optional<Class<?>> customTarget = conversions.getCustomWriteTarget(entityType, Map.class);
 
 			if (customTarget.isPresent()) {
-				Map<String, Object> result = conversionService.convert(source, Map.class);
+				Map<String, @Nullable Object> result = conversionService.convert(source, Map.class);
 
 				if (result != null) {
 					sink.putAll(result);
@@ -863,7 +854,7 @@ public class MappingElasticsearchConverter
 		 * @param sink the destination
 		 * @param entity entity for the source
 		 */
-		private void writeInternal(@Nullable Object source, Map<String, Object> sink,
+		private void writeInternal(@Nullable Object source, Map<String, @Nullable Object> sink,
 				@Nullable ElasticsearchPersistentEntity<?> entity) {
 
 			if (source == null) {
@@ -905,7 +896,7 @@ public class MappingElasticsearchConverter
 		 * @param sink must not be {@literal null}.
 		 * @param propertyType must not be {@literal null}.
 		 */
-		private Map<String, Object> writeMapInternal(Map<?, ?> source, Map<String, Object> sink,
+		private Map<String, @Nullable Object> writeMapInternal(Map<?, ?> source, Map<String, @Nullable Object> sink,
 				TypeInformation<?> propertyType) {
 
 			for (Map.Entry<?, ?> entry : source.entrySet()) {
@@ -922,7 +913,7 @@ public class MappingElasticsearchConverter
 						sink.put(simpleKey,
 								writeCollectionInternal(asCollection(value), propertyType.getMapValueType(), new ArrayList<>()));
 					} else {
-						Map<String, Object> document = Document.create();
+						Map<String, @Nullable Object> document = Document.create();
 						TypeInformation<?> valueTypeInfo = propertyType.isMap() ? propertyType.getMapValueType()
 								: TypeInformation.OBJECT;
 						writeInternal(value, document, valueTypeInfo);
@@ -966,7 +957,7 @@ public class MappingElasticsearchConverter
 				} else if (element instanceof Collection || elementType.isArray()) {
 					collection.add(writeCollectionInternal(asCollection(element), componentType, new ArrayList<>()));
 				} else {
-					Map<String, Object> document = Document.create();
+					Map<String, @Nullable Object> document = Document.create();
 					writeInternal(element, document, componentType);
 					collection.add(document);
 				}
@@ -1080,7 +1071,7 @@ public class MappingElasticsearchConverter
 					: mappingContext.getRequiredPersistentEntity(type);
 
 			Object existingValue = sink.get(property);
-			Map<String, Object> document = existingValue instanceof Map ? (Map<String, Object>) existingValue
+			Map<String, @Nullable Object> document = existingValue instanceof Map ? (Map<String, Object>) existingValue
 					: Document.create();
 
 			addCustomTypeKeyIfNecessary(value, document, TypeInformation.of(property.getRawType()));
@@ -1097,7 +1088,7 @@ public class MappingElasticsearchConverter
 		 * @param sink must not be {@literal null}.
 		 * @param type type to compare to
 		 */
-		private void addCustomTypeKeyIfNecessary(Object source, Map<String, Object> sink,
+		private void addCustomTypeKeyIfNecessary(Object source, Map<String, @Nullable Object> sink,
 				@Nullable TypeInformation<?> type) {
 
 			if (!writeTypeHints) {
@@ -1218,7 +1209,7 @@ public class MappingElasticsearchConverter
 			Assert.notNull(map, "Given map must not be null!");
 			Assert.notNull(property, "PersistentProperty must not be null!");
 
-			return writeMapInternal(map, new LinkedHashMap<>(map.size()), property.getTypeInformation());
+			return writeMapInternal(map, new LinkedHashMap(map.size()), property.getTypeInformation());
 		}
 
 		/**
@@ -1492,9 +1483,9 @@ public class MappingElasticsearchConverter
 	@SuppressWarnings("ClassCanBeRecord")
 	static class MapValueAccessor {
 
-		final Map<String, Object> target;
+		final Map<String, @Nullable Object> target;
 
-		MapValueAccessor(Map<String, Object> target) {
+		MapValueAccessor(Map<String, @Nullable Object> target) {
 			this.target = target;
 		}
 
@@ -1528,7 +1519,7 @@ public class MappingElasticsearchConverter
 			}
 
 			Iterator<String> parts = Arrays.asList(fieldName.split("\\.")).iterator();
-			Map<String, Object> source = target;
+			Map<String, @Nullable Object> source = target;
 			Object result = null;
 
 			while (parts.hasNext()) {
@@ -1559,11 +1550,11 @@ public class MappingElasticsearchConverter
 			target.put(property.getFieldName(), value);
 		}
 
-		private Map<String, Object> getAsMap(Object result) {
+		private Map<String, @Nullable Object> getAsMap(Object result) {
 
 			if (result instanceof Map) {
 				// noinspection unchecked
-				return (Map<String, Object>) result;
+				return (Map<String, @Nullable Object>) result;
 			}
 
 			throw new IllegalArgumentException(String.format("%s is not a Map.", result));

src/main/java/org/springframework/data/elasticsearch/core/convert/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.convert;

src/main/java/org/springframework/data/elasticsearch/core/document/Explanation.java

@@ -62,7 +62,7 @@ public class Explanation {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())
@@ -81,7 +81,7 @@ public class Explanation {
 
 	@Override
 	public int hashCode() {
-		int result = (match ? 1 : 0);
+		int result = (Boolean.TRUE.equals(match) ? 1 : 0);
 		result = 31 * result + value.hashCode();
 		result = 31 * result + (description != null ? description.hashCode() : 0);
 		result = 31 * result + details.hashCode();

src/main/java/org/springframework/data/elasticsearch/core/document/MapDocument.java

@@ -215,7 +215,7 @@ class MapDocument implements Document {
 	 * @see java.util.Map#containsKey(java.lang.Object)
 	 */
 	@Override
-	public boolean containsKey(Object key) {
+	public boolean containsKey(@Nullable Object key) {
 		return documentAsMap.containsKey(key);
 	}
 
@@ -224,7 +224,7 @@ class MapDocument implements Document {
 	 * @see java.util.Map#containsValue(java.lang.Object)
 	 */
 	@Override
-	public boolean containsValue(Object value) {
+	public boolean containsValue(@Nullable Object value) {
 		return documentAsMap.containsValue(value);
 	}
 
@@ -233,7 +233,7 @@ class MapDocument implements Document {
 	 * @see java.util.Map#get(java.lang.Object)
 	 */
 	@Override
-	public Object get(Object key) {
+	public Object get(@Nullable Object key) {
 		return documentAsMap.get(key);
 	}
 
@@ -242,7 +242,7 @@ class MapDocument implements Document {
 	 * @see java.lang.Object#getOrDefault(java.lang.Object, java.lang.Object)
 	 */
 	@Override
-	public Object getOrDefault(Object key, Object defaultValue) {
+	public Object getOrDefault(@Nullable Object key, @Nullable Object defaultValue) {
 		return documentAsMap.getOrDefault(key, defaultValue);
 	}
 
@@ -251,7 +251,7 @@ class MapDocument implements Document {
 	 * @see java.util.Map#put(java.lang.Object, java.lang.Object)
 	 */
 	@Override
-	public Object put(String key, Object value) {
+	public Object put(String key, @Nullable Object value) {
 		return documentAsMap.put(key, value);
 	}
 
@@ -260,7 +260,7 @@ class MapDocument implements Document {
 	 * @see java.util.Map#remove(java.lang.Object)
 	 */
 	@Override
-	public Object remove(Object key) {
+	public Object remove(@Nullable Object key) {
 		return documentAsMap.remove(key);
 	}
 
@@ -314,7 +314,7 @@ class MapDocument implements Document {
 	 * @see java.lang.Object#equals(java.lang.Object)
 	 */
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		return documentAsMap.equals(o);
 	}
 
@@ -332,7 +332,8 @@ class MapDocument implements Document {
 	 * @see java.util.Map#forEach(java.util.function.BiConsumer)
 	 */
 	@Override
-	public void forEach(BiConsumer<? super String, ? super Object> action) {
+	public void forEach(
+			@SuppressWarnings("NullableProblems") BiConsumer<? super String, ? super @Nullable Object> action) {
 		documentAsMap.forEach(action);
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/document/SearchDocument.java

@@ -41,7 +41,7 @@ public interface SearchDocument extends Document {
 	/**
 	 * @return the fields for the search result, not {@literal null}
 	 */
-	Map<String, List<Object>> getFields();
+	Map<String, List<@Nullable Object>> getFields();
 
 	/**
 	 * The first value of the given field.
@@ -50,7 +50,7 @@ public interface SearchDocument extends Document {
 	 */
 	@Nullable
 	default <V> V getFieldValue(final String name) {
-		List<Object> values = getFields().get(name);
+		List<@Nullable Object> values = getFields().get(name);
 		if (values == null || values.isEmpty()) {
 			return null;
 		}
@@ -64,7 +64,7 @@ public interface SearchDocument extends Document {
 	 */
 	@Nullable
 	default <V> List<V> getFieldValues(final String name) {
-		List<Object> values = getFields().get(name);
+		List<@Nullable Object> values = getFields().get(name);
 		if (values == null) {
 			return null;
 		}
@@ -74,8 +74,7 @@ public interface SearchDocument extends Document {
 	/**
 	 * @return the sort values for the search hit
 	 */
-	@Nullable
-	default Object[] getSortValues() {
+	default Object @Nullable [] getSortValues() {
 		return null;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/document/SearchDocumentAdapter.java

@@ -35,7 +35,7 @@ public class SearchDocumentAdapter implements SearchDocument {
 
 	private final float score;
 	private final Object[] sortValues;
-	private final Map<String, List<Object>> fields = new HashMap<>();
+	private final Map<String, List<@Nullable Object>> fields = new HashMap<>();
 	private final Document delegate;
 	private final Map<String, List<String>> highlightFields = new HashMap<>();
 	private final Map<String, SearchDocumentResponse> innerHits = new HashMap<>();
@@ -44,9 +44,11 @@ public class SearchDocumentAdapter implements SearchDocument {
 	@Nullable private final Map<String, Double> matchedQueries;
 	@Nullable private final String routing;
 
-	public SearchDocumentAdapter(Document delegate, float score, Object[] sortValues, Map<String, List<Object>> fields,
+	public SearchDocumentAdapter(Document delegate, float score, Object[] sortValues,
+			Map<String, List<@Nullable Object>> fields,
 			Map<String, List<String>> highlightFields, Map<String, SearchDocumentResponse> innerHits,
-			@Nullable NestedMetaData nestedMetaData, @Nullable Explanation explanation, @Nullable Map<String, Double> matchedQueries,
+			@Nullable NestedMetaData nestedMetaData, @Nullable Explanation explanation,
+			@Nullable Map<String, Double> matchedQueries,
 			@Nullable String routing) {
 
 		this.delegate = delegate;
@@ -74,7 +76,7 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public Map<String, List<Object>> getFields() {
+	public Map<String, List<@Nullable Object>> getFields() {
 		return fields;
 	}
 
@@ -186,17 +188,17 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public boolean containsKey(Object key) {
+	public boolean containsKey(@Nullable Object key) {
 		return delegate.containsKey(key);
 	}
 
 	@Override
-	public boolean containsValue(Object value) {
+	public boolean containsValue(@Nullable Object value) {
 		return delegate.containsValue(value);
 	}
 
 	@Override
-	public Object get(Object key) {
+	public Object get(@Nullable Object key) {
 
 		if (delegate.containsKey(key)) {
 			return delegate.get(key);
@@ -207,12 +209,12 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public Object put(String key, Object value) {
+	public @Nullable Object put(String key, @Nullable Object value) {
 		return delegate.put(key, value);
 	}
 
 	@Override
-	public Object remove(Object key) {
+	public Object remove(@Nullable Object key) {
 		return delegate.remove(key);
 	}
 
@@ -232,12 +234,12 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public Collection<Object> values() {
+	public Collection<@Nullable Object> values() {
 		return delegate.values();
 	}
 
 	@Override
-	public Set<Entry<String, Object>> entrySet() {
+	public Set<Entry<String, @Nullable Object>> entrySet() {
 		return delegate.entrySet();
 	}
 
@@ -254,7 +256,7 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o) {
 			return true;
 		}
@@ -270,17 +272,17 @@ public class SearchDocumentAdapter implements SearchDocument {
 	}
 
 	@Override
-	public void forEach(BiConsumer<? super String, ? super Object> action) {
+	public void forEach(@Nullable BiConsumer<? super String, ? super @Nullable Object> action) {
 		delegate.forEach(action);
 	}
 
 	@Override
-	public boolean remove(Object key, Object value) {
+	public boolean remove(@Nullable Object key, @Nullable Object value) {
 		return delegate.remove(key, value);
 	}
 
 	@Override
-	public String getRouting() {
+	public @Nullable String getRouting() {
 		return routing;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/document/package-info.java

@@ -1,5 +1,18 @@
-/**
- * Classes related to the Document structure of Elasticsearch documents and search responses.
+/*
+ * Copyright 2022-present 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.
  */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.document;

src/main/java/org/springframework/data/elasticsearch/core/event/AfterLoadCallback.java

@@ -31,10 +31,11 @@ import org.springframework.data.mapping.callback.EntityCallback;
 public interface AfterLoadCallback<T> extends EntityCallback<Document> {
 
 	/**
-	 * Entity callback method invoked after a domain object is materialized from a {@link Document}. Can return either the
-	 * same or a modified instance of the {@link Document} object.
+	 * Entity callback method invoked after a {@link Document} is read from Elasticsearch. Can return either the same or a
+	 * modified instance of the {@link Document} object.
 	 *
 	 * @param document the document.
+	 * @param type the type into which the document will be converted
 	 * @param indexCoordinates of the index the document was read from.
 	 * @return a possible modified or new {@link Document}.
 	 */

src/main/java/org/springframework/data/elasticsearch/core/event/package-info.java

@@ -1,5 +1,18 @@
-/**
- * classes and interfaces related to Spring Data Elasticsearch events and callbacks.
+/*
+ * Copyright 2022-present 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.
  */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.event;

src/main/java/org/springframework/data/elasticsearch/core/geo/CustomGeoModule.java

@@ -8,18 +8,27 @@ import tools.jackson.databind.SerializationContext;
 import tools.jackson.databind.ValueDeserializer;
 import tools.jackson.databind.ValueSerializer;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
+import org.springframework.util.Assert;
 
 class PointSerializer extends ValueSerializer<Point> {
 	@Override
-	public void serialize(Point value, JsonGenerator gen, SerializationContext serializers) throws JacksonException {
+	public void serialize(Point value, @Nullable JsonGenerator gen, @Nullable SerializationContext serializers)
+			throws JacksonException {
+
+		Assert.notNull(gen, "gen must not be null");
+
 		gen.writePOJO(GeoPoint.fromPoint(value));
 	}
 }
 
 class PointDeserializer extends ValueDeserializer<Point> {
 	@Override
-	public Point deserialize(JsonParser p, DeserializationContext context) throws JacksonException {
+	public Point deserialize(@Nullable JsonParser p, @Nullable DeserializationContext context) throws JacksonException {
+
+		Assert.notNull(p, "p must not be null");
+
 		return GeoPoint.toPoint(p.readValueAs(GeoPoint.class));
 	}
 }

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonGeometryCollection.java

@@ -19,6 +19,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -68,7 +69,7 @@ public class GeoJsonGeometryCollection implements GeoJson<Iterable<GeoJson<?>>>
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonLineString.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 import org.springframework.util.Assert;
 
@@ -122,7 +123,7 @@ public class GeoJsonLineString implements GeoJson<Iterable<Point>> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonMultiLineString.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 import org.springframework.util.Assert;
 
@@ -81,7 +82,7 @@ public class GeoJsonMultiLineString implements GeoJson<Iterable<GeoJsonLineStrin
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonMultiPoint.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 import org.springframework.util.Assert;
 
@@ -122,7 +123,7 @@ public class GeoJsonMultiPoint implements GeoJson<Iterable<Point>> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonMultiPolygon.java

@@ -19,6 +19,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -62,7 +63,7 @@ public class GeoJsonMultiPolygon implements GeoJson<Iterable<GeoJsonPolygon>> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonPoint.java

@@ -18,6 +18,7 @@ package org.springframework.data.elasticsearch.core.geo;
 import java.util.Arrays;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 
 /**
@@ -89,7 +90,7 @@ public class GeoJsonPoint implements GeoJson<List<Double>> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoJsonPolygon.java

@@ -21,6 +21,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 import org.springframework.util.Assert;
 
@@ -207,7 +208,7 @@ public class GeoJsonPolygon implements GeoJson<Iterable<GeoJsonLineString>> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/GeoPoint.java

@@ -17,6 +17,7 @@ package org.springframework.data.elasticsearch.core.geo;
 
 import java.util.Objects;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.geo.Point;
 
 /**
@@ -63,7 +64,7 @@ public class GeoPoint {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())

src/main/java/org/springframework/data/elasticsearch/core/geo/package-info.java

@@ -1,2 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.geo;

src/main/java/org/springframework/data/elasticsearch/core/index/AliasActionParameters.java

@@ -27,7 +27,7 @@ import org.springframework.util.Assert;
  */
 public class AliasActionParameters {
 	private final String[] indices;
-	@Nullable private final String[] aliases;
+	private final String @Nullable [] aliases;
 	@Nullable private final Query filterQuery;
 	@Nullable private final Class<?> filterQueryClass;
 	@Nullable private final Boolean isHidden;
@@ -36,7 +36,7 @@ public class AliasActionParameters {
 	@Nullable private final String indexRouting;
 	@Nullable private final String searchRouting;
 
-	private AliasActionParameters(String[] indices, @Nullable String[] aliases, @Nullable Boolean isHidden,
+	private AliasActionParameters(String[] indices, String @Nullable [] aliases, @Nullable Boolean isHidden,
 			@Nullable Boolean isWriteIndex, @Nullable String routing, @Nullable String indexRouting,
 			@Nullable String searchRouting, @Nullable Query filterQuery, @Nullable Class<?> filterQueryClass) {
 		this.indices = indices;
@@ -66,7 +66,7 @@ public class AliasActionParameters {
 		return indices;
 	}
 
-	public String@Nullable[] getAliases() {
+	public String @Nullable [] getAliases() {
 		return aliases;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/index/AliasActions.java

@@ -38,7 +38,7 @@ public class AliasActions {
 	 *
 	 * @param actions {@link AliasAction} elements
 	 */
-	public AliasActions(@Nullable AliasAction... actions) {
+	public AliasActions(AliasAction @Nullable... actions) {
 		add(actions);
 	}
 
@@ -52,10 +52,9 @@ public class AliasActions {
 	 * @param actions elements to add
 	 * @return this object
 	 */
-	public AliasActions add(@Nullable AliasAction... actions) {
+	public AliasActions add(AliasAction @Nullable... actions) {
 
 		if (actions != null) {
-			// noinspection NullableProblems
 			this.actions.addAll(Arrays.asList(actions));
 		}
 

src/main/java/org/springframework/data/elasticsearch/core/index/ComponentTemplateRequestData.java

@@ -40,7 +40,7 @@ public record ComponentTemplateRequestData(@Nullable Settings settings, @Nullabl
 		@Nullable private AliasActions aliasActions;
 		@Nullable private Boolean allowAutoCreate;
 
-		public Builder withSettings(Map<String, Object> settings) {
+		public Builder withSettings(Map<String, @Nullable Object> settings) {
 			this.settings = new Settings(settings);
 			return this;
 		}

src/main/java/org/springframework/data/elasticsearch/core/index/IndexOptionMapper.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2026-present 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.elasticsearch.core.index;
+
+import tools.jackson.databind.node.ObjectNode;
+
+import org.springframework.data.elasticsearch.annotations.CustomIndexOption;
+
+/**
+ * Writes the particular instance of the {@code CustomIndexOption} into the mapping, represented by objectNode.
+ *
+ * @author Andriy Redko
+ * @since 6.2
+ */
+public interface IndexOptionMapper {
+	void writeIndexOptionTo(CustomIndexOption indexOption, ObjectNode objectNode);
+}

src/main/java/org/springframework/data/elasticsearch/core/index/IndexOptionMappers.java

@@ -0,0 +1,301 @@
+/*
+ * Copyright 2026-present 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.elasticsearch.core.index;
+
+import tools.jackson.databind.JsonNode;
+import tools.jackson.databind.node.ArrayNode;
+import tools.jackson.databind.node.BigIntegerNode;
+import tools.jackson.databind.node.BooleanNode;
+import tools.jackson.databind.node.DecimalNode;
+import tools.jackson.databind.node.NullNode;
+import tools.jackson.databind.node.ObjectNode;
+import tools.jackson.databind.node.StringNode;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.Objects;
+
+import org.jspecify.annotations.Nullable;
+import org.springframework.data.elasticsearch.annotations.CustomIndexOption;
+
+/**
+ * The collection of predefined {@link IndexOptionMapper}s
+ *
+ * @author Andriy Redko
+ * @since 6.2
+ */
+public final class IndexOptionMappers {
+	private IndexOptionMappers() {}
+
+	/**
+	 * Writes the {@link CustomIndexOption} instance into mapping as JSON string (or array of strings) property
+	 */
+	public static final class StringMapper implements IndexOptionMapper {
+		@Override
+		public void writeIndexOptionTo(CustomIndexOption indexOption, ObjectNode objectNode) {
+			final String[] values = Objects.requireNonNull(indexOption.values(), "Values are required");
+
+			if (values.length == 1) {
+				writePropertyAsString(indexOption.name(), indexOption.overrideIfPresent(), values[0], objectNode);
+			} else if (values.length > 1) {
+				writePropertyAsArray(indexOption.name(), indexOption.overrideIfPresent(), values, objectNode);
+			} else {
+				removeProperty(indexOption.name(), objectNode);
+			}
+		}
+	}
+
+	/**
+	 * Writes the {@link CustomIndexOption} instance into mapping as JSON number (or array of numbers) property
+	 */
+	public static final class NumberMapper implements IndexOptionMapper {
+		@Override
+		public void writeIndexOptionTo(CustomIndexOption indexOption, ObjectNode objectNode) {
+			final @Nullable Number[] values = toNumbers(Objects.requireNonNull(indexOption.values(), "Values are required"));
+
+			if (values.length == 1) {
+				writePropertyAsNumber(indexOption.name(), indexOption.overrideIfPresent(), values[0], objectNode);
+			} else if (values.length > 1) {
+				writePropertyAsArray(indexOption.name(), indexOption.overrideIfPresent(), values, objectNode);
+			} else {
+				removeProperty(indexOption.name(), objectNode);
+			}
+		}
+	}
+
+	/**
+	 * Writes the {@link CustomIndexOption} instance into mapping as JSON boolean (or array of booleans) property
+	 */
+	public static final class BooleanMapper implements IndexOptionMapper {
+		@Override
+		public void writeIndexOptionTo(CustomIndexOption indexOption, ObjectNode objectNode) {
+			final @Nullable Boolean[] values = toBoolean(Objects.requireNonNull(indexOption.values(), "Values are required"));
+
+			if (values.length == 1) {
+				writePropertyAsBoolean(indexOption.name(), indexOption.overrideIfPresent(), values[0], objectNode);
+			} else if (values.length > 1) {
+				writePropertyAsArray(indexOption.name(), indexOption.overrideIfPresent(), values, objectNode);
+			} else {
+				removeProperty(indexOption.name(), objectNode);
+			}
+		}
+	}
+
+	/**
+	 * Convert the array of strings to array of booleans.
+	 *
+	 * @param values array of strings
+	 * @return array of booleans
+	 */
+	private static @Nullable Boolean[] toBoolean(@Nullable String[] values) {
+		return Arrays.stream(values).map(Boolean::valueOf).toArray(Boolean[]::new);
+	}
+
+	/**
+	 * Convert the array of strings to array of numbers, throwing {@link NumberFormatException} if the conversion is not
+	 * possible.
+	 *
+	 * @param values array of strings
+	 * @return array of numbers
+	 * @throws NumberFormatException
+	 */
+	private static @Nullable Number[] toNumbers(@Nullable String[] values) {
+		final @Nullable Number[] numbers = new Number[values.length];
+
+		for (int j = 0; j < values.length; ++j) {
+			Number number = null;
+			var value = values[j];
+
+			if (value != null) {
+				try {
+					number = new BigInteger(value);
+				} catch (NumberFormatException e) {
+					number = new BigDecimal(value);
+				}
+			}
+
+			numbers[j] = number;
+		}
+
+		return numbers;
+	}
+
+	/**
+	 * Writes a property as a JSON boolean value.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param value property value
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsBoolean(String name, boolean override, @Nullable Boolean value,
+			ObjectNode objectNode) {
+		final JsonNode node = BooleanNode.valueOf(value);
+
+		if (objectNode.has(name) && override) {
+			objectNode.replace(name, node);
+		} else {
+			objectNode.putIfAbsent(name, node);
+		}
+	}
+
+	/**
+	 * Writes a property as a JSON number value.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param value property value
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsNumber(String name, boolean override, @Nullable Number value,
+			ObjectNode objectNode) {
+		final JsonNode node = toJsonNode(value);
+
+		if (objectNode.has(name) && override) {
+			objectNode.replace(name, node);
+		} else {
+			objectNode.putIfAbsent(name, node);
+		}
+	}
+
+	/**
+	 * Writes a property as a JSON string value.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param value property value
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsString(String name, boolean override, String value, ObjectNode objectNode) {
+		final StringNode node = StringNode.valueOf(value);
+
+		if (objectNode.has(name) && override) {
+			objectNode.replace(name, node);
+		} else {
+			objectNode.putIfAbsent(name, node);
+		}
+	}
+
+	/**
+	 * Removes the property if present.
+	 *
+	 * @param name property name
+	 * @param objectNode JSON object node
+	 */
+	private static void removeProperty(String name, ObjectNode objectNode) {
+		if (objectNode.has(name)) {
+			objectNode.remove(name);
+		}
+	}
+
+	/**
+	 * Writes a property as a JSON array of boolean values.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param values property values
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsArray(String name, boolean override, @Nullable Boolean[] values,
+			ObjectNode objectNode) {
+		writePropertyAsArray(
+				name,
+				override,
+				objectNode
+						.arrayNode()
+						.addAll(
+								Arrays.stream(values).map(b -> b != null ? BooleanNode.valueOf(b) : NullNode.getInstance()).toList()),
+				objectNode);
+	}
+
+	/**
+	 * Writes a property as a JSON array of number values.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param values property values
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsArray(String name, boolean override, @Nullable Number[] values,
+			ObjectNode objectNode) {
+		writePropertyAsArray(
+				name,
+				override,
+				objectNode
+						.arrayNode()
+						.addAll(Arrays.stream(values).map(IndexOptionMappers::toJsonNode).toList()),
+				objectNode);
+	}
+
+	/**
+	 * Writes a property as a JSON array of string values.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param values property values
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsArray(String name, boolean override, String[] values, ObjectNode objectNode) {
+		writePropertyAsArray(
+				name,
+				override,
+				objectNode
+						.arrayNode()
+						.addAll(Arrays.stream(values).map(StringNode::valueOf).toList()),
+				objectNode);
+	}
+
+	/**
+	 * Writes a property as a JSON array.
+	 *
+	 * @param name property name
+	 * @param override override if present
+	 * @param arrayNode JSON array
+	 * @param objectNode JSON object node
+	 */
+	private static void writePropertyAsArray(String name, boolean override, ArrayNode arrayNode, ObjectNode objectNode) {
+		if (objectNode.has(name) && override) {
+			objectNode.replace(name, arrayNode);
+		} else {
+			objectNode.putIfAbsent(name, arrayNode);
+		}
+	}
+
+	/**
+	 * Converts a number into appropriate JSON node. Only {@link DecimalNode} and {@link BigInteger} types are supported.
+	 *
+	 * @param value {@link Number} instance to convert
+	 * @throws IllegalArgumentException
+	 */
+	private static JsonNode toJsonNode(@Nullable Number value) {
+
+		if (value == null) {
+			return NullNode.getInstance();
+		}
+
+		if (value instanceof BigDecimal d) {
+			return DecimalNode.valueOf(d);
+		} else if (value instanceof BigInteger i) {
+			return BigIntegerNode.valueOf(i);
+		} else {
+			// We only support BigDecimal or BigInteger numeric values, should never happen since the
+			// conversion is constrained within this class only.
+			throw new IllegalArgumentException("Only BigDecimal or BigInteger numbers are supported");
+		}
+	}
+}

src/main/java/org/springframework/data/elasticsearch/core/index/MappingBuilder.java

@@ -36,9 +36,7 @@ import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
-
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.core.TypeInformation;
@@ -112,9 +110,15 @@ public class MappingBuilder {
 
 	protected final ElasticsearchConverter elasticsearchConverter;
 	private final ObjectMapper objectMapper = new ObjectMapper();
+	private final MappingParametersCustomizer customizer;
 
 	public MappingBuilder(ElasticsearchConverter elasticsearchConverter) {
+		this(elasticsearchConverter, MappingParameters::from);
+	}
+
+	public MappingBuilder(ElasticsearchConverter elasticsearchConverter, MappingParametersCustomizer customizer) {
 		this.elasticsearchConverter = elasticsearchConverter;
+		this.customizer = customizer;
 	}
 
 	/**
@@ -275,7 +279,7 @@ public class MappingBuilder {
 			writeTypeHintMapping(propertiesNode);
 
 			if (entity != null) {
-				entity.doWithProperties((PropertyHandler<@NonNull ElasticsearchPersistentProperty>) property -> {
+				entity.doWithProperties((PropertyHandler<ElasticsearchPersistentProperty>) property -> {
 					try {
 						if (property.isAnnotationPresent(Transient.class) || isInIgnoreFields(property, parentFieldAnnotation)) {
 							return;
@@ -589,7 +593,7 @@ public class MappingBuilder {
 		private void addFieldMappingParameters(ObjectNode fieldNode, Annotation annotation, boolean nestedOrObjectField)
 				throws IOException {
 
-			MappingParameters mappingParameters = MappingParameters.from(annotation);
+			MappingParameters mappingParameters = customizer.from(annotation);
 
 			if (!nestedOrObjectField && mappingParameters.isStore()) {
 				fieldNode.put(FIELD_PARAM_STORE, true);

src/main/java/org/springframework/data/elasticsearch/core/index/MappingParameters.java

@@ -27,6 +27,7 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 import org.jspecify.annotations.Nullable;
+import org.springframework.beans.BeanUtils;
 import org.springframework.data.elasticsearch.annotations.*;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -34,7 +35,9 @@ import org.springframework.util.StringUtils;
 /**
  * A class to hold the mapping parameters that might be set on
  * {@link org.springframework.data.elasticsearch.annotations.Field } or
- * {@link org.springframework.data.elasticsearch.annotations.InnerField} annotation.
+ * {@link org.springframework.data.elasticsearch.annotations.InnerField} annotation. The class allows extensibility
+ * (non-final) to simplify mapping parameters customization, provided by
+ * {@link org.springframework.data.elasticsearch.core.index.MappingParametersCustomizer}.
  *
  * @author Peter-Josef Meisch
  * @author Aleksei Arsenev
@@ -42,9 +45,10 @@ import org.springframework.util.StringUtils;
  * @author Morgan Lutz
  * @author Sascha Woo
  * @author Haibo Liu
+ * @author Andriy Redko
  * @since 4.0
  */
-public final class MappingParameters {
+public class MappingParameters {
 
 	static final String FIELD_PARAM_COERCE = "coerce";
 	static final String FIELD_PARAM_COPY_TO = "copy_to";
@@ -86,7 +90,7 @@ public final class MappingParameters {
 
 	private final String analyzer;
 	private final boolean coerce;
-	@Nullable private final String[] copyTo;
+	private final String @Nullable [] copyTo;
 	private final DateFormat[] dateFormats;
 	private final String[] dateFormatPatterns;
 	private final boolean docValues;
@@ -117,6 +121,7 @@ public final class MappingParameters {
 	private final TermVector termVector;
 	private final FieldType type;
 	private final String mappedTypeName;
+	private final CustomIndexOption[] customIndexOptions;
 
 	/**
 	 * extracts the mapping parameters from the relevant annotations.
@@ -137,7 +142,7 @@ public final class MappingParameters {
 		}
 	}
 
-	private MappingParameters(Field field) {
+	protected MappingParameters(Field field) {
 		index = field.index();
 		store = field.store();
 		fielddata = field.fielddata();
@@ -182,9 +187,10 @@ public final class MappingParameters {
 		Assert.isTrue(field.enabled() || type == FieldType.Object, "enabled false is only allowed for field type object");
 		enabled = field.enabled();
 		eagerGlobalOrdinals = field.eagerGlobalOrdinals();
+		customIndexOptions = field.customIndexOptions();
 	}
 
-	private MappingParameters(InnerField field) {
+	protected MappingParameters(InnerField field) {
 		index = field.index();
 		store = field.store();
 		fielddata = field.fielddata();
@@ -228,6 +234,7 @@ public final class MappingParameters {
 		knnIndexOptions = field.knnIndexOptions().length > 0 ? field.knnIndexOptions()[0] : null;
 		enabled = true;
 		eagerGlobalOrdinals = field.eagerGlobalOrdinals();
+		customIndexOptions = field.customIndexOptions();
 	}
 
 	public boolean isStore() {
@@ -416,5 +423,143 @@ public final class MappingParameters {
 		if (eagerGlobalOrdinals) {
 			objectNode.put(FIELD_PARAM_EAGER_GLOBAL_ORDINALS, eagerGlobalOrdinals);
 		}
+		
+		// At last, check the custom index options
+		for (CustomIndexOption customIndexOption: customIndexOptions) {
+			final IndexOptionMapper mapper = BeanUtils.instantiateClass(customIndexOption.mapper());
+		    mapper.writeIndexOptionTo(customIndexOption, objectNode);
+		}
+	}
+
+	protected String analyzer() {
+		return analyzer;
+	}
+
+	protected boolean coerce() {
+		return coerce;
+	}
+
+	protected String @Nullable [] copyTo() {
+		return copyTo;
+	}
+
+	protected DateFormat[] dateFormats() {
+		return dateFormats;
+	}
+
+	protected String[] dateFormatPatterns() {
+		return dateFormatPatterns;
+	}
+
+	protected boolean hasDocValues() {
+		return docValues;
+	}
+
+	protected boolean hasEagerGlobalOrdinals() {
+		return eagerGlobalOrdinals;
+	}
+
+	protected boolean isEnabled() {
+		return enabled;
+	}
+
+	protected boolean hasFielddata() {
+		return fielddata;
+	}
+
+	protected Integer ignoreAbove() {
+		return ignoreAbove;
+	}
+
+	protected boolean isIgnoreMalformed() {
+		return ignoreMalformed;
+	}
+
+	protected boolean isIndex() {
+		return index;
+	}
+
+	protected IndexOptions indexOptions() {
+		return indexOptions;
+	}
+
+	protected boolean isIndexPhrases() {
+		return indexPhrases;
+	}
+
+	protected IndexPrefixes indexPrefixes() {
+		return indexPrefixes;
+	}
+
+	protected String normalizer() {
+		return normalizer;
+	}
+
+	protected boolean hasNorms() {
+		return norms;
+	}
+
+	protected Integer maxShingleSize() {
+		return maxShingleSize;
+	}
+
+	protected String nullValue() {
+		return nullValue;
+	}
+
+	protected NullValueType nullValueType() {
+		return nullValueType;
+	}
+
+	protected Integer positionIncrementGap() {
+		return positionIncrementGap;
+	}
+
+	protected boolean positiveScoreImpact() {
+		return positiveScoreImpact;
+	}
+
+	protected Integer dims() {
+		return dims;
+	}
+
+	protected String elementType() {
+		return elementType;
+	}
+
+	protected KnnSimilarity knnSimilarity() {
+		return knnSimilarity;
+	}
+
+	protected KnnIndexOptions knnIndexOptions() {
+		return knnIndexOptions;
+	}
+
+	protected String searchAnalyzer() {
+		return searchAnalyzer;
+	}
+
+	protected double scalingFactor() {
+		return scalingFactor;
+	}
+
+	protected String similarity() {
+		return similarity;
+	}
+
+	protected TermVector termVector() {
+		return termVector;
+	}
+
+	protected FieldType type() {
+		return type;
+	}
+
+	protected String mappedTypeName() {
+		return mappedTypeName;
+	}
+	
+	protected CustomIndexOption[] customIndexOptions() {
+		return customIndexOptions;
 	}
 }

src/main/java/org/springframework/data/elasticsearch/core/index/MappingParametersCustomizer.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2026-present 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.elasticsearch.core.index;
+
+import java.lang.annotation.Annotation;
+
+/**
+ * Allows to customize {@link org.springframework.data.elasticsearch.core.index.MappingParameters} that are being
+ * emitted for each supported annotation. Needed by dependent projects like Spring-Data-Opensearch.
+ *
+ * @author Andriy Redko
+ * @since 6.1.0
+ */
+public interface MappingParametersCustomizer {
+	/**
+	 * Customize @link org.springframework.data.elasticsearch.core.index.MappingParameters} for each supported annotation.
+	 *
+	 * @param annotation supported annotation
+	 * @return customized @link org.springframework.data.elasticsearch.core.index.MappingParameters}
+	 */
+
+	MappingParameters from(Annotation annotation);
+}

src/main/java/org/springframework/data/elasticsearch/core/index/PutTemplateRequest.java

@@ -102,7 +102,7 @@ public class PutTemplateRequest {
 			this.indexPatterns = indexPatterns;
 		}
 
-		public TemplateRequestBuilder withSettings(Map<String, Object> settings) {
+		public TemplateRequestBuilder withSettings(Map<String, @Nullable Object> settings) {
 			this.settings = new Settings(settings);
 			return this;
 		}

src/main/java/org/springframework/data/elasticsearch/core/index/ReactiveMappingBuilder.java

@@ -31,6 +31,7 @@ import org.springframework.data.mapping.MappingException;
  * Subclass of {@link MappingBuilder} with specialized methods To inhibit blocking calls
  *
  * @author Peter-Josef Meisch
+ * @author Andriy Redko
  * @since 4.3
  */
 public class ReactiveMappingBuilder extends MappingBuilder {
@@ -39,6 +40,10 @@ public class ReactiveMappingBuilder extends MappingBuilder {
 		super(elasticsearchConverter);
 	}
 
+	public ReactiveMappingBuilder(ElasticsearchConverter elasticsearchConverter, MappingParametersCustomizer customizer) {
+		super(elasticsearchConverter, customizer);
+	}
+
 	@Override
 	public String buildPropertyMapping(Class<?> clazz) throws MappingException {
 		throw new UnsupportedOperationException(

src/main/java/org/springframework/data/elasticsearch/core/index/Settings.java

@@ -21,6 +21,7 @@ import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.elasticsearch.support.DefaultStringObjectMap;
 import org.springframework.util.Assert;
 
@@ -34,7 +35,7 @@ public class Settings extends DefaultStringObjectMap<Settings> {
 
 	public Settings() {}
 
-	public Settings(Map<String, Object> map) {
+	public Settings(Map<String, @Nullable Object> map) {
 		super(map);
 	}
 
@@ -54,7 +55,7 @@ public class Settings extends DefaultStringObjectMap<Settings> {
 	}
 
 	@Override
-	public Object get(Object key) {
+	public Object get(@Nullable Object key) {
 		return containsKey(key) ? super.get(key) : path(key.toString());
 	}
 
@@ -75,11 +76,11 @@ public class Settings extends DefaultStringObjectMap<Settings> {
 	 * taken from https://stackoverflow.com/a/29698326/4393565
 	 */
 	@SuppressWarnings("unchecked")
-	private static Map<?, ?> deepMerge(Map<String, Object> original, Map<String, Object> newMap) {
+	private static Map<?, ?> deepMerge(Map<String, @Nullable Object> original, Map<String, @Nullable Object> newMap) {
 		for (Object key : newMap.keySet()) {
 			if (newMap.get(key) instanceof Map && original.get(key) instanceof Map) {
-				Map<String, Object> originalChild = (Map<String, Object>) original.get(key);
-				Map<String, Object> newChild = (Map<String, Object>) newMap.get(key);
+				Map<String, @Nullable Object> originalChild = (Map<String, Object>) original.get(key);
+				Map<String, @Nullable Object> newChild = (Map<String, Object>) newMap.get(key);
 				original.put(key.toString(), deepMerge(originalChild, newChild));
 			} else if (newMap.get(key) instanceof List && original.get(key) instanceof List) {
 				List<Object> originalChild = (List<Object>) original.get(key);
@@ -112,9 +113,9 @@ public class Settings extends DefaultStringObjectMap<Settings> {
 	 * flattens a Map<String, Object> to a stream of Map.Entry objects where the keys are the dot separated concatenated
 	 * keys of sub map entries
 	 */
-	static private Stream<Map.Entry<String, Object>> doFlatten(Map.Entry<String, Object> entry) {
+	static private Stream<Map.Entry<String, @Nullable Object>> doFlatten(Map.Entry<String, @Nullable Object> entry) {
 
-		if (entry.getValue()instanceof Map<?, ?> nested) {
+		if (entry.getValue() instanceof Map<?, ?> nested) {
 
 			// noinspection unchecked
 			return nested.entrySet().stream() //

src/main/java/org/springframework/data/elasticsearch/core/index/TemplateData.java

@@ -91,7 +91,7 @@ public class TemplateData {
 			return this;
 		}
 
-		public TemplateDataBuilder withSettings(Map<String, Object> settings) {
+		public TemplateDataBuilder withSettings(Map<String, @Nullable Object> settings) {
 			this.settings = new Settings(settings);
 			return this;
 		}

src/main/java/org/springframework/data/elasticsearch/core/index/package-info.java

@@ -1,5 +1,18 @@
-/**
- * Classes related to Elasticsearch index management.
+/*
+ * Copyright 2022-present 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.
  */
+
 @org.jspecify.annotations.NullMarked
 package org.springframework.data.elasticsearch.core.index;

src/main/java/org/springframework/data/elasticsearch/core/join/JoinField.java

@@ -64,7 +64,7 @@ public class JoinField<ID> {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

src/main/java/org/springframework/data/elasticsearch/core/join/package-info.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2022-present 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.
+ */
+
+@org.jspecify.annotations.NullMarked
+package org.springframework.data.elasticsearch.core.join;

src/main/java/org/springframework/data/elasticsearch/core/mapping/Alias.java

@@ -115,7 +115,7 @@ public class Alias {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (!(o instanceof Alias that))

src/main/java/org/springframework/data/elasticsearch/core/mapping/CreateIndexSettings.java

@@ -33,7 +33,7 @@ public class CreateIndexSettings {
 	private final IndexCoordinates indexCoordinates;
 	private final Set<Alias> aliases;
 
-	@Nullable private final Map<String, Object> settings;
+	@Nullable private final Map<String, @Nullable Object> settings;
 
 	@Nullable private final Document mapping;
 
@@ -58,7 +58,7 @@ public class CreateIndexSettings {
 	}
 
 	@Nullable
-	public Map<String, Object> getSettings() {
+	public Map<String, @Nullable Object> getSettings() {
 		return settings;
 	}
 
@@ -71,7 +71,7 @@ public class CreateIndexSettings {
 		private final IndexCoordinates indexCoordinates;
 		private final Set<Alias> aliases = new HashSet<>();
 
-		@Nullable private Map<String, Object> settings;
+		@Nullable private Map<String, @Nullable Object> settings;
 
 		@Nullable private Document mapping;
 
@@ -94,7 +94,7 @@ public class CreateIndexSettings {
 			return this;
 		}
 
-		public Builder withSettings(Map<String, Object> settings) {
+		public Builder withSettings(Map<String, @Nullable Object> settings) {
 			Assert.notNull(settings, "settings must not be null");
 			this.settings = settings;
 

src/main/java/org/springframework/data/elasticsearch/core/mapping/ElasticsearchPersistentEntity.java

@@ -21,6 +21,7 @@ import org.jspecify.annotations.Nullable;
 import org.springframework.data.elasticsearch.annotations.Document;
 import org.springframework.data.elasticsearch.annotations.Dynamic;
 import org.springframework.data.elasticsearch.annotations.Field;
+import org.springframework.data.elasticsearch.config.ElasticsearchServerType;
 import org.springframework.data.elasticsearch.core.index.Settings;
 import org.springframework.data.elasticsearch.core.join.JoinField;
 import org.springframework.data.elasticsearch.core.query.SeqNoPrimaryTerm;
@@ -39,6 +40,7 @@ import org.springframework.data.mapping.model.FieldNamingStrategy;
  * @author Peter-Josef Meisch
  * @author Roman Puchkovskiy
  * @author Subhobrata Dey
+ * @author Steven Pearce
  */
 public interface ElasticsearchPersistentEntity<T> extends PersistentEntity<T, ElasticsearchPersistentProperty> {
 
@@ -179,6 +181,12 @@ public interface ElasticsearchPersistentEntity<T> extends PersistentEntity<T, El
 	 */
 	boolean writeTypeHints();
 
+	/**
+	 * @return the {@link ElasticsearchServerType} for the server that stores this entity
+	 * @since 6.2
+	 */
+	ElasticsearchServerType getServerType();
+
 	/**
 	 * @return the {@code dynamic} mapping parameter value.
 	 * @since 4.3

src/main/java/org/springframework/data/elasticsearch/core/mapping/IndexCoordinates.java

@@ -17,6 +17,7 @@ package org.springframework.data.elasticsearch.core.mapping;
 
 import java.util.Arrays;
 
+import org.jspecify.annotations.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -55,7 +56,7 @@ public class IndexCoordinates {
 	 * @since 4.2
 	 */
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		if (this == o)
 			return true;
 		if (o == null || getClass() != o.getClass())