Adapt Kotlin null-safety with Spring Framework changes

Closes gh-47428

.github/actions/prepare-gradle-build/action.yml

@@ -23,7 +23,7 @@ inputs:
   java-version:
     description: 'Java version to use for the build'
     required: false
-    default: '24'
+    default: '25'
 runs:
   using: composite
   steps:
@@ -42,12 +42,12 @@ runs:
           ${{ inputs.java-toolchain == 'true' && '24' || '' }}
     - name: Set Up Gradle With Read/Write Cache
       if: ${{ inputs.cache-read-only == 'false' }}
-      uses: gradle/actions/setup-gradle@ed408507eac070d1f99cc633dbcf757c94c7933a # v4.4.3
+      uses: gradle/actions/setup-gradle@748248ddd2a24f49513d8f472f81c3a07d4d50e1 # v4.4.4
       with:
         cache-read-only: false
         develocity-access-key: ${{ inputs.develocity-access-key }}
     - name: Set Up Gradle
-      uses: gradle/actions/setup-gradle@ed408507eac070d1f99cc633dbcf757c94c7933a # v4.4.3
+      uses: gradle/actions/setup-gradle@748248ddd2a24f49513d8f472f81c3a07d4d50e1 # v4.4.4
       with:
         develocity-access-key: ${{ inputs.develocity-access-key }}
         develocity-token-expiry: 4

.github/actions/publish-gradle-plugin/action.yml

@@ -21,7 +21,7 @@ runs:
   using: composite
   steps:
     - name: Set Up JFrog CLI
-      uses: jfrog/setup-jfrog-cli@88e9eba31c07e31beefa4cef5c0e93d1af9535d7 # v4.6.1
+      uses: jfrog/setup-jfrog-cli@c32bf10843e4071112c4ea3abf622d3b27cd8c17 # v4.7.0
       env:
         JF_ENV_SPRING: ${{ inputs.jfrog-cli-config-token }}
     - name: Download Artifacts

.github/actions/sync-to-maven-central/action.yml

@@ -17,7 +17,7 @@ runs:
   using: composite
   steps:
     - name: Set Up JFrog CLI
-      uses: jfrog/setup-jfrog-cli@88e9eba31c07e31beefa4cef5c0e93d1af9535d7 # v4.6.1
+      uses: jfrog/setup-jfrog-cli@c32bf10843e4071112c4ea3abf622d3b27cd8c17 # v4.7.0
       env:
         JF_ENV_SPRING: ${{ inputs.jfrog-cli-config-token }}
     - name: Download Release Artifacts

.github/workflows/ci.yml

@@ -23,16 +23,13 @@ jobs:
             toolchain: true
           - version: 21
             toolchain: true
-          - version: 24
-            toolchain: false
           - version: 25
-            early-access: true
-            toolchain: true
+            toolchain: false
         exclude:
           - os:
               name: Linux
             java:
-              version: 24
+              version: 25
           - os:
               name: ${{ github.repository == 'spring-projects/spring-boot-commercial' && 'Windows' }}
     steps:

.github/workflows/release-milestone.yml

@@ -75,7 +75,7 @@ jobs:
     runs-on: ${{ vars.UBUNTU_SMALL || 'ubuntu-latest' }}
     steps:
       - name: Set up JFrog CLI
-        uses: jfrog/setup-jfrog-cli@88e9eba31c07e31beefa4cef5c0e93d1af9535d7 # v4.6.1
+        uses: jfrog/setup-jfrog-cli@c32bf10843e4071112c4ea3abf622d3b27cd8c17 # v4.7.0
         env:
           JF_ENV_SPRING: ${{ secrets.JF_ARTIFACTORY_SPRING }}
       - name: Promote build

.github/workflows/release.yml

@@ -86,7 +86,7 @@ jobs:
     runs-on: ${{ vars.UBUNTU_SMALL || 'ubuntu-latest' }}
     steps:
       - name: Set up JFrog CLI
-        uses: jfrog/setup-jfrog-cli@88e9eba31c07e31beefa4cef5c0e93d1af9535d7 # v4.6.1
+        uses: jfrog/setup-jfrog-cli@c32bf10843e4071112c4ea3abf622d3b27cd8c17 # v4.7.0
         env:
           JF_ENV_SPRING: ${{ vars.COMMERCIAL && secrets.COMMERCIAL_JF_ARTIFACTORY_SPRING || secrets.JF_ARTIFACTORY_SPRING }}
       - name: Promote open source build

.github/workflows/verify.yml

@@ -59,7 +59,7 @@ jobs:
         with:
           stable: true
       - name: Set Up Gradle
-        uses: gradle/actions/setup-gradle@ed408507eac070d1f99cc633dbcf757c94c7933a # v4.4.3
+        uses: gradle/actions/setup-gradle@748248ddd2a24f49513d8f472f81c3a07d4d50e1 # v4.4.4
         with:
           cache-read-only: false
       - name: Configure Gradle Properties

.sdkmanrc

@@ -1,3 +1,3 @@
 # Enable auto-env through the sdkman_auto_env config
 # Add key=value pairs of SDKs to use below
-java=24.0.2-librca
+java=25-librca

antora/package-lock.json

@@ -14,7 +14,7 @@
         "@springio/antora-xref-extension": "1.0.0-alpha.4",
         "@springio/antora-zip-contents-collector-extension": "1.0.0-alpha.8",
         "@springio/asciidoctor-extensions": "1.0.0-alpha.17",
-        "patch-package": "^8.0.0"
+        "patch-package": "^8.0.1"
       }
     },
     "node_modules/@antora/asciidoc-loader": {
@@ -575,14 +575,6 @@
       "resolved": "https://registry.npmjs.org/async-lock/-/async-lock-1.4.1.tgz",
       "integrity": "sha512-Az2ZTpuytrtqENulXwO3GGv1Bztugx6TT37NIo7imr/Qo0gsYiGtSdBa2B6fsXhTpVZDNfu1Qn3pk531e3q+nQ=="
     },
-    "node_modules/at-least-node": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/at-least-node/-/at-least-node-1.0.0.tgz",
-      "integrity": "sha512-+q/t7Ekv1EDY2l6Gda6LLiX14rU9TV20Wa3ofeQmwPFZbOMo9DXrLbOjFaaclkXKWidIaopwAObQDqwWtGUjqg==",
-      "engines": {
-        "node": ">= 4.0.0"
-      }
-    },
     "node_modules/atomic-sleep": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/atomic-sleep/-/atomic-sleep-1.0.0.tgz",
@@ -1406,17 +1398,17 @@
       "integrity": "sha512-y6OAwoSIf7FyjMIv94u+b5rdheZEjzR63GTyZJm5qh4Bi+2YgwLCcI/fPFZkL5PSixOt6ZNKm+w+Hfp/Bciwow=="
     },
     "node_modules/fs-extra": {
-      "version": "9.1.0",
-      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-9.1.0.tgz",
-      "integrity": "sha512-hcg3ZmepS30/7BSFqRvoo3DOMQu7IjqxO5nCDt+zM9XWjb33Wg7ziNT+Qvqbuc3+gWpzO02JubVyk2G4Zvo1OQ==",
+      "version": "10.1.0",
+      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-10.1.0.tgz",
+      "integrity": "sha512-oRXApq54ETRj4eMiFzGnHWGy+zo5raudjuxN0b8H7s/RU2oW0Wvsx9O0ACRN/kRq9E8Vu/ReskGB5o3ji+FzHQ==",
+      "license": "MIT",
       "dependencies": {
-        "at-least-node": "^1.0.0",
         "graceful-fs": "^4.2.0",
         "jsonfile": "^6.0.1",
         "universalify": "^2.0.0"
       },
       "engines": {
-        "node": ">=10"
+        "node": ">=12"
       }
     },
     "node_modules/fs-mkdirp-stream": {
@@ -1993,9 +1985,10 @@
       }
     },
     "node_modules/jsonfile": {
-      "version": "6.1.0",
-      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-6.1.0.tgz",
-      "integrity": "sha512-5dgndWOriYSm5cnYaJNhalLNDKOqFwyDB/rr1E9ZsGciGvKPs8R2xYGCacuf3z6K1YKDz182fd+fY3cn3pMqXQ==",
+      "version": "6.2.0",
+      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-6.2.0.tgz",
+      "integrity": "sha512-FGuPw30AdOIUTRMC2OMRtQV+jkVj2cfPqSeWXv1NEAJ1qZ5zb1X6z1mFhbfOB/iy3ssJCD+3KuZ8r8C3uVFlAg==",
+      "license": "MIT",
       "dependencies": {
         "universalify": "^2.0.0"
       },
@@ -2331,38 +2324,30 @@
         "safe-buffer": "~5.1.0"
       }
     },
-    "node_modules/os-tmpdir": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/os-tmpdir/-/os-tmpdir-1.0.2.tgz",
-      "integrity": "sha512-D2FR03Vir7FIu45XBY20mTb+/ZSWB00sjU9jdQXt83gDrI4Ztz5Fs7/yy74g2N5SVQY4xY1qDr4rNddwYRVX0g==",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
     "node_modules/pako": {
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/pako/-/pako-1.0.11.tgz",
       "integrity": "sha512-4hLB8Py4zZce5s4yd9XzopqwVv/yGNhV1Bl8NTmCq1763HeK2+EwVTv+leGeL13Dnh2wfbqowVPXCIO0z4taYw=="
     },
     "node_modules/patch-package": {
-      "version": "8.0.0",
-      "resolved": "https://registry.npmjs.org/patch-package/-/patch-package-8.0.0.tgz",
-      "integrity": "sha512-da8BVIhzjtgScwDJ2TtKsfT5JFWz1hYoBl9rUQ1f38MC2HwnEIkK8VN3dKMKcP7P7bvvgzNDbfNHtx3MsQb5vA==",
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/patch-package/-/patch-package-8.0.1.tgz",
+      "integrity": "sha512-VsKRIA8f5uqHQ7NGhwIna6Bx6D9s/1iXlA1hthBVBEbkq+t4kXD0HHt+rJhf/Z+Ci0F/HCB2hvn0qLdLG+Qxlw==",
+      "license": "MIT",
       "dependencies": {
         "@yarnpkg/lockfile": "^1.1.0",
         "chalk": "^4.1.2",
         "ci-info": "^3.7.0",
         "cross-spawn": "^7.0.3",
         "find-yarn-workspace-root": "^2.0.0",
-        "fs-extra": "^9.0.0",
+        "fs-extra": "^10.0.0",
         "json-stable-stringify": "^1.0.2",
         "klaw-sync": "^6.0.0",
         "minimist": "^1.2.6",
         "open": "^7.4.2",
-        "rimraf": "^2.6.3",
         "semver": "^7.5.3",
         "slash": "^2.0.0",
-        "tmp": "^0.0.33",
+        "tmp": "^0.2.4",
         "yaml": "^2.2.2"
       },
       "bin": {
@@ -2750,18 +2735,6 @@
         "node": ">= 0.10"
       }
     },
-    "node_modules/rimraf": {
-      "version": "2.7.1",
-      "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-2.7.1.tgz",
-      "integrity": "sha512-uWjbaKIK3T1OSVptzX7Nl6PvQ3qAGtKEtVRjRuazjfL3Bx5eI409VZSqgND+4UNnmzLVdPj9FqFJNPqBZFve4w==",
-      "deprecated": "Rimraf versions prior to v4 are no longer supported",
-      "dependencies": {
-        "glob": "^7.1.3"
-      },
-      "bin": {
-        "rimraf": "bin.js"
-      }
-    },
     "node_modules/safe-buffer": {
       "version": "5.2.1",
       "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
@@ -3118,14 +3091,12 @@
       }
     },
     "node_modules/tmp": {
-      "version": "0.0.33",
-      "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
-      "integrity": "sha512-jRCJlojKnZ3addtTOjdIqoRuPEKBvNXcGYqzO6zWZX8KfKEpnGY5jfggJQ3EjKuu8D4bJRr0y+cYJFmYbImXGw==",
-      "dependencies": {
-        "os-tmpdir": "~1.0.2"
-      },
+      "version": "0.2.5",
+      "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.2.5.tgz",
+      "integrity": "sha512-voyz6MApa1rQGUxT3E+BK7/ROe8itEx7vD8/HEvt4xwXucvQ5G5oeEiHkmHZJuBO21RpOf+YYm9MOivj709jow==",
+      "license": "MIT",
       "engines": {
-        "node": ">=0.6.0"
+        "node": ">=14.14"
       }
     },
     "node_modules/to-absolute-glob": {
@@ -3238,6 +3209,7 @@
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/universalify/-/universalify-2.0.1.tgz",
       "integrity": "sha512-gptHNQghINnc/vTGIk0SOFGFNXw7JVrlRUtConJRlvaw6DuX0wO5Jeko9sWrMBhh+PsYAZ7oXAiOnf/UKogyiw==",
+      "license": "MIT",
       "engines": {
         "node": ">= 10.0.0"
       }

antora/package.json

@@ -12,7 +12,7 @@
     "@springio/antora-zip-contents-collector-extension": "1.0.0-alpha.8",
     "@asciidoctor/tabs": "1.0.0-beta.6",
     "@springio/asciidoctor-extensions": "1.0.0-alpha.17",
-    "patch-package": "^8.0.0"
+    "patch-package": "^8.0.1"
   },
   "config": {
     "ui-bundle-url": "https://github.com/spring-io/antora-ui-spring/releases/download/v0.4.18/ui-bundle.zip"

build-plugin/spring-boot-antlib/build.gradle

@@ -80,7 +80,6 @@ tasks.register("integrationTest") {
 					ant.propertyref(name: "ivy.class.path")
 				}
 				plainlistener()
-				file(layout.buildDirectory.dir("test-results/integrationTest")).mkdirs()
 				xmllistener(toDir: resultsDir)
 				fileset(dir: layout.buildDirectory.dir("it").get().asFile.toString(), includes: "**/build.xml")
 			}

build-plugin/spring-boot-gradle-plugin/src/docs/antora/modules/gradle-plugin/examples/running/boot-run-system-property.gradle

@@ -27,7 +27,7 @@ tasks.named("bootRun") {
 
 tasks.register("configuredSystemProperties") {
 	doLast {
-		bootRun.systemProperties.each { k, v -> 
+		bootRun.systemProperties.each { k, v ->
 			println "$k = $v"
 		}
 	}

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/ApplicationPluginAction.java

@@ -141,9 +141,13 @@ final class ApplicationPluginAction implements PluginApplicationAction {
 		}
 	}
 
-	@SuppressWarnings("deprecation")
 	private void configureFileMode(CopySpec copySpec, int mode) {
-		copySpec.setFileMode(mode);
+		try {
+			copySpec.getClass().getMethod("setFileMode", Integer.class).invoke(copySpec, Integer.valueOf(mode));
+		}
+		catch (Exception ex) {
+			throw new RuntimeException("Failed to set file mode on CopySpec", ex);
+		}
 	}
 
 }

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/JarTypeFileSpec.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.gradle.plugin;
 
 import java.io.File;
-import java.util.Collections;
 import java.util.Set;
 import java.util.jar.JarFile;
 
@@ -33,7 +32,7 @@ import org.gradle.api.specs.Spec;
  */
 class JarTypeFileSpec implements Spec<File> {
 
-	private static final Set<String> EXCLUDED_JAR_TYPES = Collections.singleton("dependencies-starter");
+	private static final Set<String> EXCLUDED_JAR_TYPES = Set.of("dependencies-starter", "development-tool");
 
 	@Override
 	public boolean isSatisfiedBy(File file) {

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/JavaPluginAction.java

@@ -285,7 +285,6 @@ final class JavaPluginAction implements PluginApplicationAction {
 	private void configureProductionRuntimeClasspathConfiguration(Project project) {
 		Configuration productionRuntimeClasspath = project.getConfigurations()
 			.create(SpringBootPlugin.PRODUCTION_RUNTIME_CLASSPATH_CONFIGURATION_NAME);
-		productionRuntimeClasspath.setVisible(false);
 		Configuration runtimeClasspath = project.getConfigurations()
 			.getByName(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
 		productionRuntimeClasspath.attributes((attributes) -> {

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/WarPluginAction.java

@@ -104,7 +104,6 @@ class WarPluginAction implements PluginApplicationAction {
 					.set(project.provider(() -> javaPluginExtension(project).getTargetCompatibility()));
 				bootWar.resolvedArtifacts(runtimeClasspath.getIncoming().getArtifacts().getResolvedArtifacts());
 			});
-		bootWarProvider.map(War::getClasspath);
 		return bootWarProvider;
 	}
 

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/aot/ProcessTestAot.java

@@ -43,7 +43,7 @@ import org.springframework.util.Assert;
  * @since 3.0.0
  */
 @CacheableTask
-public class ProcessTestAot extends AbstractAot {
+public abstract class ProcessTestAot extends AbstractAot {
 
 	private @Nullable FileCollection classpathRoots;
 

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootArchive.java

@@ -34,8 +34,6 @@ import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.Optional;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.loader.tools.LoaderImplementation;
-
 /**
  * A Spring Boot "fat" archive task.
  *
@@ -137,15 +135,6 @@ public interface BootArchive extends Task {
 	 */
 	void resolvedArtifacts(Provider<Set<ResolvedArtifactResult>> resolvedArtifacts);
 
-	/**
-	 * The loader implementation that should be used with the archive.
-	 * @return the loader implementation
-	 * @since 3.2.0
-	 */
-	@Input
-	@Optional
-	Property<LoaderImplementation> getLoaderImplementation();
-
 	/**
 	 * Returns whether the JAR tools should be included as a dependency in the layered
 	 * archive.

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootArchiveSupport.java

@@ -22,32 +22,24 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Set;
-import java.util.TreeMap;
 import java.util.function.Function;
 
 import org.gradle.api.file.ConfigurableFilePermissions;
 import org.gradle.api.file.CopySpec;
 import org.gradle.api.file.FileCopyDetails;
 import org.gradle.api.file.FileTreeElement;
-import org.gradle.api.file.RelativePath;
 import org.gradle.api.internal.file.copy.CopyAction;
-import org.gradle.api.internal.file.copy.CopyActionProcessingStream;
-import org.gradle.api.internal.file.copy.FileCopyDetailsInternal;
 import org.gradle.api.java.archives.Attributes;
 import org.gradle.api.java.archives.Manifest;
 import org.gradle.api.provider.Property;
 import org.gradle.api.specs.Spec;
 import org.gradle.api.specs.Specs;
-import org.gradle.api.tasks.WorkResult;
 import org.gradle.api.tasks.bundling.Jar;
 import org.gradle.api.tasks.util.PatternSet;
 import org.gradle.util.GradleVersion;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.loader.tools.LoaderImplementation;
-
 /**
  * Support class for implementations of {@link BootArchive}.
  *
@@ -123,13 +115,11 @@ class BootArchiveSupport {
 		return (version != null) ? version : "unknown";
 	}
 
-	CopyAction createCopyAction(Jar jar, ResolvedDependencies resolvedDependencies,
-			LoaderImplementation loaderImplementation, boolean supportsSignatureFile) {
-		return createCopyAction(jar, resolvedDependencies, loaderImplementation, supportsSignatureFile, null, null);
+	CopyAction createCopyAction(Jar jar, ResolvedDependencies resolvedDependencies, boolean supportsSignatureFile) {
+		return createCopyAction(jar, resolvedDependencies, supportsSignatureFile, null, null);
 	}
 
-	CopyAction createCopyAction(Jar jar, ResolvedDependencies resolvedDependencies,
-			LoaderImplementation loaderImplementation, boolean supportsSignatureFile,
+	CopyAction createCopyAction(Jar jar, ResolvedDependencies resolvedDependencies, boolean supportsSignatureFile,
 			@Nullable LayerResolver layerResolver, @Nullable String jarmodeToolsLocation) {
 		File output = jar.getArchiveFile().get().getAsFile();
 		Manifest manifest = jar.getManifest();
@@ -145,9 +135,8 @@ class BootArchiveSupport {
 		String encoding = jar.getMetadataCharset();
 		CopyAction action = new BootZipCopyAction(output, manifest, preserveFileTimestamps, dirPermissions,
 				filePermissions, includeDefaultLoader, jarmodeToolsLocation, requiresUnpack, exclusions, launchScript,
-				librarySpec, compressionResolver, encoding, resolvedDependencies, supportsSignatureFile, layerResolver,
-				loaderImplementation);
-		return jar.isReproducibleFileOrder() ? new ReproducibleOrderingCopyAction(action) : action;
+				librarySpec, compressionResolver, encoding, resolvedDependencies, supportsSignatureFile, layerResolver);
+		return action;
 	}
 
 	private @Nullable Integer getUnixNumericDirPermissions(CopySpec copySpec) {
@@ -164,14 +153,22 @@ class BootArchiveSupport {
 		return permissions.isPresent() ? permissions.get().toUnixNumeric() : null;
 	}
 
-	@SuppressWarnings("deprecation")
 	private @Nullable Integer getDirMode(CopySpec copySpec) {
-		return copySpec.getDirMode();
+		try {
+			return (Integer) copySpec.getClass().getMethod("getDirMode").invoke(copySpec);
+		}
+		catch (Exception ex) {
+			throw new RuntimeException("Failed to get dir mode from CopySpec", ex);
+		}
 	}
 
-	@SuppressWarnings("deprecation")
 	private @Nullable Integer getFileMode(CopySpec copySpec) {
-		return copySpec.getFileMode();
+		try {
+			return (Integer) copySpec.getClass().getMethod("getFileMode").invoke(copySpec);
+		}
+		catch (Exception ex) {
+			throw new RuntimeException("Failed to get file mode from CopySpec", ex);
+		}
 	}
 
 	private boolean isUsingDefaultLoader(Jar jar) {
@@ -234,26 +231,4 @@ class BootArchiveSupport {
 		details.setRelativePath(details.getRelativeSourcePath());
 	}
 
-	/**
-	 * {@link CopyAction} variant that sorts entries to ensure reproducible ordering.
-	 */
-	private static final class ReproducibleOrderingCopyAction implements CopyAction {
-
-		private final CopyAction delegate;
-
-		private ReproducibleOrderingCopyAction(CopyAction delegate) {
-			this.delegate = delegate;
-		}
-
-		@Override
-		public WorkResult execute(CopyActionProcessingStream stream) {
-			return this.delegate.execute((action) -> {
-				Map<RelativePath, FileCopyDetailsInternal> detailsByPath = new TreeMap<>();
-				stream.process((details) -> detailsByPath.put(details.getRelativePath(), details));
-				detailsByPath.values().forEach(action::processFile);
-			});
-		}
-
-	}
-
 }

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootJar.java

@@ -38,8 +38,6 @@ import org.gradle.api.tasks.bundling.Jar;
 import org.gradle.work.DisableCachingByDefault;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.loader.tools.LoaderImplementation;
-
 /**
  * A custom {@link Jar} task that produces a Spring Boot executable jar.
  *
@@ -145,13 +143,12 @@ public abstract class BootJar extends Jar implements BootArchive {
 
 	@Override
 	protected CopyAction createCopyAction() {
-		LoaderImplementation loaderImplementation = getLoaderImplementation().getOrElse(LoaderImplementation.DEFAULT);
 		LayerResolver layerResolver = null;
 		if (!isLayeredDisabled()) {
 			layerResolver = new LayerResolver(this.resolvedDependencies, this.layered, this::isLibrary);
 		}
 		String jarmodeToolsLocation = isIncludeJarmodeTools() ? LIB_DIRECTORY : null;
-		return this.support.createCopyAction(this, this.resolvedDependencies, loaderImplementation, true, layerResolver,
+		return this.support.createCopyAction(this, this.resolvedDependencies, true, layerResolver,
 				jarmodeToolsLocation);
 	}
 

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootWar.java

@@ -38,8 +38,6 @@ import org.gradle.api.tasks.bundling.War;
 import org.gradle.work.DisableCachingByDefault;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.loader.tools.LoaderImplementation;
-
 /**
  * A custom {@link War} task that produces a Spring Boot executable war.
  *
@@ -119,14 +117,13 @@ public abstract class BootWar extends War implements BootArchive {
 
 	@Override
 	protected CopyAction createCopyAction() {
-		LoaderImplementation loaderImplementation = getLoaderImplementation().getOrElse(LoaderImplementation.DEFAULT);
 		LayerResolver layerResolver = null;
 		if (!isLayeredDisabled()) {
 			layerResolver = new LayerResolver(this.resolvedDependencies, this.layered, this::isLibrary);
 		}
 		String jarmodeToolsLocation = isIncludeJarmodeTools() ? LIB_DIRECTORY : null;
-		return this.support.createCopyAction(this, this.resolvedDependencies, loaderImplementation, false,
-				layerResolver, jarmodeToolsLocation);
+		return this.support.createCopyAction(this, this.resolvedDependencies, false, layerResolver,
+				jarmodeToolsLocation);
 	}
 
 	private boolean isIncludeJarmodeTools() {

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootZipCopyAction.java

@@ -23,13 +23,10 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.HexFormat;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -63,7 +60,6 @@ import org.springframework.boot.loader.tools.JarModeLibrary;
 import org.springframework.boot.loader.tools.Layer;
 import org.springframework.boot.loader.tools.LayersIndex;
 import org.springframework.boot.loader.tools.LibraryCoordinates;
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.boot.loader.tools.NativeImageArgFile;
 import org.springframework.boot.loader.tools.ReachabilityMetadataProperties;
 import org.springframework.util.Assert;
@@ -120,15 +116,13 @@ class BootZipCopyAction implements CopyAction {
 
 	private final @Nullable LayerResolver layerResolver;
 
-	private final LoaderImplementation loaderImplementation;
-
 	BootZipCopyAction(File output, Manifest manifest, boolean preserveFileTimestamps, @Nullable Integer dirMode,
 			@Nullable Integer fileMode, boolean includeDefaultLoader, @Nullable String jarmodeToolsLocation,
 			Spec<FileTreeElement> requiresUnpack, Spec<FileTreeElement> exclusions,
 			@Nullable LaunchScriptConfiguration launchScript, Spec<FileCopyDetails> librarySpec,
 			Function<FileCopyDetails, ZipCompression> compressionResolver, @Nullable String encoding,
 			ResolvedDependencies resolvedDependencies, boolean supportsSignatureFile,
-			@Nullable LayerResolver layerResolver, LoaderImplementation loaderImplementation) {
+			@Nullable LayerResolver layerResolver) {
 		this.output = output;
 		this.manifest = manifest;
 		this.preserveFileTimestamps = preserveFileTimestamps;
@@ -145,7 +139,6 @@ class BootZipCopyAction implements CopyAction {
 		this.resolvedDependencies = resolvedDependencies;
 		this.supportsSignatureFile = supportsSignatureFile;
 		this.layerResolver = layerResolver;
-		this.loaderImplementation = loaderImplementation;
 	}
 
 	@Override
@@ -329,8 +322,7 @@ class BootZipCopyAction implements CopyAction {
 				// Always write loader entries after META-INF directory (see gh-16698)
 				return;
 			}
-			LoaderZipEntries loaderEntries = new LoaderZipEntries(getTime(), getDirMode(), getFileMode(),
-					BootZipCopyAction.this.loaderImplementation);
+			LoaderZipEntries loaderEntries = new LoaderZipEntries(getTime(), getDirMode(), getFileMode());
 			this.writtenLoaderEntries = loaderEntries.writeTo(this.out);
 			if (BootZipCopyAction.this.layerResolver != null) {
 				for (String name : this.writtenLoaderEntries.getFiles()) {
@@ -512,9 +504,13 @@ class BootZipCopyAction implements CopyAction {
 					? details.getPermissions().toUnixNumeric() : getMode(details);
 		}
 
-		@SuppressWarnings("deprecation")
 		private int getMode(FileCopyDetails details) {
-			return details.getMode();
+			try {
+				return (int) details.getClass().getMethod("getMode").invoke(details);
+			}
+			catch (Exception ex) {
+				throw new RuntimeException("Failed to get mode from FileCopyDetails", ex);
+			}
 		}
 
 	}
@@ -590,36 +586,24 @@ class BootZipCopyAction implements CopyAction {
 
 		private static final int BUFFER_SIZE = 32 * 1024;
 
-		private final @Nullable MessageDigest messageDigest;
+		private final boolean unpack;
 
 		private final CRC32 crc = new CRC32();
 
 		private long size;
 
 		StoredEntryPreparator(InputStream inputStream, boolean unpack) throws IOException {
-			this.messageDigest = (unpack) ? sha1Digest() : null;
+			this.unpack = unpack;
 			try (inputStream) {
 				load(inputStream);
 			}
 		}
 
-		private static MessageDigest sha1Digest() {
-			try {
-				return MessageDigest.getInstance("SHA-1");
-			}
-			catch (NoSuchAlgorithmException ex) {
-				throw new IllegalStateException(ex);
-			}
-		}
-
 		private void load(InputStream inputStream) throws IOException {
 			byte[] buffer = new byte[BUFFER_SIZE];
 			int bytesRead;
 			while ((bytesRead = inputStream.read(buffer)) != -1) {
 				this.crc.update(buffer, 0, bytesRead);
-				if (this.messageDigest != null) {
-					this.messageDigest.update(buffer, 0, bytesRead);
-				}
 				this.size += bytesRead;
 			}
 		}
@@ -629,8 +613,8 @@ class BootZipCopyAction implements CopyAction {
 			entry.setCompressedSize(this.size);
 			entry.setCrc(this.crc.getValue());
 			entry.setMethod(ZipEntry.STORED);
-			if (this.messageDigest != null) {
-				entry.setComment("UNPACK:" + HexFormat.of().formatHex(this.messageDigest.digest()));
+			if (this.unpack) {
+				entry.setComment("UNPACK");
 			}
 		}
 

build-plugin/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/LoaderZipEntries.java

@@ -29,7 +29,6 @@ import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;
 import org.gradle.api.file.FileTreeElement;
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.util.Assert;
 import org.springframework.util.StreamUtils;
 
@@ -42,27 +41,22 @@ import org.springframework.util.StreamUtils;
  */
 class LoaderZipEntries {
 
-	private final LoaderImplementation loaderImplementation;
-
 	private final @Nullable Long entryTime;
 
 	private final int dirMode;
 
 	private final int fileMode;
 
-	LoaderZipEntries(@Nullable Long entryTime, int dirMode, int fileMode,
-			@Nullable LoaderImplementation loaderImplementation) {
+	LoaderZipEntries(@Nullable Long entryTime, int dirMode, int fileMode) {
 		this.entryTime = entryTime;
 		this.dirMode = dirMode;
 		this.fileMode = fileMode;
-		this.loaderImplementation = (loaderImplementation != null) ? loaderImplementation
-				: LoaderImplementation.DEFAULT;
 	}
 
 	WrittenEntries writeTo(ZipArchiveOutputStream out) throws IOException {
 		WrittenEntries written = new WrittenEntries();
 		try (ZipInputStream loaderJar = new ZipInputStream(
-				getResourceAsStream("/" + this.loaderImplementation.getJarResourceName()))) {
+				getResourceAsStream("/META-INF/loader/spring-boot-loader.jar"))) {
 			java.util.zip.ZipEntry entry = loaderJar.getNextEntry();
 			while (entry != null) {
 				if (entry.isDirectory() && !entry.getName().equals("META-INF/")) {

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/docs/PackagingDocumentationTests.java

@@ -124,7 +124,7 @@ class PackagingDocumentationTests {
 		try (JarFile jar = new JarFile(file)) {
 			JarEntry entry = jar.getJarEntry("BOOT-INF/lib/jruby-complete-1.7.25.jar");
 			assertThat(entry).isNotNull();
-			assertThat(entry.getComment()).startsWith("UNPACK:");
+			assertThat(entry.getComment()).isEqualTo("UNPACK");
 		}
 	}
 

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/buildinfo/BuildInfoTests.java

@@ -24,8 +24,6 @@ import java.time.format.DateTimeFormatter;
 import java.util.Properties;
 
 import org.gradle.api.Project;
-import org.gradle.api.internal.project.ProjectInternal;
-import org.gradle.initialization.GradlePropertiesController;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -173,11 +171,7 @@ class BuildInfoTests {
 
 	private Project createProject(String projectName) {
 		File projectDir = new File(this.temp, projectName);
-		Project project = GradleProjectBuilder.builder().withProjectDir(projectDir).withName(projectName).build();
-		((ProjectInternal) project).getServices()
-			.get(GradlePropertiesController.class)
-			.loadGradlePropertiesFrom(projectDir, false);
-		return project;
+		return GradleProjectBuilder.builder().withProjectDir(projectDir).withName(projectName).build();
 	}
 
 	private BuildInfo createTask(Project project) {

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/AbstractBootArchiveIntegrationTests.java

@@ -108,16 +108,6 @@ abstract class AbstractBootArchiveIntegrationTests {
 		assertThat(firstHash).isEqualTo(secondHash);
 	}
 
-	@TestTemplate
-	void classicLoader() throws IOException {
-		assertThat(this.gradleBuild.build(this.taskName).task(":" + this.taskName).getOutcome())
-			.isEqualTo(TaskOutcome.SUCCESS);
-		File jar = new File(this.gradleBuild.getProjectDir(), "build/libs").listFiles()[0];
-		try (JarFile jarFile = new JarFile(jar)) {
-			assertThat(jarFile.getEntry("org/springframework/boot/loader/LaunchedURLClassLoader.class")).isNotNull();
-		}
-	}
-
 	@TestTemplate
 	void upToDateWhenBuiltTwice() {
 		assertThat(this.gradleBuild.build(this.taskName).task(":" + this.taskName).getOutcome())
@@ -243,14 +233,8 @@ abstract class AbstractBootArchiveIntegrationTests {
 				.filter((entry) -> !entry.isDirectory())
 				.map(JarEntry::getName)
 				.filter((name) -> name.startsWith(this.libPath));
-			if (this.gradleBuild.gradleVersionIsLessThan("9.0.0-rc-1")) {
-				assertThat(libEntryNames).containsExactly(this.libPath + "two-1.0.jar",
-						this.libPath + "commons-io-2.19.0.jar");
-			}
-			else {
-				assertThat(libEntryNames).containsExactly(this.libPath + "commons-io-2.19.0.jar",
-						this.libPath + "two-1.0.jar");
-			}
+			assertThat(libEntryNames).containsExactly(this.libPath + "two-1.0.jar",
+					this.libPath + "commons-io-2.19.0.jar");
 		}
 	}
 
@@ -293,6 +277,7 @@ abstract class AbstractBootArchiveIntegrationTests {
 	void jarTypeFilteringIsApplied() throws IOException {
 		File flatDirRepository = new File(this.gradleBuild.getProjectDir(), "repository");
 		createDependenciesStarterJar(new File(flatDirRepository, "starter.jar"));
+		createDependenciesDeveloperToolsJar(new File(flatDirRepository, "devonly.jar"));
 		createStandardJar(new File(flatDirRepository, "standard.jar"));
 		assertThat(this.gradleBuild.build(this.taskName).task(":" + this.taskName).getOutcome())
 			.isEqualTo(TaskOutcome.SUCCESS);
@@ -669,6 +654,10 @@ abstract class AbstractBootArchiveIntegrationTests {
 		createJar(location, (attributes) -> attributes.putValue("Spring-Boot-Jar-Type", "dependencies-starter"));
 	}
 
+	private void createDependenciesDeveloperToolsJar(File location) throws IOException {
+		createJar(location, (attributes) -> attributes.putValue("Spring-Boot-Jar-Type", "development-tool"));
+	}
+
 	private void createJar(File location, Consumer<Attributes> attributesConfigurer) throws IOException {
 		location.getParentFile().mkdirs();
 		Manifest manifest = new Manifest();

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/AbstractBootArchiveTests.java

@@ -27,6 +27,8 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.nio.file.attribute.PosixFilePermission;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.HashMap;
@@ -35,6 +37,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.UUID;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.jar.JarOutputStream;
@@ -65,7 +68,6 @@ import org.junit.jupiter.api.io.TempDir;
 import org.springframework.boot.gradle.junit.GradleProjectBuilder;
 import org.springframework.boot.loader.tools.DefaultLaunchScript;
 import org.springframework.boot.loader.tools.JarModeLibrary;
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -283,17 +285,6 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 		}
 	}
 
-	@Test
-	void loaderIsWrittenToTheRootOfTheJarWhenUsingClassicLoader() throws IOException {
-		this.task.getMainClass().set("com.example.Main");
-		this.task.getLoaderImplementation().set(LoaderImplementation.CLASSIC);
-		executeTask();
-		try (JarFile jarFile = new JarFile(this.task.getArchiveFile().get().getAsFile())) {
-			assertThat(jarFile.getEntry("org/springframework/boot/loader/LaunchedURLClassLoader.class")).isNotNull();
-			assertThat(jarFile.getEntry("org/springframework/boot/loader/")).isNotNull();
-		}
-	}
-
 	@Test
 	void unpackCommentIsAddedToEntryIdentifiedByAPattern() throws IOException {
 		this.task.getMainClass().set("com.example.Main");
@@ -301,7 +292,7 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 		this.task.requiresUnpack("**/one.jar");
 		executeTask();
 		try (JarFile jarFile = new JarFile(this.task.getArchiveFile().get().getAsFile())) {
-			assertThat(jarFile.getEntry(this.libPath + "one.jar").getComment()).startsWith("UNPACK:");
+			assertThat(jarFile.getEntry(this.libPath + "one.jar").getComment()).isEqualTo("UNPACK");
 			assertThat(jarFile.getEntry(this.libPath + "two.jar").getComment()).isNull();
 		}
 	}
@@ -313,7 +304,7 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 		this.task.requiresUnpack((element) -> element.getName().endsWith("two.jar"));
 		executeTask();
 		try (JarFile jarFile = new JarFile(this.task.getArchiveFile().get().getAsFile())) {
-			assertThat(jarFile.getEntry(this.libPath + "two.jar").getComment()).startsWith("UNPACK:");
+			assertThat(jarFile.getEntry(this.libPath + "two.jar").getComment()).isEqualTo("UNPACK");
 			assertThat(jarFile.getEntry(this.libPath + "one.jar").getComment()).isNull();
 		}
 	}
@@ -419,23 +410,46 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 	}
 
 	@Test
-	void reproducibleOrderingCanBeEnabled() throws IOException {
+	void archiveIsReproducibleByDefault() throws IOException {
 		this.task.getMainClass().set("com.example.Main");
-		this.task.from(newFile("bravo.txt"), newFile("alpha.txt"), newFile("charlie.txt"));
-		this.task.setReproducibleFileOrder(true);
+		this.task.from(newFiles("files/b/bravo.txt", "files/a/alpha.txt", "files/c/charlie.txt"));
 		executeTask();
 		assertThat(this.task.getArchiveFile().get().getAsFile()).exists();
-		List<String> textFiles = new ArrayList<>();
+		List<String> files = new ArrayList<>();
 		try (JarFile jarFile = new JarFile(this.task.getArchiveFile().get().getAsFile())) {
 			Enumeration<JarEntry> entries = jarFile.entries();
 			while (entries.hasMoreElements()) {
 				JarEntry entry = entries.nextElement();
-				if (entry.getName().endsWith(".txt")) {
-					textFiles.add(entry.getName());
+				OffsetDateTime lastModifiedTime = entry.getLastModifiedTime().toInstant().atOffset(ZoneOffset.UTC);
+				assertThat(lastModifiedTime).isEqualTo(OffsetDateTime.of(1980, 2, 1, 0, 0, 0, 0, ZoneOffset.UTC));
+				if (entry.getName().startsWith("files/")) {
+					files.add(entry.getName());
+				}
+			}
+		}
+		assertThat(files).containsExactly("files/", "files/a/", "files/a/alpha.txt", "files/b/", "files/b/bravo.txt",
+				"files/c/", "files/c/charlie.txt");
+	}
+
+	@Test
+	void archiveReproducibilityCanBeDisabled() throws IOException {
+		this.task.getMainClass().set("com.example.Main");
+		this.task.from(newFiles("files/b/bravo.txt", "files/a/alpha.txt", "files/c/charlie.txt"));
+		this.task.setPreserveFileTimestamps(true);
+		this.task.setReproducibleFileOrder(false);
+		executeTask();
+		assertThat(this.task.getArchiveFile().get().getAsFile()).exists();
+		try (JarFile jarFile = new JarFile(this.task.getArchiveFile().get().getAsFile())) {
+			Enumeration<JarEntry> entries = jarFile.entries();
+			while (entries.hasMoreElements()) {
+				JarEntry entry = entries.nextElement();
+				if (entry.getName().endsWith(".txt") || entry.getName().startsWith("BOOT-INF/lib/")) {
+					OffsetDateTime lastModifiedTime = entry.getLastModifiedTime().toInstant().atOffset(ZoneOffset.UTC);
+					assertThat(lastModifiedTime)
+						.isNotEqualTo(OffsetDateTime.of(1980, 2, 1, 0, 0, 0, 0, ZoneOffset.UTC));
 				}
 			}
 		}
-		assertThat(textFiles).containsExactly("alpha.txt", "bravo.txt", "charlie.txt");
 	}
 
 	@Test
@@ -675,6 +689,19 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 		return entryNames;
 	}
 
+	protected File newFiles(String... names) throws IOException {
+		File dir = new File(this.temp, UUID.randomUUID().toString());
+		dir.mkdir();
+		List<File> files = new ArrayList<>();
+		for (String name : names) {
+			File file = new File(dir, name);
+			file.getParentFile().mkdirs();
+			file.createNewFile();
+			files.add(file);
+		}
+		return dir;
+	}
+
 	protected File newFile(String name) throws IOException {
 		File file = new File(this.temp, name);
 		file.createNewFile();

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImageTests.java

@@ -30,8 +30,8 @@ import org.junit.jupiter.api.io.TempDir;
 import org.springframework.boot.buildpack.platform.build.BuildRequest;
 import org.springframework.boot.buildpack.platform.build.BuildpackReference;
 import org.springframework.boot.buildpack.platform.build.PullPolicy;
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.gradle.junit.GradleProjectBuilder;
 

build-plugin/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests.java

@@ -66,18 +66,10 @@ class BootJarIntegrationTests extends AbstractBootArchiveIntegrationTests {
 		copyClasspathApplication();
 		BuildResult result = this.gradleBuild.build("launch");
 		String output = result.getOutput();
-		if (this.gradleBuild.gradleVersionIsLessThan("9.0.0-rc-1")) {
-			assertThat(output).containsPattern("1\\. .*classes");
-			assertThat(output).containsPattern("2\\. .*library-1.0-SNAPSHOT.jar");
-			assertThat(output).containsPattern("3\\. .*commons-lang3-3.9.jar");
-			assertThat(output).containsPattern("4\\. .*spring-boot-jarmode-tools.*.jar");
-		}
-		else {
-			assertThat(output).containsPattern("1\\. .*classes");
-			assertThat(output).containsPattern("2\\. .*commons-lang3-3.9.jar");
-			assertThat(output).containsPattern("3\\. .*library-1.0-SNAPSHOT.jar");
-			assertThat(output).containsPattern("4\\. .*spring-boot-jarmode-tools.*.jar");
-		}
+		assertThat(output).containsPattern("1\\. .*classes");
+		assertThat(output).containsPattern("2\\. .*library-1.0-SNAPSHOT.jar");
+		assertThat(output).containsPattern("3\\. .*commons-lang3-3.9.jar");
+		assertThat(output).containsPattern("4\\. .*spring-boot-jarmode-tools.*.jar");
 		assertThat(output).doesNotContain("5. ");
 	}
 
@@ -86,18 +78,10 @@ class BootJarIntegrationTests extends AbstractBootArchiveIntegrationTests {
 		copyClasspathApplication();
 		BuildResult result = this.gradleBuild.build("launch");
 		String output = result.getOutput();
-		if (this.gradleBuild.gradleVersionIsLessThan("9.0.0-rc-1")) {
-			assertThat(output).containsPattern("1\\. .*classes");
-			assertThat(output).containsPattern("2\\. .*spring-boot-jarmode-tools.*.jar");
-			assertThat(output).containsPattern("3\\. .*library-1.0-SNAPSHOT.jar");
-			assertThat(output).containsPattern("4\\. .*commons-lang3-3.9.jar");
-		}
-		else {
-			assertThat(output).containsPattern("1\\. .*classes");
-			assertThat(output).containsPattern("2\\. .*spring-boot-jarmode-tools.*.jar");
-			assertThat(output).containsPattern("3\\. .*commons-lang3-3.9.jar");
-			assertThat(output).containsPattern("4\\. .*library-1.0-SNAPSHOT.jar");
-		}
+		assertThat(output).containsPattern("1\\. .*classes");
+		assertThat(output).containsPattern("2\\. .*spring-boot-jarmode-tools.*.jar");
+		assertThat(output).containsPattern("3\\. .*library-1.0-SNAPSHOT.jar");
+		assertThat(output).containsPattern("4\\. .*commons-lang3-3.9.jar");
 		assertThat(output).doesNotContain("5. ");
 	}
 

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/dsl/BuildInfoDslIntegrationTests-jarWithCustomName.gradle

@@ -29,7 +29,7 @@ bootJar {
 		baseName = 'foo'
 	}
 	else {
-		archiveBaseName = 'foo'	
+		archiveBaseName = 'foo'
 	}
 }
 

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/dsl/BuildInfoDslIntegrationTests-warWithCustomName.gradle

@@ -29,7 +29,7 @@ bootWar {
 		baseName = 'foo'
 	}
 	else {
-		archiveBaseName = 'foo'	
+		archiveBaseName = 'foo'
 	}
 }
 

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/SpringBootAotPluginIntegrationTests-processTestAotHasLibraryResourcesOnItsClasspath.gradle

@@ -42,7 +42,7 @@ dependencies {
 }
 
 task('processTestAotClasspath') {
-	dependsOn configurations.processTestAotClasspath 
+	dependsOn configurations.processTestAotClasspath
 	doFirst {
 		configurations.processTestAotClasspath.files.each { println it }
 	}

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/plugin/SpringBootAotPluginIntegrationTests-processTestAotHasTransitiveRuntimeDependenciesOnItsClasspath.gradle

@@ -42,7 +42,7 @@ dependencies {
 }
 
 task('processTestAotClasspath') {
-	dependsOn configurations.processTestAotClasspath 
+	dependsOn configurations.processTestAotClasspath
 	doFirst {
 		configurations.processTestAotClasspath.files.each { println it }
 	}

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-customLayers.gradle

@@ -33,7 +33,7 @@ bootJar {
 				include "*:*:*SNAPSHOT"
 			}
 			intoLayer("commons-dependencies") {
-				include "org.apache.commons:*" 
+				include "org.apache.commons:*"
 			}
 			intoLayer("dependencies")
 		}

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-multiModuleCustomLayers.gradle

@@ -48,7 +48,7 @@ bootJar {
 				includeProjectDependencies()
 			}
 			intoLayer("commons-dependencies") {
-				include "org.apache.commons:*" 
+				include "org.apache.commons:*"
 			}
 			intoLayer("dependencies")
 		}

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-reproducibleArchive.gradle

@@ -21,6 +21,8 @@ plugins {
 
 bootJar {
 	mainClass = 'com.example.Application'
-	preserveFileTimestamps = false
-	reproducibleFileOrder = true
+	if (GradleVersion.current().compareTo(GradleVersion.version("9.0.0-rc-1")) < 0) {
+		preserveFileTimestamps = false
+		reproducibleFileOrder = true
+	}
 }

build-plugin/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-reproducibleArchive.gradle

@@ -21,6 +21,8 @@ plugins {
 
 bootWar {
 	mainClass = 'com.example.Application'
-	preserveFileTimestamps = false
-	reproducibleFileOrder = true
+	if (GradleVersion.current().compareTo(GradleVersion.version("9.0.0-rc-1")) < 0) {
+		preserveFileTimestamps = false
+		reproducibleFileOrder = true
+	}
 }

build-plugin/spring-boot-maven-plugin/src/docs/antora/modules/maven-plugin/examples/using/different-versions-pom.xml

@@ -6,7 +6,7 @@
 	<!-- tag::different-versions[] -->
 	<properties>
 		<slf4j.version>1.7.30</slf4j.version>
-		<spring-data-releasetrain.version>Moore-SR6</spring-data-releasetrain.version>
+		<spring-data-bom.version>2024.1.10</spring-data-bom.version>
 	</properties>
 	<!-- end::different-versions[] -->
 

build-plugin/spring-boot-maven-plugin/src/docs/antora/modules/maven-plugin/examples/using/no-starter-parent-override-dependencies-pom.xml

@@ -24,8 +24,8 @@
 			<!-- Override Spring Data release train provided by Spring Boot -->
 			<dependency>
 				<groupId>org.springframework.data</groupId>
-				<artifactId>spring-data-releasetrain</artifactId>
-				<version>2020.0.0-SR1</version>
+				<artifactId>spring-data-bom</artifactId>
+				<version>2024.1.10</version>
 				<type>pom</type>
 				<scope>import</scope>
 			</dependency>

build-plugin/spring-boot-maven-plugin/src/docs/antora/modules/maven-plugin/pages/using.adoc

@@ -67,6 +67,9 @@ include::example$using/different-versions-pom.xml[tags=different-versions]
 
 Browse the xref:appendix:dependency-versions/properties.adoc[Dependency Versions Properties] section in the Spring Boot reference for a complete list of dependency version properties.
 
+WARNING: Each Spring Boot release is designed and tested against a specific set of third-party dependencies.
+Overriding versions may cause compatibility issues and should be done with care.
+
 
 
 [[using.import]]

build-plugin/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/AbstractArchiveIntegrationTests.java

@@ -159,7 +159,7 @@ abstract class AbstractArchiveIntegrationTests {
 					Optional<JarEntry> match = entries.filter((entry) -> entry.getName().startsWith(prefix))
 						.findFirst();
 					assertThat(match).as("Name starting with %s", prefix)
-						.hasValueSatisfying((entry) -> assertThat(entry.getComment()).startsWith("UNPACK:"));
+						.hasValueSatisfying((entry) -> assertThat(entry.getComment()).isEqualTo("UNPACK"));
 				});
 			});
 			return this;

build-plugin/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/JarIntegrationTests.java

@@ -76,26 +76,6 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 		});
 	}
 
-	@TestTemplate
-	void whenJarWithClassicLoaderIsRepackagedInPlaceOnlyRepackagedJarIsInstalled(MavenBuild mavenBuild) {
-		mavenBuild.project("jar-with-classic-loader").goals("install").execute((project) -> {
-			File original = new File(project, "target/jar-with-classic-loader-0.0.1.BUILD-SNAPSHOT.jar.original");
-			assertThat(original).isFile();
-			File repackaged = new File(project, "target/jar-with-classic-loader-0.0.1.BUILD-SNAPSHOT.jar");
-			assertThat(launchScript(repackaged)).isEmpty();
-			assertThat(jar(repackaged)).manifest((manifest) -> {
-				manifest.hasMainClass("org.springframework.boot.loader.launch.JarLauncher");
-				manifest.hasStartClass("some.random.Main");
-				manifest.hasAttribute("Not-Used", "Foo");
-			}).hasEntryWithName("org/springframework/boot/loader/launch/JarLauncher.class");
-			assertThat(buildLog(project))
-				.contains("Replacing main artifact " + repackaged + " with repackaged archive,")
-				.contains("The original artifact has been renamed to " + original)
-				.contains("Installing " + repackaged + " to")
-				.doesNotContain("Installing " + original + " to");
-		});
-	}
-
 	@TestTemplate
 	void whenAttachIsDisabledOnlyTheOriginalJarIsInstalled(MavenBuild mavenBuild) {
 		mavenBuild.project("jar-attach-disabled").goals("install").execute((project) -> {
@@ -196,7 +176,40 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
 				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
 				.hasEntryWithNameStartingWith("BOOT-INF/lib/commons-logging")
-				.doesNotHaveEntryWithName("BOOT-INF/lib/servlet-api-2.5.jar");
+				.doesNotHaveEntryWithNameStartingWith("BOOT-INF/lib/servlet-api-");
+		});
+	}
+
+	@TestTemplate
+	void whenAnEntryIsOptionalByDefaultDoesNotAppearInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-default").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-default-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.doesNotHaveEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
+		});
+	}
+
+	@TestTemplate
+	void whenAnEntryIsOptionalAndOptionalsIncludedAppearsInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-include").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-include-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
+		});
+	}
+
+	@TestTemplate
+	void whenAnEntryIsOptionalAndOptionalsExcludedDoesNotAppearInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-exclude").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-exclude-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.doesNotHaveEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
 		});
 	}
 
@@ -248,9 +261,8 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 			File repackaged = new File(project, "target/jar-exclude-group-0.0.1.BUILD-SNAPSHOT.jar");
 			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
 				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
-				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
 				.hasEntryWithNameStartingWith("BOOT-INF/lib/commons-logging")
-				.doesNotHaveEntryWithName("BOOT-INF/lib/log4j-api-2.4.1.jar");
+				.doesNotHaveEntryWithName("BOOT-INF/lib/log4j-api-");
 		});
 	}
 
@@ -388,7 +400,7 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 				assertThat(layerIndex.get("application")).contains("BOOT-INF/lib/jar-release-0.0.1.RELEASE.jar",
 						"BOOT-INF/lib/jar-snapshot-0.0.1.BUILD-SNAPSHOT.jar");
 				assertThat(layerIndex.get("dependencies"))
-					.anyMatch((dependency) -> dependency.startsWith("BOOT-INF/lib/log4j-api-2"));
+					.anyMatch((dependency) -> dependency.startsWith("BOOT-INF/lib/log4j-api-"));
 			}
 			catch (IOException ex) {
 				// Ignore

build-plugin/spring-boot-maven-plugin/src/intTest/projects/jar-optional-default/pom.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-optional-default</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/jar-optional-exclude/pom.xml

@@ -3,7 +3,7 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.springframework.boot.maven.it</groupId>
-	<artifactId>jar-with-classic-loader</artifactId>
+	<artifactId>jar-optional-exclude</artifactId>
 	<version>0.0.1.BUILD-SNAPSHOT</version>
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -22,7 +22,7 @@
 							<goal>repackage</goal>
 						</goals>
 						<configuration>
-							<loaderImplementation>CLASSIC</loaderImplementation>
+							<includeOptional>false</includeOptional>
 						</configuration>
 					</execution>
 				</executions>
@@ -31,16 +31,6 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-jar-plugin</artifactId>
 				<version>@maven-jar-plugin.version@</version>
-				<configuration>
-					<archive>
-						<manifest>
-							<mainClass>some.random.Main</mainClass>
-						</manifest>
-						<manifestEntries>
-							<Not-Used>Foo</Not-Used>
-						</manifestEntries>
-					</archive>
-				</configuration>
 			</plugin>
 		</plugins>
 	</build>
@@ -51,10 +41,10 @@
 			<version>@spring-framework.version@</version>
 		</dependency>
 		<dependency>
-			<groupId>jakarta.servlet</groupId>
-			<artifactId>jakarta.servlet-api</artifactId>
-			<version>@jakarta-servlet.version@</version>
-			<scope>provided</scope>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
 		</dependency>
 	</dependencies>
 </project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/jar-optional-exclude/src/main/java/org/test/SampleApplication.java

@@ -14,7 +14,11 @@
  * limitations under the License.
  */
 
-/**
- * Utilities used by Spring Boot's JAR loading.
- */
-package org.springframework.boot.loader.util;
+package org.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/jar-optional-include/pom.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-optional-include</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<includeOptional>true</includeOptional>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/jar-optional-include/src/main/java/org/test/SampleApplication.java

@@ -14,7 +14,11 @@
  * limitations under the License.
  */
 
-/**
- * Support for loading and manipulating JAR/WAR files.
- */
-package org.springframework.boot.loader.jar;
+package org.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AbstractPackagerMojo.java

@@ -47,7 +47,6 @@ import org.springframework.boot.loader.tools.Layouts.Jar;
 import org.springframework.boot.loader.tools.Layouts.None;
 import org.springframework.boot.loader.tools.Layouts.War;
 import org.springframework.boot.loader.tools.Libraries;
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.boot.loader.tools.Packager;
 import org.springframework.boot.loader.tools.layer.CustomLayers;
 
@@ -114,6 +113,13 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	@Parameter(defaultValue = "false")
 	public boolean includeSystemScope;
 
+	/**
+	 * Include optional dependencies.
+	 * @since 3.5.7
+	 */
+	@Parameter(defaultValue = "false")
+	public boolean includeOptional;
+
 	/**
 	 * Include JAR tools.
 	 * @since 3.3.0
@@ -142,15 +148,6 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 		return null;
 	}
 
-	/**
-	 * Return the loader implementation that should be used.
-	 * @return the loader implementation or {@code null}
-	 * @since 3.2.0
-	 */
-	protected @Nullable LoaderImplementation getLoaderImplementation() {
-		return null;
-	}
-
 	/**
 	 * Return the layout factory that will be used to determine the {@link LayoutType} if
 	 * no explicit layout is set.
@@ -168,7 +165,6 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	 */
 	protected <P extends Packager> P getConfiguredPackager(Supplier<P> supplier) {
 		P packager = supplier.get();
-		packager.setLoaderImplementation(getLoaderImplementation());
 		packager.setLayoutFactory(getLayoutFactory());
 		packager.addMainClassTimeoutWarningListener(new LoggingMainClassTimeoutWarningListener(this::getLog));
 		packager.setMainClass(this.mainClass);
@@ -231,6 +227,9 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 		if (!this.includeSystemScope) {
 			filters.add(new ScopeFilter(null, Artifact.SCOPE_SYSTEM));
 		}
+		if (!this.includeOptional) {
+			filters.add(DependencyFilter.exclude(Artifact::isOptional));
+		}
 		return filters.toArray(new ArtifactsFilter[0]);
 	}
 

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/BuildImageMojo.java

@@ -50,7 +50,6 @@ import org.springframework.boot.loader.tools.EntryWriter;
 import org.springframework.boot.loader.tools.ImagePackager;
 import org.springframework.boot.loader.tools.LayoutFactory;
 import org.springframework.boot.loader.tools.Libraries;
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -208,13 +207,6 @@ public abstract class BuildImageMojo extends AbstractPackagerMojo {
 	@Parameter
 	private @Nullable LayoutType layout;
 
-	/**
-	 * The loader implementation that should be used.
-	 * @since 3.2.0
-	 */
-	@Parameter
-	private @Nullable LoaderImplementation loaderImplementation;
-
 	/**
 	 * The layout factory that will be used to create the executable archive if no
 	 * explicit layout is set. Alternative layouts implementations can be provided by 3rd
@@ -238,11 +230,6 @@ public abstract class BuildImageMojo extends AbstractPackagerMojo {
 		return this.layout;
 	}
 
-	@Override
-	protected @Nullable LoaderImplementation getLoaderImplementation() {
-		return this.loaderImplementation;
-	}
-
 	/**
 	 * Return the layout factory that will be used to determine the
 	 * {@link AbstractPackagerMojo.LayoutType} if no explicit layout is set.

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/DependencyFilter.java

@@ -16,9 +16,11 @@
 
 package org.springframework.boot.maven;
 
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Predicate;
 
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.shared.artifact.filter.collection.AbstractArtifactsFilter;
@@ -81,4 +83,22 @@ public abstract class DependencyFilter extends AbstractArtifactsFilter {
 		return this.filters;
 	}
 
+	/**
+	 * Return a new {@link DependencyFilter} the excludes artifacts based on the given
+	 * predicate.
+	 * @param filter the predicate used to filter the artifacts.
+	 * @return a new {@link DependencyFilter} instance
+	 * @since 3.5.7
+	 */
+	public static DependencyFilter exclude(Predicate<Artifact> filter) {
+		return new DependencyFilter(Collections.emptyList()) {
+
+			@Override
+			protected boolean filter(Artifact artifact) {
+				return filter.test(artifact);
+			}
+
+		};
+	}
+
 }

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/JarTypeFilter.java

@@ -34,8 +34,8 @@ import org.apache.maven.artifact.Artifact;
  */
 class JarTypeFilter extends DependencyFilter {
 
-	private static final Set<String> EXCLUDED_JAR_TYPES = Collections
-		.unmodifiableSet(new HashSet<>(Arrays.asList("annotation-processor", "dependencies-starter")));
+	private static final Set<String> EXCLUDED_JAR_TYPES = Collections.unmodifiableSet(
+			new HashSet<>(Arrays.asList("annotation-processor", "dependencies-starter", "development-tool")));
 
 	JarTypeFilter() {
 		super(Collections.emptyList());

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RepackageMojo.java

@@ -40,7 +40,6 @@ import org.springframework.boot.loader.tools.DefaultLaunchScript;
 import org.springframework.boot.loader.tools.LaunchScript;
 import org.springframework.boot.loader.tools.LayoutFactory;
 import org.springframework.boot.loader.tools.Libraries;
-import org.springframework.boot.loader.tools.LoaderImplementation;
 import org.springframework.boot.loader.tools.Repackager;
 import org.springframework.lang.Contract;
 import org.springframework.util.StringUtils;
@@ -170,13 +169,6 @@ public class RepackageMojo extends AbstractPackagerMojo {
 	@Parameter(property = "spring-boot.repackage.layout")
 	private @Nullable LayoutType layout;
 
-	/**
-	 * The loader implementation that should be used.
-	 * @since 3.2.0
-	 */
-	@Parameter
-	private @Nullable LoaderImplementation loaderImplementation;
-
 	/**
 	 * The layout factory that will be used to create the executable archive if no
 	 * explicit layout is set. Alternative layouts implementations can be provided by 3rd
@@ -201,11 +193,6 @@ public class RepackageMojo extends AbstractPackagerMojo {
 		return this.layout;
 	}
 
-	@Override
-	protected @Nullable LoaderImplementation getLoaderImplementation() {
-		return this.loaderImplementation;
-	}
-
 	/**
 	 * Return the layout factory that will be used to determine the
 	 * {@link AbstractPackagerMojo.LayoutType} if no explicit layout is set.

build-plugin/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/DependencyFilterTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-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.boot.maven;
+
+import java.util.Set;
+
+import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.DefaultArtifact;
+import org.apache.maven.artifact.handler.ArtifactHandler;
+import org.apache.maven.artifact.handler.DefaultArtifactHandler;
+import org.apache.maven.artifact.versioning.VersionRange;
+import org.apache.maven.shared.artifact.filter.collection.ArtifactFilterException;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link DependencyFilter}.
+ *
+ * @author Phillip Webb
+ */
+class DependencyFilterTests {
+
+	@Test
+	void excludeFiltersBasedOnPredicate() throws ArtifactFilterException {
+		DependencyFilter filter = DependencyFilter.exclude(Artifact::isOptional);
+		ArtifactHandler ah = new DefaultArtifactHandler();
+		VersionRange v = VersionRange.createFromVersion("1.0.0");
+		DefaultArtifact a1 = new DefaultArtifact("com.example", "a1", v, "compile", "jar", null, ah, false);
+		DefaultArtifact a2 = new DefaultArtifact("com.example", "a2", v, "compile", "jar", null, ah, true);
+		DefaultArtifact a3 = new DefaultArtifact("com.example", "a3", v, "compile", "jar", null, ah, false);
+		Set<Artifact> filtered = filter.filter(Set.of(a1, a2, a3));
+		assertThat(filtered).containsExactlyInAnyOrder(a1, a3);
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/ImageTests.java

@@ -31,8 +31,8 @@ import org.springframework.boot.buildpack.platform.build.BuildRequest;
 import org.springframework.boot.buildpack.platform.build.BuildpackReference;
 import org.springframework.boot.buildpack.platform.build.Cache;
 import org.springframework.boot.buildpack.platform.build.PullPolicy;
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;

build-plugin/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/JarTypeFilterTests.java

@@ -60,6 +60,11 @@ class JarTypeFilterTests {
 		assertThat(new JarTypeFilter().filter(createArtifact("annotation-processor"))).isTrue();
 	}
 
+	@Test
+	void whenArtifactHasDevelopmentToolJarTypeThenItIsExcluded() {
+		assertThat(new JarTypeFilter().filter(createArtifact("development-tool"))).isTrue();
+	}
+
 	@Test
 	void whenArtifactHasNoManifestFileThenItIsIncluded() {
 		assertThat(new JarTypeFilter().filter(createArtifactWithNoManifest())).isFalse();

buildSrc/build.gradle

@@ -52,7 +52,7 @@ dependencies {
 	implementation("commons-codec:commons-codec:${commonsCodecVersion}")
 	implementation("de.undercouch.download:de.undercouch.download.gradle.plugin:5.5.0")
 	implementation("dev.adamko.dokkatoo:dokkatoo-plugin:2.3.1")
-	implementation("io.gitlab.arturbosch.detekt:detekt-gradle-plugin:1.23.8")
+	implementation("dev.detekt:detekt-gradle-plugin:2.0.0-alpha.0")
 	implementation("io.spring.gradle.antora:spring-antora-plugin:0.0.1")
 	implementation("io.spring.javaformat:spring-javaformat-gradle-plugin:${javaFormatVersion}")
 	implementation("io.spring.nohttp:nohttp-gradle:0.0.11")
@@ -133,10 +133,6 @@ gradlePlugin {
 			id = "org.springframework.boot.integration-test"
 			implementationClass = "org.springframework.boot.build.test.IntegrationTestPlugin"
 		}
-		systemTestPlugin {
-			id = "org.springframework.boot.system-test"
-			implementationClass = "org.springframework.boot.build.test.SystemTestPlugin"
-		}
 		mavenPluginPlugin {
 			id = "org.springframework.boot.maven-plugin"
 			implementationClass = "org.springframework.boot.build.mavenplugin.MavenPluginPlugin"
@@ -153,10 +149,22 @@ gradlePlugin {
 			id = "org.springframework.boot.starter"
 			implementationClass = "org.springframework.boot.build.starters.StarterPlugin"
 		}
+		systemTestPlugin {
+			id = "org.springframework.boot.system-test"
+			implementationClass = "org.springframework.boot.build.test.SystemTestPlugin"
+		}
+		testAutoConfigurationPlugin {
+			id = "org.springframework.boot.test-auto-configuration"
+			implementationClass = "org.springframework.boot.build.test.autoconfigure.TestAutoConfigurationPlugin"
+		}
 		testFailuresPlugin {
 			id = "org.springframework.boot.test-failures"
 			implementationClass = "org.springframework.boot.build.testing.TestFailuresPlugin"
 		}
+		testSlicePlugin {
+			id = "org.springframework.boot.test-slice"
+			implementationClass = "org.springframework.boot.build.test.autoconfigure.TestSlicePlugin"
+		}
 	}
 }
 

buildSrc/src/main/java/org/springframework/boot/build/KotlinConventions.java

@@ -20,9 +20,9 @@ import java.net.URI;
 
 import dev.adamko.dokkatoo.DokkatooExtension;
 import dev.adamko.dokkatoo.formats.DokkatooHtmlPlugin;
-import io.gitlab.arturbosch.detekt.Detekt;
-import io.gitlab.arturbosch.detekt.DetektPlugin;
-import io.gitlab.arturbosch.detekt.extensions.DetektExtension;
+import dev.detekt.gradle.Detekt;
+import dev.detekt.gradle.extensions.DetektExtension;
+import dev.detekt.gradle.plugin.DetektPlugin;
 import org.gradle.api.Project;
 import org.gradle.api.tasks.SourceSet;
 import org.gradle.api.tasks.SourceSetContainer;
@@ -76,6 +76,7 @@ class KotlinConventions {
 
 	private void configureDokkatoo(Project project) {
 		DokkatooExtension dokkatoo = project.getExtensions().getByType(DokkatooExtension.class);
+		dokkatoo.getVersions().getJetbrainsDokka().set("2.1.0-Beta");
 		dokkatoo.getDokkatooSourceSets().configureEach((sourceSet) -> {
 			if (SourceSet.MAIN_SOURCE_SET_NAME.equals(sourceSet.getName())) {
 				sourceSet.getSourceRoots().setFrom(project.file("src/main/kotlin"));
@@ -103,7 +104,9 @@ class KotlinConventions {
 		project.getPlugins().apply(DetektPlugin.class);
 		DetektExtension detekt = project.getExtensions().getByType(DetektExtension.class);
 		detekt.getConfig().setFrom(project.getRootProject().file("config/detekt/config.yml"));
-		project.getTasks().withType(Detekt.class).configureEach((task) -> task.setJvmTarget(JVM_TARGET.getTarget()));
+		project.getTasks()
+			.withType(Detekt.class)
+			.configureEach((task) -> task.getJvmTarget().set(JVM_TARGET.getTarget()));
 	}
 
 }

buildSrc/src/main/java/org/springframework/boot/build/architecture/ArchitectureRules.java

@@ -80,6 +80,8 @@ final class ArchitectureRules {
 
 	private static final String AUTOCONFIGURATION_ANNOTATION = "org.springframework.boot.autoconfigure.AutoConfiguration";
 
+	private static final String TEST_AUTOCONFIGURATION_ANNOTATION = "org.springframework.boot.test.autoconfigure.TestAutoConfiguration";
+
 	private ArchitectureRules() {
 	}
 
@@ -112,6 +114,7 @@ final class ArchitectureRules {
 		rules.add(allConfigurationPropertiesBindingBeanMethodsShouldBeStatic());
 		rules.add(autoConfigurationClassesShouldBePublicAndFinal());
 		rules.add(autoConfigurationClassesShouldHaveNoPublicMembers());
+		rules.add(testAutoConfigurationClassesShouldBePackagePrivateAndFinal());
 		return List.copyOf(rules);
 	}
 
@@ -130,7 +133,12 @@ final class ArchitectureRules {
 	}
 
 	private static ArchRule allPackagesShouldBeFreeOfTangles() {
-		return SlicesRuleDefinition.slices().matching("(**)").should().beFreeOfCycles();
+		return SlicesRuleDefinition.slices()
+			.matching("(**)")
+			.should()
+			.beFreeOfCycles()
+			.ignoreDependency("org.springframework.boot.env.EnvironmentPostProcessor",
+					"org.springframework.boot.SpringApplication");
 	}
 
 	private static ArchRule allBeanPostProcessorBeanMethodsShouldBeStaticAndNotCausePrematureInitialization() {
@@ -353,8 +361,7 @@ final class ArchitectureRules {
 
 	private static ArchRule autoConfigurationClassesShouldBePublicAndFinal() {
 		return ArchRuleDefinition.classes()
-			.that()
-			.areAnnotatedWith(AUTOCONFIGURATION_ANNOTATION)
+			.that(areRegularAutoConfiguration())
 			.should()
 			.bePublic()
 			.andShould()
@@ -365,8 +372,7 @@ final class ArchitectureRules {
 	private static ArchRule autoConfigurationClassesShouldHaveNoPublicMembers() {
 		return ArchRuleDefinition.members()
 			.that()
-			.areDeclaredInClassesThat()
-			.areAnnotatedWith(AUTOCONFIGURATION_ANNOTATION)
+			.areDeclaredInClassesThat(areRegularAutoConfiguration())
 			.and(areNotDefaultConstructors())
 			.and(areNotConstants())
 			.and(dontOverridePublicMethods())
@@ -375,6 +381,24 @@ final class ArchitectureRules {
 			.allowEmptyShould(true);
 	}
 
+	private static ArchRule testAutoConfigurationClassesShouldBePackagePrivateAndFinal() {
+		return ArchRuleDefinition.classes()
+			.that()
+			.areAnnotatedWith(TEST_AUTOCONFIGURATION_ANNOTATION)
+			.should()
+			.bePackagePrivate()
+			.andShould()
+			.haveModifier(JavaModifier.FINAL)
+			.allowEmptyShould(true);
+	}
+
+	private static DescribedPredicate<JavaClass> areRegularAutoConfiguration() {
+		return DescribedPredicate.describe("Regular @AutoConfiguration",
+				(javaClass) -> javaClass.isMetaAnnotatedWith(AUTOCONFIGURATION_ANNOTATION)
+						&& !javaClass.isMetaAnnotatedWith(TEST_AUTOCONFIGURATION_ANNOTATION)
+						&& !javaClass.isAnnotation());
+	}
+
 	private static DescribedPredicate<? super JavaMember> dontOverridePublicMethods() {
 		OverridesPublicMethod<JavaMember> predicate = new OverridesPublicMethod<>();
 		return DescribedPredicate.describe("don't override public methods", (member) -> !predicate.test(member));

buildSrc/src/main/java/org/springframework/boot/build/autoconfigure/AutoConfigurationClass.java

@@ -19,6 +19,7 @@ package org.springframework.boot.build.autoconfigure;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -54,8 +55,8 @@ public record AutoConfigurationClass(String name, List<String> before, List<Stri
 				attributes.getOrDefault("afterName", Collections.emptyList()));
 	}
 
-	static AutoConfigurationClass of(File classFile) {
-		try (FileInputStream input = new FileInputStream(classFile)) {
+	public static AutoConfigurationClass of(InputStream input) {
+		try {
 			ClassReader classReader = new ClassReader(input);
 			AutoConfigurationClassVisitor visitor = new AutoConfigurationClassVisitor();
 			classReader.accept(visitor, ClassReader.SKIP_DEBUG | ClassReader.SKIP_CODE | ClassReader.SKIP_FRAMES);
@@ -66,6 +67,15 @@ public record AutoConfigurationClass(String name, List<String> before, List<Stri
 		}
 	}
 
+	static AutoConfigurationClass of(File classFile) {
+		try (InputStream input = new FileInputStream(classFile)) {
+			return of(input);
+		}
+		catch (IOException ex) {
+			throw new UncheckedIOException(ex);
+		}
+	}
+
 	private static final class AutoConfigurationClassVisitor extends ClassVisitor {
 
 		private AutoConfigurationClass autoConfigurationClass;

buildSrc/src/main/java/org/springframework/boot/build/autoconfigure/AutoConfigurationImportsTask.java

@@ -38,7 +38,10 @@ import org.gradle.api.tasks.SkipWhenEmpty;
  */
 public abstract class AutoConfigurationImportsTask extends DefaultTask {
 
-	static final String IMPORTS_FILE = "META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports";
+	/**
+	 * The path of the {@code AutoConfiguration.imports} file.
+	 */
+	public static final String IMPORTS_FILE = "META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports";
 
 	private FileCollection sourceFiles = getProject().getObjects().fileCollection();
 

buildSrc/src/main/java/org/springframework/boot/build/context/properties/ConfigurationPropertiesPlugin.java

@@ -65,7 +65,7 @@ public class ConfigurationPropertiesPlugin implements Plugin<Project> {
 	public static final String CHECK_ADDITIONAL_SPRING_CONFIGURATION_METADATA_TASK_NAME = "checkAdditionalSpringConfigurationMetadata";
 
 	/**
-	 * Name of the {@link CheckAdditionalSpringConfigurationMetadata} task.
+	 * Name of the {@link CheckSpringConfigurationMetadata} task.
 	 */
 	public static final String CHECK_SPRING_CONFIGURATION_METADATA_TASK_NAME = "checkSpringConfigurationMetadata";
 

buildSrc/src/main/java/org/springframework/boot/build/optional/OptionalDependenciesPlugin.java

@@ -41,7 +41,7 @@ public class OptionalDependenciesPlugin implements Plugin<Project> {
 	@Override
 	public void apply(Project project) {
 		Configuration optional = project.getConfigurations().create("optional");
-		optional.setCanBeConsumed(false);
+		optional.setCanBeConsumed(true);
 		optional.setCanBeResolved(false);
 		project.getPlugins().withType(JavaPlugin.class, (javaPlugin) -> {
 			SourceSetContainer sourceSets = project.getExtensions()

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/CheckAutoConfigureImports.java

@@ -0,0 +1,233 @@
+/*
+ * Copyright 2025-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.boot.build.test.autoconfigure;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.function.Consumer;
+import java.util.jar.JarFile;
+import java.util.stream.Collectors;
+import java.util.zip.ZipEntry;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.file.DirectoryProperty;
+import org.gradle.api.file.FileCollection;
+import org.gradle.api.file.FileTree;
+import org.gradle.api.tasks.Classpath;
+import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.OutputDirectory;
+import org.gradle.api.tasks.PathSensitive;
+import org.gradle.api.tasks.PathSensitivity;
+import org.gradle.api.tasks.SkipWhenEmpty;
+import org.gradle.api.tasks.TaskAction;
+import org.gradle.api.tasks.VerificationException;
+import org.gradle.language.base.plugins.LifecycleBasePlugin;
+
+import org.springframework.boot.build.autoconfigure.AutoConfigurationClass;
+
+/**
+ * Task to check the contents of a project's
+ * {@code META-INF/spring/*.AutoConfigure*.imports} files.
+ *
+ * @author Andy Wilkinson
+ */
+public abstract class CheckAutoConfigureImports extends DefaultTask {
+
+	private FileCollection sourceFiles = getProject().getObjects().fileCollection();
+
+	private FileCollection classpath = getProject().getObjects().fileCollection();
+
+	public CheckAutoConfigureImports() {
+		getOutputDirectory().convention(getProject().getLayout().getBuildDirectory().dir(getName()));
+		setGroup(LifecycleBasePlugin.VERIFICATION_GROUP);
+	}
+
+	@InputFiles
+	@SkipWhenEmpty
+	@PathSensitive(PathSensitivity.RELATIVE)
+	public FileTree getSource() {
+		return this.sourceFiles.getAsFileTree()
+			.matching((filter) -> filter.include("META-INF/spring/*.AutoConfigure*.imports"));
+	}
+
+	public void setSource(Object source) {
+		this.sourceFiles = getProject().getObjects().fileCollection().from(source);
+	}
+
+	@Classpath
+	public FileCollection getClasspath() {
+		return this.classpath;
+	}
+
+	public void setClasspath(Object classpath) {
+		this.classpath = getProject().getObjects().fileCollection().from(classpath);
+	}
+
+	@OutputDirectory
+	public abstract DirectoryProperty getOutputDirectory();
+
+	@TaskAction
+	void execute() {
+		Map<String, List<String>> allProblems = new TreeMap<>();
+		for (AutoConfigureImports autoConfigureImports : loadImports()) {
+			List<String> problems = new ArrayList<>();
+			if (!find(autoConfigureImports.annotationName)) {
+				problems.add("Annotation '%s' was not found".formatted(autoConfigureImports.annotationName));
+			}
+			for (String imported : autoConfigureImports.imports) {
+				String importedClassName = imported;
+				if (importedClassName.startsWith("optional:")) {
+					importedClassName = importedClassName.substring("optional:".length());
+				}
+				boolean found = find(importedClassName, (input) -> {
+					if (!correctlyAnnotated(input)) {
+						problems.add("Imported auto-configuration '%s' is not annotated with @AutoConfiguration"
+							.formatted(imported));
+					}
+				});
+				if (!found) {
+					problems.add("Imported auto-configuration '%s' was not found".formatted(importedClassName));
+				}
+
+			}
+			List<String> sortedValues = new ArrayList<>(autoConfigureImports.imports);
+			Collections.sort(sortedValues, (i1, i2) -> {
+				boolean imported1 = i1.startsWith("optional:");
+				boolean imported2 = i2.startsWith("optional:");
+				int comparison = Boolean.compare(imported1, imported2);
+				if (comparison != 0) {
+					return comparison;
+				}
+				return i1.compareTo(i2);
+			});
+			if (!sortedValues.equals(autoConfigureImports.imports)) {
+				File sortedOutputFile = getOutputDirectory().file("sorted-" + autoConfigureImports.fileName)
+					.get()
+					.getAsFile();
+				writeString(sortedOutputFile, sortedValues.stream().collect(Collectors.joining(System.lineSeparator()))
+						+ System.lineSeparator());
+				problems.add(
+						"Entries should be required then optional, each sorted alphabetically (expected content written to '%s')"
+							.formatted(sortedOutputFile.getAbsolutePath()));
+			}
+			if (!problems.isEmpty()) {
+				allProblems.computeIfAbsent(autoConfigureImports.fileName, (unused) -> new ArrayList<>())
+					.addAll(problems);
+			}
+		}
+		File outputFile = getOutputDirectory().file("failure-report.txt").get().getAsFile();
+		writeReport(allProblems, outputFile);
+		if (!allProblems.isEmpty()) {
+			throw new VerificationException(
+					"AutoConfigure….imports checks failed. See '%s' for details".formatted(outputFile));
+		}
+	}
+
+	private List<AutoConfigureImports> loadImports() {
+		return getSource().getFiles().stream().map((file) -> {
+			String fileName = file.getName();
+			String annotationName = fileName.substring(0, fileName.length() - ".imports".length());
+			return new AutoConfigureImports(annotationName, loadImports(file), fileName);
+		}).toList();
+	}
+
+	private List<String> loadImports(File importsFile) {
+		try {
+			return Files.readAllLines(importsFile.toPath());
+		}
+		catch (IOException ex) {
+			throw new UncheckedIOException(ex);
+		}
+	}
+
+	private boolean find(String className) {
+		return find(className, (input) -> {
+		});
+	}
+
+	private boolean find(String className, Consumer<InputStream> handler) {
+		for (File root : this.classpath.getFiles()) {
+			String classFilePath = className.replace(".", "/") + ".class";
+			if (root.isDirectory()) {
+				File classFile = new File(root, classFilePath);
+				if (classFile.isFile()) {
+					try (InputStream input = new FileInputStream(classFile)) {
+						handler.accept(input);
+					}
+					catch (IOException ex) {
+						throw new UncheckedIOException(ex);
+					}
+					return true;
+				}
+			}
+			else {
+				try (JarFile jar = new JarFile(root)) {
+					ZipEntry entry = jar.getEntry(classFilePath);
+					if (entry != null) {
+						try (InputStream input = jar.getInputStream(entry)) {
+							handler.accept(input);
+						}
+						return true;
+					}
+				}
+				catch (IOException ex) {
+					throw new UncheckedIOException(ex);
+				}
+			}
+		}
+		return false;
+	}
+
+	private boolean correctlyAnnotated(InputStream classFile) {
+		return AutoConfigurationClass.of(classFile) != null;
+	}
+
+	private void writeReport(Map<String, List<String>> allProblems, File outputFile) {
+		outputFile.getParentFile().mkdirs();
+		StringBuilder report = new StringBuilder();
+		if (!allProblems.isEmpty()) {
+			allProblems.forEach((fileName, problems) -> {
+				report.append("Found problems in '%s':%n".formatted(fileName));
+				problems.forEach((problem) -> report.append("  - %s%n".formatted(problem)));
+			});
+		}
+		writeString(outputFile, report.toString());
+	}
+
+	private void writeString(File file, String content) {
+		try {
+			Files.writeString(file.toPath(), content);
+		}
+		catch (IOException ex) {
+			throw new UncheckedIOException(ex);
+		}
+	}
+
+	record AutoConfigureImports(String annotationName, List<String> imports, String fileName) {
+
+	}
+
+}

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/DocumentTestSlices.java

@@ -17,17 +17,14 @@
 package org.springframework.boot.build.test.autoconfigure;
 
 import java.io.File;
-import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.io.Reader;
+import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Enumeration;
-import java.util.Properties;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
 
 import org.gradle.api.DefaultTask;
 import org.gradle.api.Task;
@@ -38,9 +35,9 @@ import org.gradle.api.tasks.OutputFile;
 import org.gradle.api.tasks.PathSensitive;
 import org.gradle.api.tasks.PathSensitivity;
 import org.gradle.api.tasks.TaskAction;
+import tools.jackson.databind.json.JsonMapper;
 
-import org.springframework.util.ClassUtils;
-import org.springframework.util.StringUtils;
+import org.springframework.boot.build.test.autoconfigure.TestSliceMetadata.TestSlice;
 
 /**
  * {@link Task} used to document test slices.
@@ -49,16 +46,16 @@ import org.springframework.util.StringUtils;
  */
 public abstract class DocumentTestSlices extends DefaultTask {
 
-	private FileCollection testSlices;
+	private FileCollection testSliceMetadata;
 
 	@InputFiles
 	@PathSensitive(PathSensitivity.RELATIVE)
 	public FileCollection getTestSlices() {
-		return this.testSlices;
+		return this.testSliceMetadata;
 	}
 
 	public void setTestSlices(FileCollection testSlices) {
-		this.testSlices = testSlices;
+		this.testSliceMetadata = testSlices;
 	}
 
 	@OutputFile
@@ -66,61 +63,42 @@ public abstract class DocumentTestSlices extends DefaultTask {
 
 	@TaskAction
 	void documentTestSlices() throws IOException {
-		Set<TestSlice> testSlices = readTestSlices();
+		Map<String, List<TestSlice>> testSlices = readTestSlices();
 		writeTable(testSlices);
 	}
 
-	@SuppressWarnings("unchecked")
-	private Set<TestSlice> readTestSlices() throws IOException {
-		Set<TestSlice> testSlices = new TreeSet<>();
-		for (File metadataFile : this.testSlices) {
-			Properties metadata = new Properties();
-			try (Reader reader = new FileReader(metadataFile)) {
-				metadata.load(reader);
-			}
-			for (String name : Collections.list((Enumeration<String>) metadata.propertyNames())) {
-				testSlices.add(new TestSlice(name,
-						new TreeSet<>(StringUtils.commaDelimitedListToSet(metadata.getProperty(name)))));
-			}
+	private Map<String, List<TestSlice>> readTestSlices() {
+		Map<String, List<TestSlice>> testSlices = new TreeMap<>();
+		for (File metadataFile : this.testSliceMetadata) {
+			JsonMapper mapper = JsonMapper.builder().build();
+			TestSliceMetadata metadata = mapper.readValue(metadataFile, TestSliceMetadata.class);
+			List<TestSlice> slices = new ArrayList<>(metadata.testSlices());
+			Collections.sort(slices, (s1, s2) -> s1.annotation().compareTo(s2.annotation()));
+			testSlices.put(metadata.module(), slices);
 		}
 		return testSlices;
 	}
 
-	private void writeTable(Set<TestSlice> testSlices) throws IOException {
+	private void writeTable(Map<String, List<TestSlice>> testSlicesByModule) throws IOException {
 		File outputFile = getOutputFile().getAsFile().get();
 		outputFile.getParentFile().mkdirs();
 		try (PrintWriter writer = new PrintWriter(new FileWriter(outputFile))) {
-			writer.println("[cols=\"d,a\"]");
+			writer.println("[cols=\"d,d,a\"]");
 			writer.println("|===");
-			writer.println("| Test slice | Imported auto-configuration");
-			for (TestSlice testSlice : testSlices) {
-				writer.println();
-				writer.printf("| `@%s`%n", testSlice.className);
-				writer.println("| ");
-				for (String importedAutoConfiguration : testSlice.importedAutoConfigurations) {
-					writer.printf("`%s`%n", importedAutoConfiguration);
-				}
-			}
+			writer.println("|Module | Test slice | Imported auto-configuration");
+			testSlicesByModule.forEach((module, testSlices) -> {
+				testSlices.forEach((testSlice) -> {
+					writer.println();
+					writer.printf("| `%s`%n", module);
+					writer.printf("| javadoc:%s[format=annotation]%n", testSlice.annotation());
+					writer.println("| ");
+					for (String importedAutoConfiguration : testSlice.importedAutoConfigurations()) {
+						writer.printf("`%s`%n", importedAutoConfiguration);
+					}
+				});
+			});
 			writer.println("|===");
 		}
 	}
 
-	private static final class TestSlice implements Comparable<TestSlice> {
-
-		private final String className;
-
-		private final SortedSet<String> importedAutoConfigurations;
-
-		private TestSlice(String className, SortedSet<String> importedAutoConfigurations) {
-			this.className = ClassUtils.getShortName(className);
-			this.importedAutoConfigurations = importedAutoConfigurations;
-		}
-
-		@Override
-		public int compareTo(TestSlice other) {
-			return this.className.compareTo(other.className);
-		}
-
-	}
-
 }

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/GenerateTestSliceMetadata.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright 2012-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.boot.build.test.autoconfigure;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.Reader;
+import java.io.UncheckedIOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+import javax.inject.Inject;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.Task;
+import org.gradle.api.file.FileCollection;
+import org.gradle.api.file.RegularFileProperty;
+import org.gradle.api.model.ObjectFactory;
+import org.gradle.api.tasks.Classpath;
+import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.OutputFile;
+import org.gradle.api.tasks.PathSensitive;
+import org.gradle.api.tasks.PathSensitivity;
+import org.gradle.api.tasks.SourceSet;
+import org.gradle.api.tasks.TaskAction;
+
+import org.springframework.boot.build.test.autoconfigure.TestSliceMetadata.TestSlice;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.core.type.classreading.MetadataReader;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
+import org.springframework.util.StringUtils;
+
+/**
+ * A {@link Task} for generating metadata describing a project's test slices.
+ *
+ * @author Andy Wilkinson
+ */
+public abstract class GenerateTestSliceMetadata extends DefaultTask {
+
+	private final ObjectFactory objectFactory;
+
+	private FileCollection classpath;
+
+	private FileCollection importsFiles;
+
+	private FileCollection classesDirs;
+
+	@Inject
+	public GenerateTestSliceMetadata(ObjectFactory objectFactory) {
+		this.objectFactory = objectFactory;
+	}
+
+	public void setSourceSet(SourceSet sourceSet) {
+		this.classpath = sourceSet.getRuntimeClasspath();
+		this.importsFiles = this.objectFactory.fileTree()
+			.from(new File(sourceSet.getOutput().getResourcesDir(), "META-INF/spring"));
+		this.importsFiles.filter((file) -> file.getName().endsWith(".imports"));
+		getSpringFactories().set(new File(sourceSet.getOutput().getResourcesDir(), "META-INF/spring.factories"));
+		this.classesDirs = sourceSet.getOutput().getClassesDirs();
+	}
+
+	@OutputFile
+	public abstract RegularFileProperty getOutputFile();
+
+	@InputFiles
+	@PathSensitive(PathSensitivity.RELATIVE)
+	abstract RegularFileProperty getSpringFactories();
+
+	@Classpath
+	FileCollection getClasspath() {
+		return this.classpath;
+	}
+
+	@InputFiles
+	@PathSensitive(PathSensitivity.RELATIVE)
+	FileCollection getImportFiles() {
+		return this.importsFiles;
+	}
+
+	@Classpath
+	FileCollection getClassesDirs() {
+		return this.classesDirs;
+	}
+
+	@TaskAction
+	void generateTestSliceMetadata() throws IOException {
+		TestSliceMetadata metadata = readTestSlices();
+		File outputFile = getOutputFile().getAsFile().get();
+		outputFile.getParentFile().mkdirs();
+		metadata.writeTo(outputFile);
+	}
+
+	private TestSliceMetadata readTestSlices() throws IOException {
+		List<TestSlice> testSlices = new ArrayList<>();
+		try (URLClassLoader classLoader = new URLClassLoader(
+				StreamSupport.stream(this.classpath.spliterator(), false).map(this::toURL).toArray(URL[]::new))) {
+			MetadataReaderFactory metadataReaderFactory = new SimpleMetadataReaderFactory(classLoader);
+			Properties springFactories = readSpringFactories(getSpringFactories().getAsFile().getOrNull());
+			readImportsFiles(springFactories, this.importsFiles);
+			for (File classesDir : this.classesDirs) {
+				testSlices.addAll(readTestSlices(classesDir, metadataReaderFactory, springFactories));
+			}
+		}
+		return new TestSliceMetadata(getProject().getName(), testSlices);
+	}
+
+	/**
+	 * Reads the given imports files and puts them in springFactories. The key is the file
+	 * name, the value is the file contents, split by line, delimited with a comma. This
+	 * is done to mimic the spring.factories structure.
+	 * @param springFactories spring.factories parsed as properties
+	 * @param importsFiles the imports files to read
+	 */
+	private void readImportsFiles(Properties springFactories, FileCollection importsFiles) {
+		for (File file : importsFiles.getFiles()) {
+			try {
+				List<String> lines = removeComments(Files.readAllLines(file.toPath()));
+				String fileNameWithoutExtension = file.getName()
+					.substring(0, file.getName().length() - ".imports".length());
+				springFactories.setProperty(fileNameWithoutExtension,
+						StringUtils.collectionToCommaDelimitedString(lines));
+			}
+			catch (IOException ex) {
+				throw new UncheckedIOException("Failed to read file " + file, ex);
+			}
+		}
+	}
+
+	private List<String> removeComments(List<String> lines) {
+		List<String> result = new ArrayList<>();
+		for (String line : lines) {
+			int commentIndex = line.indexOf('#');
+			if (commentIndex > -1) {
+				line = line.substring(0, commentIndex);
+			}
+			line = line.trim();
+			if (!line.isEmpty()) {
+				result.add(line);
+			}
+		}
+		return result;
+	}
+
+	private URL toURL(File file) {
+		try {
+			return file.toURI().toURL();
+		}
+		catch (MalformedURLException ex) {
+			throw new RuntimeException(ex);
+		}
+	}
+
+	private Properties readSpringFactories(File file) throws IOException {
+		Properties springFactories = new Properties();
+		if (file.isFile()) {
+			try (Reader in = new FileReader(file)) {
+				springFactories.load(in);
+			}
+		}
+		return springFactories;
+	}
+
+	private List<TestSlice> readTestSlices(File classesDir, MetadataReaderFactory metadataReaderFactory,
+			Properties springFactories) throws IOException {
+		try (Stream<Path> classes = Files.walk(classesDir.toPath())) {
+			return classes.filter((path) -> path.toString().endsWith("Test.class"))
+				.map((path) -> getMetadataReader(path, metadataReaderFactory))
+				.filter((metadataReader) -> metadataReader.getClassMetadata().isAnnotation())
+				.map((metadataReader) -> readTestSlice(metadataReader, springFactories))
+				.toList();
+		}
+
+	}
+
+	private MetadataReader getMetadataReader(Path path, MetadataReaderFactory metadataReaderFactory) {
+		try {
+			return metadataReaderFactory.getMetadataReader(new FileSystemResource(path));
+		}
+		catch (IOException ex) {
+			throw new RuntimeException(ex);
+		}
+	}
+
+	private TestSlice readTestSlice(MetadataReader metadataReader, Properties springFactories) {
+		String annotationName = metadataReader.getClassMetadata().getClassName();
+		List<String> importedAutoConfiguration = getImportedAutoConfiguration(springFactories,
+				metadataReader.getAnnotationMetadata());
+		return new TestSlice(annotationName, importedAutoConfiguration);
+	}
+
+	private List<String> getImportedAutoConfiguration(Properties springFactories,
+			AnnotationMetadata annotationMetadata) {
+		Stream<String> importers = findMetaImporters(annotationMetadata);
+		if (annotationMetadata.isAnnotated("org.springframework.boot.autoconfigure.ImportAutoConfiguration")) {
+			importers = Stream.concat(importers, Stream.of(annotationMetadata.getClassName()));
+		}
+		return importers
+			.flatMap((importer) -> StringUtils.commaDelimitedListToSet(springFactories.getProperty(importer)).stream())
+			.toList();
+	}
+
+	private Stream<String> findMetaImporters(AnnotationMetadata annotationMetadata) {
+		return annotationMetadata.getAnnotationTypes()
+			.stream()
+			.filter((annotationType) -> isAutoConfigurationImporter(annotationType, annotationMetadata));
+	}
+
+	private boolean isAutoConfigurationImporter(String annotationType, AnnotationMetadata metadata) {
+		return metadata.getMetaAnnotationTypes(annotationType)
+			.contains("org.springframework.boot.autoconfigure.ImportAutoConfiguration");
+	}
+
+}

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/TestAutoConfigurationPlugin.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-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.boot.build.test.autoconfigure;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.file.ConfigurableFileCollection;
+import org.gradle.api.plugins.JavaPlugin;
+import org.gradle.api.plugins.JavaPluginExtension;
+import org.gradle.api.tasks.SourceSet;
+
+/**
+ * {@link Plugin} for projects that define test auto-configuration. When the
+ * {@link JavaPlugin} is applied it:
+ *
+ * <ul>
+ * <li>Add checks to ensure AutoConfigure*.import files and related annotations are
+ * correct</li>
+ * </ul>
+ *
+ * @author Andy Wilkinson
+ */
+public class TestAutoConfigurationPlugin implements Plugin<Project> {
+
+	@Override
+	public void apply(Project target) {
+		target.getPlugins().withType(JavaPlugin.class, (plugin) -> {
+			target.getTasks().register("checkAutoConfigureImports", CheckAutoConfigureImports.class, (task) -> {
+				SourceSet mainSourceSet = target.getExtensions()
+					.getByType(JavaPluginExtension.class)
+					.getSourceSets()
+					.getByName(SourceSet.MAIN_SOURCE_SET_NAME);
+				task.setSource(mainSourceSet.getResources());
+				ConfigurableFileCollection classpath = target.files(mainSourceSet.getRuntimeClasspath(),
+						target.getConfigurations().getByName(mainSourceSet.getRuntimeClasspathConfigurationName()));
+				task.setClasspath(classpath);
+			});
+		});
+	}
+
+}

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/TestSliceMetadata.java

@@ -17,229 +17,30 @@
 package org.springframework.boot.build.test.autoconfigure;
 
 import java.io.File;
-import java.io.FileReader;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.Reader;
-import java.io.UncheckedIOException;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLClassLoader;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.ArrayList;
 import java.util.List;
-import java.util.Properties;
-import java.util.SortedSet;
-import java.util.TreeSet;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
 
-import javax.inject.Inject;
-
-import org.gradle.api.DefaultTask;
-import org.gradle.api.Task;
-import org.gradle.api.artifacts.Configuration;
-import org.gradle.api.file.FileCollection;
-import org.gradle.api.file.RegularFileProperty;
-import org.gradle.api.model.ObjectFactory;
-import org.gradle.api.tasks.Classpath;
-import org.gradle.api.tasks.InputFile;
-import org.gradle.api.tasks.InputFiles;
-import org.gradle.api.tasks.OutputFile;
-import org.gradle.api.tasks.PathSensitive;
-import org.gradle.api.tasks.PathSensitivity;
-import org.gradle.api.tasks.SourceSet;
-import org.gradle.api.tasks.TaskAction;
-
-import org.springframework.core.CollectionFactory;
-import org.springframework.core.io.FileSystemResource;
-import org.springframework.core.type.AnnotationMetadata;
-import org.springframework.core.type.classreading.MetadataReader;
-import org.springframework.core.type.classreading.MetadataReaderFactory;
-import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
-import org.springframework.util.StringUtils;
+import tools.jackson.databind.SerializationFeature;
+import tools.jackson.databind.json.JsonMapper;
 
 /**
- * A {@link Task} for generating metadata describing a project's test slices.
+ * Metadata describing a module's test slices.
  *
+ * @param module the module's name
+ * @param testSlices the module's test slices
  * @author Andy Wilkinson
  */
-public abstract class TestSliceMetadata extends DefaultTask {
+record TestSliceMetadata(String module, List<TestSlice> testSlices) {
 
-	private final ObjectFactory objectFactory;
-
-	private FileCollection classpath;
-
-	private FileCollection importsFiles;
-
-	private FileCollection classesDirs;
-
-	@Inject
-	public TestSliceMetadata(ObjectFactory objectFactory) {
-		this.objectFactory = objectFactory;
-		Configuration testSliceMetadata = getProject().getConfigurations().maybeCreate("testSliceMetadata");
-		getProject().afterEvaluate((evaluated) -> evaluated.getArtifacts()
-			.add(testSliceMetadata.getName(), getOutputFile(), (artifact) -> artifact.builtBy(this)));
+	static TestSliceMetadata readFrom(File file) {
+		return JsonMapper.builder().build().readValue(file, TestSliceMetadata.class);
 	}
 
-	public void setSourceSet(SourceSet sourceSet) {
-		this.classpath = sourceSet.getRuntimeClasspath();
-		this.importsFiles = this.objectFactory.fileTree()
-			.from(new File(sourceSet.getOutput().getResourcesDir(), "META-INF/spring"));
-		this.importsFiles.filter((file) -> file.getName().endsWith(".imports"));
-		getSpringFactories().set(new File(sourceSet.getOutput().getResourcesDir(), "META-INF/spring.factories"));
-		this.classesDirs = sourceSet.getOutput().getClassesDirs();
+	void writeTo(File file) {
+		JsonMapper.builder().enable(SerializationFeature.INDENT_OUTPUT).build().writeValue(file, this);
 	}
 
-	@OutputFile
-	public abstract RegularFileProperty getOutputFile();
+	record TestSlice(String annotation, List<String> importedAutoConfigurations) {
 
-	@InputFile
-	@PathSensitive(PathSensitivity.RELATIVE)
-	abstract RegularFileProperty getSpringFactories();
-
-	@Classpath
-	FileCollection getClasspath() {
-		return this.classpath;
-	}
-
-	@InputFiles
-	@PathSensitive(PathSensitivity.RELATIVE)
-	FileCollection getImportFiles() {
-		return this.importsFiles;
-	}
-
-	@Classpath
-	FileCollection getClassesDirs() {
-		return this.classesDirs;
-	}
-
-	@TaskAction
-	void documentTestSlices() throws IOException {
-		Properties testSlices = readTestSlices();
-		File outputFile = getOutputFile().getAsFile().get();
-		outputFile.getParentFile().mkdirs();
-		try (FileWriter writer = new FileWriter(outputFile)) {
-			testSlices.store(writer, null);
-		}
-	}
-
-	private Properties readTestSlices() throws IOException {
-		Properties testSlices = CollectionFactory.createSortedProperties(true);
-		try (URLClassLoader classLoader = new URLClassLoader(
-				StreamSupport.stream(this.classpath.spliterator(), false).map(this::toURL).toArray(URL[]::new))) {
-			MetadataReaderFactory metadataReaderFactory = new SimpleMetadataReaderFactory(classLoader);
-			Properties springFactories = readSpringFactories(getSpringFactories().getAsFile().get());
-			readImportsFiles(springFactories, this.importsFiles);
-			for (File classesDir : this.classesDirs) {
-				addTestSlices(testSlices, classesDir, metadataReaderFactory, springFactories);
-			}
-		}
-		return testSlices;
-	}
-
-	/**
-	 * Reads the given imports files and puts them in springFactories. The key is the file
-	 * name, the value is the file contents, split by line, delimited with a comma. This
-	 * is done to mimic the spring.factories structure.
-	 * @param springFactories spring.factories parsed as properties
-	 * @param importsFiles the imports files to read
-	 */
-	private void readImportsFiles(Properties springFactories, FileCollection importsFiles) {
-		for (File file : importsFiles.getFiles()) {
-			try {
-				List<String> lines = removeComments(Files.readAllLines(file.toPath()));
-				String fileNameWithoutExtension = file.getName()
-					.substring(0, file.getName().length() - ".imports".length());
-				springFactories.setProperty(fileNameWithoutExtension,
-						StringUtils.collectionToCommaDelimitedString(lines));
-			}
-			catch (IOException ex) {
-				throw new UncheckedIOException("Failed to read file " + file, ex);
-			}
-		}
-	}
-
-	private List<String> removeComments(List<String> lines) {
-		List<String> result = new ArrayList<>();
-		for (String line : lines) {
-			int commentIndex = line.indexOf('#');
-			if (commentIndex > -1) {
-				line = line.substring(0, commentIndex);
-			}
-			line = line.trim();
-			if (!line.isEmpty()) {
-				result.add(line);
-			}
-		}
-		return result;
-	}
-
-	private URL toURL(File file) {
-		try {
-			return file.toURI().toURL();
-		}
-		catch (MalformedURLException ex) {
-			throw new RuntimeException(ex);
-		}
-	}
-
-	private Properties readSpringFactories(File file) throws IOException {
-		Properties springFactories = new Properties();
-		try (Reader in = new FileReader(file)) {
-			springFactories.load(in);
-		}
-		return springFactories;
-	}
-
-	private void addTestSlices(Properties testSlices, File classesDir, MetadataReaderFactory metadataReaderFactory,
-			Properties springFactories) throws IOException {
-		try (Stream<Path> classes = Files.walk(classesDir.toPath())) {
-			classes.filter((path) -> path.toString().endsWith("Test.class"))
-				.map((path) -> getMetadataReader(path, metadataReaderFactory))
-				.filter((metadataReader) -> metadataReader.getClassMetadata().isAnnotation())
-				.forEach((metadataReader) -> addTestSlice(testSlices, springFactories, metadataReader));
-		}
-
-	}
-
-	private MetadataReader getMetadataReader(Path path, MetadataReaderFactory metadataReaderFactory) {
-		try {
-			return metadataReaderFactory.getMetadataReader(new FileSystemResource(path));
-		}
-		catch (IOException ex) {
-			throw new RuntimeException(ex);
-		}
-	}
-
-	private void addTestSlice(Properties testSlices, Properties springFactories, MetadataReader metadataReader) {
-		testSlices.setProperty(metadataReader.getClassMetadata().getClassName(),
-				StringUtils.collectionToCommaDelimitedString(
-						getImportedAutoConfiguration(springFactories, metadataReader.getAnnotationMetadata())));
-	}
-
-	private SortedSet<String> getImportedAutoConfiguration(Properties springFactories,
-			AnnotationMetadata annotationMetadata) {
-		Stream<String> importers = findMetaImporters(annotationMetadata);
-		if (annotationMetadata.isAnnotated("org.springframework.boot.autoconfigure.ImportAutoConfiguration")) {
-			importers = Stream.concat(importers, Stream.of(annotationMetadata.getClassName()));
-		}
-		return importers
-			.flatMap((importer) -> StringUtils.commaDelimitedListToSet(springFactories.getProperty(importer)).stream())
-			.collect(Collectors.toCollection(TreeSet::new));
-	}
-
-	private Stream<String> findMetaImporters(AnnotationMetadata annotationMetadata) {
-		return annotationMetadata.getAnnotationTypes()
-			.stream()
-			.filter((annotationType) -> isAutoConfigurationImporter(annotationType, annotationMetadata));
-	}
-
-	private boolean isAutoConfigurationImporter(String annotationType, AnnotationMetadata metadata) {
-		return metadata.getMetaAnnotationTypes(annotationType)
-			.contains("org.springframework.boot.autoconfigure.ImportAutoConfiguration");
 	}
 
 }

buildSrc/src/main/java/org/springframework/boot/build/test/autoconfigure/TestSlicePlugin.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2012-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.boot.build.test.autoconfigure;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.attributes.Category;
+import org.gradle.api.attributes.Usage;
+import org.gradle.api.plugins.JavaPlugin;
+import org.gradle.api.plugins.JavaPluginExtension;
+import org.gradle.api.plugins.PluginContainer;
+import org.gradle.api.tasks.SourceSet;
+import org.gradle.api.tasks.TaskProvider;
+
+/**
+ * {@link Plugin} for projects that define one or more test slices. When applied, it:
+ *
+ * <ul>
+ * <li>Applies the {@link TestAutoConfigurationPlugin}
+ * </ul>
+ * Additionally, when the {@link JavaPlugin} is applied it:
+ *
+ * <ul>
+ * <li>Defines a task that produces metadata describing the test slices. The metadata is
+ * made available as an artifact in the {@code testSliceMetadata} configuration
+ * </ul>
+ *
+ * @author Andy Wilkinson
+ */
+public class TestSlicePlugin implements Plugin<Project> {
+
+	private static final String TEST_SLICE_METADATA_CONFIGURATION_NAME = "testSliceMetadata";
+
+	@Override
+	public void apply(Project target) {
+		PluginContainer plugins = target.getPlugins();
+		plugins.apply(TestAutoConfigurationPlugin.class);
+		plugins.withType(JavaPlugin.class, (plugin) -> {
+			TaskProvider<GenerateTestSliceMetadata> generateTestSliceMetadata = target.getTasks()
+				.register("generateTestSliceMetadata", GenerateTestSliceMetadata.class, (task) -> {
+					SourceSet mainSourceSet = target.getExtensions()
+						.getByType(JavaPluginExtension.class)
+						.getSourceSets()
+						.getByName(SourceSet.MAIN_SOURCE_SET_NAME);
+					task.setSourceSet(mainSourceSet);
+					task.getOutputFile().set(target.getLayout().getBuildDirectory().file("test-slice-metadata.json"));
+				});
+			addMetadataArtifact(target, generateTestSliceMetadata);
+		});
+	}
+
+	private void addMetadataArtifact(Project project, TaskProvider<GenerateTestSliceMetadata> task) {
+		project.getConfigurations().consumable(TEST_SLICE_METADATA_CONFIGURATION_NAME, (configuration) -> {
+			configuration.attributes((attributes) -> {
+				attributes.attribute(Category.CATEGORY_ATTRIBUTE,
+						project.getObjects().named(Category.class, Category.DOCUMENTATION));
+				attributes.attribute(Usage.USAGE_ATTRIBUTE,
+						project.getObjects().named(Usage.class, "test-slice-metadata"));
+			});
+		});
+		project.getArtifacts().add(TEST_SLICE_METADATA_CONFIGURATION_NAME, task);
+	}
+
+}

buildSrc/src/main/resources/org/springframework/boot/build/antora/antora-asciidoc-attributes.properties

@@ -116,6 +116,18 @@ apiref-openjdk=https://docs.oracle.com/en/java/javase/17/docs/api
 # === Code Links ===
 
 code-spring-boot=https://github.com/{github-repo}/tree/{github-ref}
-code-spring-boot-autoconfigure-src={code-spring-boot}/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure
+code-spring-boot-autoconfigure-src={code-spring-boot}/core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure
+code-spring-boot-batch-jdbc-src={code-spring-boot}/module/spring-boot-batch-jdbc/src/main/java/org/springframework/boot/batch/jdbc
+code-spring-boot-batch-src={code-spring-boot}/module/spring-boot-batch/src/main/java/org/springframework/boot/batch
+code-spring-boot-freemarker-src={code-spring-boot}/module/spring-boot-freemarker/src/main/java/org/springframework/boot/freemarker
+code-spring-boot-groovy-templates-src={code-spring-boot}/module/spring-boot-groovy-templates/src/main/java/org/springframework/boot/groovy/template
+code-spring-boot-hibernate-src={code-spring-boot}/module/spring-boot-hibernate/src/main/java/org/springframework/boot/hibernate
+code-spring-boot-integration-src={code-spring-boot}/module/spring-boot-integration/src/main/java/org/springframework/boot/integration
+code-spring-boot-jdbc-src={code-spring-boot}/module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc
+code-spring-boot-jooq-src={code-spring-boot}/module/spring-boot-jooq/src/main/java/org/springframework/boot/jooq
+code-spring-boot-jpa-src={code-spring-boot}/module/spring-boot-jpa/src/main/java/org/springframework/boot/jpa
 code-spring-boot-latest=https://github.com/{github-repo}/tree/main
+code-spring-boot-servlet-src={code-spring-boot}/module/spring-boot-servlet/src/main/java/org/springframework/boot/servlet
+code-spring-boot-thymeleaf-src={code-spring-boot}/module/spring-boot-thymeleaf/src/main/java/org/springframework/boot/thymeleaf
+code-spring-boot-webmvc-src={code-spring-boot}/module/spring-boot-webmvc/src/main/java/org/springframework/boot/webmvc
 

buildSrc/src/test/java/org/springframework/boot/build/ConventionsPluginTests.java

@@ -77,7 +77,9 @@ class ConventionsPluginTests {
 			out.println("    id 'org.springframework.boot.conventions'");
 			out.println("}");
 			out.println("version = '1.2.3'");
-			out.println("sourceCompatibility = '17'");
+			out.println("java {");
+			out.println("    sourceCompatibility = '17'");
+			out.println("}");
 			out.println("description 'Test project for manifest customization'");
 			out.println("jar.archiveFileName = 'test.jar'");
 		}
@@ -107,7 +109,9 @@ class ConventionsPluginTests {
 			out.println("    id 'org.springframework.boot.conventions'");
 			out.println("}");
 			out.println("version = '1.2.3'");
-			out.println("sourceCompatibility = '17'");
+			out.println("java {");
+			out.println("    sourceCompatibility = '17'");
+			out.println("}");
 			out.println("description 'Test'");
 		}
 		runGradle("assemble");
@@ -136,7 +140,9 @@ class ConventionsPluginTests {
 			out.println("    id 'org.springframework.boot.conventions'");
 			out.println("}");
 			out.println("version = '1.2.3'");
-			out.println("sourceCompatibility = '17'");
+			out.println("java {");
+			out.println("    sourceCompatibility = '17'");
+			out.println("}");
 			out.println("description 'Test'");
 		}
 		runGradle("assemble");

buildSrc/src/test/java/org/springframework/boot/build/bom/bomr/version/DependencyVersionUpgradeTests.java

@@ -31,6 +31,7 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.ArgumentsProvider;
 import org.junit.jupiter.params.provider.ArgumentsSource;
+import org.junit.jupiter.params.support.ParameterDeclarations;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -244,7 +245,8 @@ class DependencyVersionUpgradeTests {
 	static class InputProvider implements ArgumentsProvider {
 
 		@Override
-		public Stream<? extends Arguments> provideArguments(ExtensionContext context) {
+		public Stream<? extends Arguments> provideArguments(ParameterDeclarations parameterDeclarations,
+				ExtensionContext context) {
 			Method testMethod = context.getRequiredTestMethod();
 			Stream<Arguments> artifactVersions = artifactVersions(testMethod)
 				.map((artifactVersion) -> Arguments.of(VersionType.ARTIFACT_VERSION.parse(artifactVersion.current()),

buildSrc/src/test/java/org/springframework/boot/build/test/autoconfigure/TestSliceMetadataTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-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.boot.build.test.autoconfigure;
+
+import java.io.File;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.boot.build.test.autoconfigure.TestSliceMetadata.TestSlice;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link TestSliceMetadata}.
+ *
+ * @author Andy Wilkinson
+ */
+public class TestSliceMetadataTests {
+
+	@TempDir
+	private File temp;
+
+	@Test
+	void roundtripJson() {
+		TestSliceMetadata source = new TestSliceMetadata("example",
+				List.of(new TestSlice("ExampleOneTest", List.of("com.example.OneAutoConfiguration")),
+						new TestSlice("ExampleTwoTest", List.of("com.example.TwoAutoConfiguration"))));
+		File metadataFile = new File(this.temp, "metadata.json");
+		source.writeTo(metadataFile);
+		TestSliceMetadata readBack = TestSliceMetadata.readFrom(metadataFile);
+		assertThat(source).isEqualTo(readBack);
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/testing/TestFailuresPluginIntegrationTests.java

@@ -166,6 +166,7 @@ class TestFailuresPluginIntegrationTests {
 			writer.println("dependencies {");
 			writer.println("	testImplementation 'org.junit.jupiter:junit-jupiter:5.6.0'");
 			writer.println("	testImplementation 'org.assertj:assertj-core:3.11.1'");
+			writer.println("	testRuntimeOnly 'org.junit.platform:junit-platform-launcher:1.6.0'");
 			writer.println("}");
 			writer.println();
 			writer.println("test {");

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/AbstractBuildLog.java

@@ -21,11 +21,11 @@ import java.util.function.Consumer;
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.LogUpdateEvent;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressEvent;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/ApiVersions.java

@@ -21,7 +21,7 @@ import java.util.stream.IntStream;
 
 import org.jspecify.annotations.Nullable;
 
-import org.springframework.boot.buildpack.platform.docker.type.ApiVersion;
+import org.springframework.boot.buildpack.platform.docker.ApiVersion;
 import org.springframework.util.StringUtils;
 
 /**

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/BuildLog.java

@@ -21,11 +21,11 @@ import java.util.function.Consumer;
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.LogUpdateEvent;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressEvent;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/BuildRequest.java

@@ -28,8 +28,8 @@ import java.util.function.Function;
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/Builder.java

@@ -24,6 +24,7 @@ import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.buildpack.platform.docker.DockerApi;
 import org.springframework.boot.buildpack.platform.docker.DockerLog;
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressEvent;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressPullListener;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressPushListener;
@@ -34,7 +35,6 @@ import org.springframework.boot.buildpack.platform.docker.transport.DockerEngine
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.boot.buildpack.platform.docker.type.ImageArchive;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.IOBiConsumer;
 import org.springframework.boot.buildpack.platform.io.TarArchive;

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/Lifecycle.java

@@ -28,10 +28,10 @@ import com.sun.jna.Platform;
 import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.buildpack.platform.build.Cache.Bind;
+import org.springframework.boot.buildpack.platform.docker.ApiVersion;
 import org.springframework.boot.buildpack.platform.docker.DockerApi;
 import org.springframework.boot.buildpack.platform.docker.LogUpdateEvent;
 import org.springframework.boot.buildpack.platform.docker.configuration.ResolvedDockerHost;
-import org.springframework.boot.buildpack.platform.docker.type.ApiVersion;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerConfig;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerContent;

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/ApiVersion.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.buildpack.platform.docker.type;
+package org.springframework.boot.buildpack.platform.docker;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -28,7 +28,7 @@ import org.springframework.util.Assert;
  *
  * @author Phillip Webb
  * @author Scott Frederick
- * @since 3.4.0
+ * @since 4.0.0
  */
 public final class ApiVersion {
 

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/DockerApi.java

@@ -34,14 +34,12 @@ import org.springframework.boot.buildpack.platform.docker.PushImageUpdateEvent.E
 import org.springframework.boot.buildpack.platform.docker.configuration.DockerConnectionConfiguration;
 import org.springframework.boot.buildpack.platform.docker.transport.HttpTransport;
 import org.springframework.boot.buildpack.platform.docker.transport.HttpTransport.Response;
-import org.springframework.boot.buildpack.platform.docker.type.ApiVersion;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerConfig;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerContent;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerReference;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerStatus;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.boot.buildpack.platform.docker.type.ImageArchive;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.boot.buildpack.platform.io.IOBiConsumer;

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/ImagePlatform.java

@@ -14,19 +14,20 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.buildpack.platform.docker.type;
+package org.springframework.boot.buildpack.platform.docker;
 
 import java.util.Objects;
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.util.Assert;
 
 /**
  * A platform specification for a Docker image.
  *
  * @author Scott Frederick
- * @since 3.4.0
+ * @since 4.0.0
  */
 public class ImagePlatform {
 

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/ApiVersionsTests.java

@@ -20,7 +20,7 @@ import java.util.stream.IntStream;
 
 import org.junit.jupiter.api.Test;
 
-import org.springframework.boot.buildpack.platform.docker.type.ApiVersion;
+import org.springframework.boot.buildpack.platform.docker.ApiVersion;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/BuildRequestTests.java

@@ -37,9 +37,9 @@ import org.junit.jupiter.api.io.TempDir;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.ImageName;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/BuilderTests.java

@@ -31,6 +31,7 @@ import org.springframework.boot.buildpack.platform.docker.DockerApi.ContainerApi
 import org.springframework.boot.buildpack.platform.docker.DockerApi.ImageApi;
 import org.springframework.boot.buildpack.platform.docker.DockerApi.VolumeApi;
 import org.springframework.boot.buildpack.platform.docker.DockerLog;
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressPullListener;
 import org.springframework.boot.buildpack.platform.docker.configuration.DockerRegistryAuthentication;
 import org.springframework.boot.buildpack.platform.docker.transport.DockerEngineException;
@@ -39,7 +40,6 @@ import org.springframework.boot.buildpack.platform.docker.type.ContainerReferenc
 import org.springframework.boot.buildpack.platform.docker.type.ContainerStatus;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.boot.buildpack.platform.docker.type.ImageArchive;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.TarArchive;
 

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/LifecycleTests.java

@@ -41,6 +41,7 @@ import org.springframework.boot.buildpack.platform.docker.DockerApi;
 import org.springframework.boot.buildpack.platform.docker.DockerApi.ContainerApi;
 import org.springframework.boot.buildpack.platform.docker.DockerApi.ImageApi;
 import org.springframework.boot.buildpack.platform.docker.DockerApi.VolumeApi;
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.configuration.DockerConnectionConfiguration;
 import org.springframework.boot.buildpack.platform.docker.configuration.ResolvedDockerHost;
 import org.springframework.boot.buildpack.platform.docker.type.Binding;
@@ -48,7 +49,6 @@ import org.springframework.boot.buildpack.platform.docker.type.ContainerConfig;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerContent;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerReference;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerStatus;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.boot.buildpack.platform.io.IOConsumer;

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/PrintStreamBuildLogTests.java

@@ -25,10 +25,10 @@ import java.util.function.Consumer;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.buildpack.platform.docker.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.LogUpdateEvent;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressEvent;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.util.FileCopyUtils;

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/ApiVersionTests.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.buildpack.platform.docker.type;
+package org.springframework.boot.buildpack.platform.docker;
 
 import java.util.Arrays;
 

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/DockerApiTests.java

@@ -45,14 +45,12 @@ import org.springframework.boot.buildpack.platform.docker.DockerApi.SystemApi;
 import org.springframework.boot.buildpack.platform.docker.DockerApi.VolumeApi;
 import org.springframework.boot.buildpack.platform.docker.transport.HttpTransport;
 import org.springframework.boot.buildpack.platform.docker.transport.HttpTransport.Response;
-import org.springframework.boot.buildpack.platform.docker.type.ApiVersion;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerConfig;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerContent;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerReference;
 import org.springframework.boot.buildpack.platform.docker.type.ContainerStatus;
 import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.boot.buildpack.platform.docker.type.ImageArchive;
-import org.springframework.boot.buildpack.platform.docker.type.ImagePlatform;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.boot.buildpack.platform.io.Content;

buildpack/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/ImagePlatformTests.java

@@ -14,12 +14,13 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.buildpack.platform.docker.type;
+package org.springframework.boot.buildpack.platform.docker;
 
 import java.io.IOException;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.buildpack.platform.docker.type.Image;
 import org.springframework.boot.buildpack.platform.json.AbstractJsonTests;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -64,7 +65,7 @@ class ImagePlatformTests extends AbstractJsonTests {
 	}
 
 	private Image getImage() throws IOException {
-		return Image.of(getContent("image.json"));
+		return Image.of(getContent("type/image.json"));
 	}
 
 }

config/checkstyle/checkstyle-suppressions.xml

@@ -79,4 +79,7 @@
 	<suppress files="EntityManagerFactoryBuilder\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
 	<suppress files="DockerApi\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
 	<suppress files="InvocationContext\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
+	<!-- https://github.com/apache/logging-log4j2/issues/2769#issuecomment-3049020222 -->
+	<suppress files="SpringProfileArbiter\.java" checks="SpringMethodVisibility"/>
+	<suppress files="StructuredLogLayout\.java" checks="SpringMethodVisibility"/>
 </suppressions>

config/checkstyle/checkstyle.xml

@@ -6,7 +6,10 @@
 	<module name="SuppressionFilter">
 		<property name="file" value="${config_loc}/checkstyle-suppressions.xml"/>
 	</module>
-	<module name="io.spring.javaformat.checkstyle.SpringChecks" />
+	<module name="io.spring.javaformat.checkstyle.SpringChecks">
+		<property name="avoidStaticImportExcludes"
+			value="org.springframework.boot.autoconfigure.AutoConfigurationImportedCondition.importedAutoConfiguration" />
+	</module>
 	<module name="io.spring.javaformat.checkstyle.check.SpringHeaderCheck">
 		<property name="headerFile" value="${config_loc}/checkstyle-header.txt"/>
 	</module>

config/checkstyle/import-control.xml

@@ -17,7 +17,7 @@
 	<subpackage name="ansi">
 		<disallow pkg="org.springframework.boot" exact-match="true"/>
 	</subpackage>
-	<subpackage name="avilability">
+	<subpackage name="availability">
 		<disallow pkg="org.springframework.boot" exact-match="true"/>
 	</subpackage>
 	<subpackage name="bootstrap">
@@ -91,8 +91,6 @@
 		<disallow pkg="jakarta.servlet" />
 
 		<!-- Common -->
-		<subpackage name="client">
-		</subpackage>
 		<subpackage name="context">
 			<allow pkg="org.springframework.context" />
 			<subpackage name="servlet">
@@ -111,6 +109,10 @@
 					<allow pkg="org.springframework.boot.web.servlet" />
 				</subpackage>
 			</subpackage>
+			<subpackage name="client">
+				<allow pkg="jakarta.servlet" />
+				<allow pkg="org.springframework.context" />
+			</subpackage>
 			<subpackage name="context">
 				<allow pkg="org.springframework.context" />
 			</subpackage>

config/detekt/config.yml

@@ -19,7 +19,7 @@ style:
     active: true
   NewLineAtEndOfFile:
     active: true
-  UnusedImports:
+  UnusedImport:
     active: true
   WildcardImport:
     active: true

configuration-metadata/spring-boot-configuration-metadata-changelog-generator/build.gradle

@@ -136,20 +136,25 @@ def dependenciesOf(String version) {
 			modules += [
 				"spring-boot-jersey"
 			]
-			if (version.equals("4.0.0-M1")) {
-				modules += [
-					"spring-boot-metrics",
-					"spring-boot-observation",
-					"spring-boot-tracing"
-				]
-			}
-			else {
-				modules += [
-					"spring-boot-micrometer-metrics",
-					"spring-boot-micrometer-observation",
-					"spring-boot-micrometer-tracing"
-				]
-			}
+		}
+		if (version.equals("4.0.0-M1")) {
+			modules += [
+				"spring-boot-metrics",
+				"spring-boot-observation",
+				"spring-boot-tracing"
+			]
+		}
+		else {
+			modules += [
+				"spring-boot-micrometer-metrics",
+				"spring-boot-micrometer-observation",
+				"spring-boot-micrometer-tracing"
+			]
+		}
+		if (version.equals("4.0.0-RC1")) {
+			modules += [
+				"spring-boot-batch-jdbc"
+			]
 		}
 		return modules
 	}

core/spring-boot-autoconfigure/build.gradle

@@ -56,3 +56,7 @@ dependencies {
 test {
 	jvmArgs += "--add-opens=java.base/java.net=ALL-UNNAMED"
 }
+
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}

core/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/AutoConfigurationExcludeFilterTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.autoconfigure;
 import java.util.Collections;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 
@@ -42,7 +43,7 @@ class AutoConfigurationExcludeFilterTests {
 
 	private static final Class<?> FILTERED = ExampleFilteredAutoConfiguration.class;
 
-	private AnnotationConfigApplicationContext context;
+	private @Nullable AnnotationConfigApplicationContext context;
 
 	@AfterEach
 	void cleanUp() {
@@ -56,7 +57,10 @@ class AutoConfigurationExcludeFilterTests {
 		this.context = new AnnotationConfigApplicationContext(Config.class);
 		assertThat(this.context.getBeansOfType(String.class)).hasSize(1);
 		assertThat(this.context.getBean(String.class)).isEqualTo("test");
-		assertThatExceptionOfType(NoSuchBeanDefinitionException.class).isThrownBy(() -> this.context.getBean(FILTERED));
+		assertThatExceptionOfType(NoSuchBeanDefinitionException.class).isThrownBy(() -> {
+			assertThat(this.context).isNotNull();
+			this.context.getBean(FILTERED);
+		});
 	}
 
 	@Configuration(proxyBeanMethods = false)

core/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/AutoConfigurationImportSelectorTests.java

@@ -28,6 +28,7 @@ import java.util.Set;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -83,39 +84,35 @@ class AutoConfigurationImportSelectorTests {
 	void importsAreSelectedWhenUsingEnableAutoConfiguration() {
 		String[] imports = selectImports(BasicEnableAutoConfiguration.class);
 		assertThat(imports).hasSameSizeAs(getAutoConfigurationClassNames());
-		assertThat(this.importSelector.getLastEvent().getExclusions()).isEmpty();
+		assertThat(getLastEvent().getExclusions()).isEmpty();
 	}
 
 	@Test
 	void classExclusionsAreApplied() {
 		String[] imports = selectImports(EnableAutoConfigurationWithClassExclusions.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 1);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains(SeventhAutoConfiguration.class.getName());
+		assertThat(getLastEvent().getExclusions()).contains(SeventhAutoConfiguration.class.getName());
 	}
 
 	@Test
 	void classExclusionsAreAppliedWhenUsingSpringBootApplication() {
 		String[] imports = selectImports(SpringBootApplicationWithClassExclusions.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 1);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains(SeventhAutoConfiguration.class.getName());
+		assertThat(getLastEvent().getExclusions()).contains(SeventhAutoConfiguration.class.getName());
 	}
 
 	@Test
 	void classNamesExclusionsAreApplied() {
 		String[] imports = selectImports(EnableAutoConfigurationWithClassNameExclusions.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 1);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains("com.example.one.FirstAutoConfiguration");
+		assertThat(getLastEvent().getExclusions()).contains("com.example.one.FirstAutoConfiguration");
 	}
 
 	@Test
 	void classNamesExclusionsAreAppliedWhenUsingSpringBootApplication() {
 		String[] imports = selectImports(SpringBootApplicationWithClassNameExclusions.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 1);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains("com.example.three.ThirdAutoConfiguration");
+		assertThat(getLastEvent().getExclusions()).contains("com.example.three.ThirdAutoConfiguration");
 	}
 
 	@Test
@@ -123,8 +120,7 @@ class AutoConfigurationImportSelectorTests {
 		this.environment.setProperty("spring.autoconfigure.exclude", "com.example.three.ThirdAutoConfiguration");
 		String[] imports = selectImports(BasicEnableAutoConfiguration.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 1);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains("com.example.three.ThirdAutoConfiguration");
+		assertThat(getLastEvent().getExclusions()).contains("com.example.three.ThirdAutoConfiguration");
 	}
 
 	@Test
@@ -151,8 +147,8 @@ class AutoConfigurationImportSelectorTests {
 	private void testSeveralPropertyExclusionsAreApplied() {
 		String[] imports = selectImports(BasicEnableAutoConfiguration.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 2);
-		assertThat(this.importSelector.getLastEvent().getExclusions())
-			.contains("com.example.two.SecondAutoConfiguration", "com.example.four.FourthAutoConfiguration");
+		assertThat(getLastEvent().getExclusions()).contains("com.example.two.SecondAutoConfiguration",
+				"com.example.four.FourthAutoConfiguration");
 	}
 
 	@Test
@@ -160,9 +156,8 @@ class AutoConfigurationImportSelectorTests {
 		this.environment.setProperty("spring.autoconfigure.exclude", "com.example.one.FirstAutoConfiguration");
 		String[] imports = selectImports(EnableAutoConfigurationWithClassAndClassNameExclusions.class);
 		assertThat(imports).hasSize(getAutoConfigurationClassNames().size() - 3);
-		assertThat(this.importSelector.getLastEvent().getExclusions()).contains(
-				"com.example.one.FirstAutoConfiguration", "com.example.five.FifthAutoConfiguration",
-				SeventhAutoConfiguration.class.getName());
+		assertThat(getLastEvent().getExclusions()).contains("com.example.one.FirstAutoConfiguration",
+				"com.example.five.FifthAutoConfiguration", SeventhAutoConfiguration.class.getName());
 	}
 
 	@Test
@@ -202,7 +197,7 @@ class AutoConfigurationImportSelectorTests {
 		this.environment.setProperty("spring.autoconfigure.exclude",
 				"org.springframework.boot.autoconfigure.DoesNotExist2");
 		selectImports(EnableAutoConfigurationWithAbsentClassNameExclude.class);
-		assertThat(this.importSelector.getLastEvent().getExclusions()).containsExactlyInAnyOrder(
+		assertThat(getLastEvent().getExclusions()).containsExactlyInAnyOrder(
 				"org.springframework.boot.autoconfigure.DoesNotExist1",
 				"org.springframework.boot.autoconfigure.DoesNotExist2");
 	}
@@ -269,11 +264,17 @@ class AutoConfigurationImportSelectorTests {
 		importSelector.setBeanClassLoader(Thread.currentThread().getContextClassLoader());
 	}
 
+	private AutoConfigurationImportEvent getLastEvent() {
+		AutoConfigurationImportEvent result = this.importSelector.getLastEvent();
+		assertThat(result).isNotNull();
+		return result;
+	}
+
 	private final class TestAutoConfigurationImportSelector extends AutoConfigurationImportSelector {
 
-		private AutoConfigurationImportEvent lastEvent;
+		private @Nullable AutoConfigurationImportEvent lastEvent;
 
-		TestAutoConfigurationImportSelector(Class<?> autoConfigurationAnnotation) {
+		TestAutoConfigurationImportSelector(@Nullable Class<?> autoConfigurationAnnotation) {
 			super(autoConfigurationAnnotation);
 		}
 
@@ -287,7 +288,7 @@ class AutoConfigurationImportSelectorTests {
 			return Collections.singletonList((event) -> this.lastEvent = event);
 		}
 
-		AutoConfigurationImportEvent getLastEvent() {
+		@Nullable AutoConfigurationImportEvent getLastEvent() {
 			return this.lastEvent;
 		}
 
@@ -297,6 +298,7 @@ class AutoConfigurationImportSelectorTests {
 
 		private final Set<String> nonMatching = new HashSet<>();
 
+		@SuppressWarnings("NullAway.Init")
 		private BeanFactory beanFactory;
 
 		TestAutoConfigurationImportFilter(String[] configurations, int... nonMatching) {
@@ -306,7 +308,8 @@ class AutoConfigurationImportSelectorTests {
 		}
 
 		@Override
-		public boolean[] match(String[] autoConfigurationClasses, AutoConfigurationMetadata autoConfigurationMetadata) {
+		public boolean[] match(@Nullable String[] autoConfigurationClasses,
+				AutoConfigurationMetadata autoConfigurationMetadata) {
 			boolean[] result = new boolean[autoConfigurationClasses.length];
 			for (int i = 0; i < result.length; i++) {
 				result[i] = !this.nonMatching.contains(autoConfigurationClasses[i]);

core/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/AutoConfigurationSorterTests.java

@@ -26,6 +26,7 @@ import java.util.Properties;
 import java.util.Set;
 import java.util.function.UnaryOperator;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -251,10 +252,14 @@ class AutoConfigurationSorterTests {
 	}
 
 	private void addAutoConfigureAfter(Properties properties, String className, AnnotationMetadata annotationMetadata) {
-		Map<String, Object> autoConfigureAfter = annotationMetadata
+		Map<String, @Nullable Object> autoConfigureAfter = annotationMetadata
 			.getAnnotationAttributes(AutoConfigureAfter.class.getName(), true);
 		if (autoConfigureAfter != null) {
-			String value = merge((String[]) autoConfigureAfter.get("value"), (String[]) autoConfigureAfter.get("name"));
+			String[] valueAttribute = (String[]) autoConfigureAfter.get("value");
+			String[] nameAttribute = (String[]) autoConfigureAfter.get("name");
+			assertThat(valueAttribute).isNotNull();
+			assertThat(nameAttribute).isNotNull();
+			String value = merge(valueAttribute, nameAttribute);
 			if (!value.isEmpty()) {
 				properties.put(className + ".AutoConfigureAfter", value);
 			}
@@ -263,11 +268,14 @@ class AutoConfigurationSorterTests {
 
 	private void addAutoConfigureBefore(Properties properties, String className,
 			AnnotationMetadata annotationMetadata) {
-		Map<String, Object> autoConfigureBefore = annotationMetadata
+		Map<String, @Nullable Object> autoConfigureBefore = annotationMetadata
 			.getAnnotationAttributes(AutoConfigureBefore.class.getName(), true);
 		if (autoConfigureBefore != null) {
-			String value = merge((String[]) autoConfigureBefore.get("value"),
-					(String[]) autoConfigureBefore.get("name"));
+			String[] valueAttribute = (String[]) autoConfigureBefore.get("value");
+			String[] nameAttribute = (String[]) autoConfigureBefore.get("name");
+			assertThat(valueAttribute).isNotNull();
+			assertThat(nameAttribute).isNotNull();
+			String value = merge(valueAttribute, nameAttribute);
 			if (!value.isEmpty()) {
 				properties.put(className + ".AutoConfigureBefore", value);
 			}
@@ -275,7 +283,7 @@ class AutoConfigurationSorterTests {
 	}
 
 	private void addAutoConfigureOrder(Properties properties, String className, AnnotationMetadata annotationMetadata) {
-		Map<String, Object> autoConfigureOrder = annotationMetadata
+		Map<String, @Nullable Object> autoConfigureOrder = annotationMetadata
 			.getAnnotationAttributes(AutoConfigureOrder.class.getName());
 		if (autoConfigureOrder != null) {
 			Integer order = (Integer) autoConfigureOrder.get("order");