Bump JDK baseline to 17

.github/actions/setup-test-jdk/action.yml

@@ -15,3 +15,10 @@ runs:
         check-latest: true
     - shell: bash
       run: echo "JDK8=$JAVA_HOME" >> $GITHUB_ENV
+    - uses: actions/setup-java@7a6d8a8234af8eb26422e24e3006232cccaa061b # v4
+      with:
+        distribution: ${{ inputs.distribution }}
+        java-version: 17
+        check-latest: true
+    - shell: bash
+      run: echo "JDK17=$JAVA_HOME" >> $GITHUB_ENV

documentation/documentation.gradle.kts

@@ -26,8 +26,8 @@ val modularProjects: List<Project> by rootProject
 modularProjects.forEach { evaluationDependsOn(it.path) }
 
 javaLibrary {
-	mainJavaVersion = JavaVersion.VERSION_1_8
-	testJavaVersion = JavaVersion.VERSION_1_8
+	mainJavaVersion = JavaVersion.VERSION_17
+	testJavaVersion = JavaVersion.VERSION_17
 }
 
 val apiReport = configurations.dependencyScope("apiReport")

gradle.properties

@@ -20,7 +20,7 @@ org.gradle.jvmargs=-Xmx1g -XX:MaxMetaspaceSize=512m -XX:+HeapDumpOnOutOfMemoryEr
 org.gradle.caching=true
 org.gradle.parallel=true
 org.gradle.configuration-cache.parallel=true
-org.gradle.java.installations.fromEnv=JDK8,JDK18,JDK19,JDK20,JDK21,JDK22,JDK23,JDK24
+org.gradle.java.installations.fromEnv=JDK8,JDK17,JDK21,JDK23,JDK24,JDK25
 org.gradle.kotlin.dsl.allWarningsAsErrors=true
 
 # Test Distribution

gradle/plugins/common/src/main/kotlin/JavaLibraryExtension.kt

@@ -1,7 +1,7 @@
 import org.gradle.api.JavaVersion
 
 open class JavaLibraryExtension {
-    var mainJavaVersion: JavaVersion = JavaVersion.VERSION_1_8
+    var mainJavaVersion: JavaVersion = JavaVersion.VERSION_17
     var testJavaVersion: JavaVersion = JavaVersion.VERSION_21
     var configureRelease: Boolean = true
 }

gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts

@@ -184,10 +184,8 @@ val compileModule by tasks.registering(JavaCompile::class) {
 	enabled = project in modularProjects
 	source = fileTree(combinedModuleSourceDir).builtBy(prepareModuleSourceDir)
 	destinationDirectory = moduleOutputDir
-	sourceCompatibility = "9"
-	targetCompatibility = "9"
 	classpath = files()
-	options.release = 9
+	options.release = 17
 	options.compilerArgs.addAll(listOf(
 			// Suppress warnings for automatic modules: org.apiguardian.api, org.opentest4j
 			"-Xlint:all,-requires-automatic,-requires-transitive-automatic",
@@ -262,17 +260,14 @@ tasks.withType<JavaCompile>().configureEach {
 }
 
 tasks.compileJava {
-	// See: https://docs.oracle.com/en/java/javase/12/tools/javac.html
 	options.compilerArgs.addAll(listOf(
 			"-Xlint:all", // Enables all recommended warnings.
 			"-Werror", // Terminates compilation when warnings occur.
-			// Required for compatibility with Java 8's reflection APIs (see https://github.com/junit-team/junit5/issues/3797).
 			"-parameters", // Generates metadata for reflection on method parameters.
 	))
 }
 
 tasks.compileTestJava {
-	// See: https://docs.oracle.com/en/java/javase/12/tools/javac.html
 	options.compilerArgs.addAll(listOf(
 			"-Xlint", // Enables all recommended warnings.
 			"-Xlint:-overrides", // Disables "method overrides" warnings.

junit-platform-commons/junit-platform-commons.gradle.kts

@@ -1,8 +1,5 @@
-import junitbuild.java.UpdateJarAction
-
 plugins {
 	id("junitbuild.java-library-conventions")
-	id("junitbuild.java-multi-release-sources")
 	id("junitbuild.native-image-properties")
 	`java-test-fixtures`
 }
@@ -14,28 +11,3 @@ dependencies {
 
 	compileOnlyApi(libs.apiguardian)
 }
-
-tasks.jar {
-	val release9ClassesDir = sourceSets.mainRelease9.get().output.classesDirs.singleFile
-	inputs.dir(release9ClassesDir).withPathSensitivity(PathSensitivity.RELATIVE)
-	doLast(objects.newInstance(UpdateJarAction::class).apply {
-		javaLauncher = javaToolchains.launcherFor(java.toolchain)
-		args.addAll(
-			"--file", archiveFile.get().asFile.absolutePath,
-			"--release", "9",
-			"-C", release9ClassesDir.absolutePath, "."
-		)
-	})
-}
-
-tasks.codeCoverageClassesJar {
-	exclude("org/junit/platform/commons/util/ModuleUtils.class")
-	exclude("org/junit/platform/commons/util/PackageNameUtils.class")
-	exclude("org/junit/platform/commons/util/ServiceLoaderUtils.class")
-}
-
-eclipse {
-	classpath {
-		sourceSets -= project.sourceSets.mainRelease9.get()
-	}
-}