Use JDK 24 toolchain to run Gradle and Java-related tasks

Author: marcphilipp

.github/actions/run-gradle/action.yml

@@ -15,7 +15,7 @@ runs:
       id: setup-gradle-jdk
       with:
         distribution: temurin
-        java-version: 21
+        java-version: 24
         check-latest: true
     - uses: gradle/actions/setup-gradle@8379f6a1328ee0e06e2bb424dadb7b159856a326 # v4.4.0
       with:

.github/workflows/cross-version.yml

@@ -22,8 +22,6 @@ jobs:
       fail-fast: false
       matrix:
         jdk:
-        - version: 24
-          type: ga
         - version: 25
           type: ea
     name: "OpenJDK ${{ matrix.jdk.version }} (${{ matrix.jdk.release || matrix.jdk.type }})"
@@ -71,7 +69,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        jdk: [ 21 ]
+        jdk: [ 24 ]
     name: "OpenJ9 ${{ matrix.jdk }}"
     runs-on: ubuntu-latest
     steps:

.github/workflows/gradle-dependency-submission.yml

@@ -22,7 +22,7 @@ jobs:
       uses: actions/setup-java@c5195efecf7bdfc987ee8bae7a71cb8b11521c00 # v4.7.1
       with:
         distribution: temurin
-        java-version: 21
+        java-version: 24
         check-latest: true
     - name: Generate and submit dependency graph
       uses: gradle/actions/dependency-submission@8379f6a1328ee0e06e2bb424dadb7b159856a326 # v4.4.0

.github/workflows/main.yml

@@ -29,7 +29,7 @@ jobs:
       with:
         distribution: graalvm-community
         version: 'latest'
-        java-version: '21'
+        java-version: '24'
         github-token: ${{ secrets.GITHUB_TOKEN }}
     - name: Build
       uses: ./.github/actions/main-build

.github/workflows/release.yml

@@ -87,7 +87,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@c5195efecf7bdfc987ee8bae7a71cb8b11521c00 # v4.7.1
         with:
-          java-version: 21
+          java-version: 24
           distribution: temurin
       - uses: sbt/setup-sbt@69a46ab4acd4316aa16e68d91a9249a98d7e78d5 # v1.1.8
       - name: Update JUnit dependencies in samples
@@ -245,7 +245,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@c5195efecf7bdfc987ee8bae7a71cb8b11521c00 # v4.7.1
         with:
-          java-version: 21
+          java-version: 24
           distribution: temurin
       - uses: sbt/setup-sbt@69a46ab4acd4316aa16e68d91a9249a98d7e78d5 # v1.1.8
       - name: Update JUnit dependencies in samples

README.md

@@ -70,7 +70,7 @@ task outputs from previous CI builds.
 
 ## Building from Source
 
-You need [JDK 21] to build JUnit. [Gradle toolchains] are used to detect and
+You need [JDK 24] to build JUnit. [Gradle toolchains] are used to detect and
 potentially download additional JDKs for compilation and test execution.
 
 All modules can be _built_ and _tested_ with the [Gradle Wrapper] using the following command:
@@ -100,7 +100,7 @@ of the JUnit Platform, JUnit Jupiter, and JUnit Vintage.
 [Gradle Wrapper]: https://docs.gradle.org/current/userguide/gradle_wrapper.html#sec:using_wrapper
 [JaCoCo]: https://www.eclemma.org/jacoco/
 [Javadoc]: https://junit.org/junit5/docs/current/api/
-[JDK 21]: https://javaalmanac.io/jdk/21/
+[JDK 24]: https://javaalmanac.io/jdk/24/
 [Release Notes]: https://junit.org/junit5/docs/current/release-notes/
 [Samples]: https://github.com/junit-team/junit5-samples
 [StackOverflow]: https://stackoverflow.com/questions/tagged/junit5

gradle/base/dsl-extensions/build.gradle.kts

@@ -1,3 +1,14 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21
+
 plugins {
     `kotlin-dsl`
 }
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+}
+
+kotlin {
+    compilerOptions.jvmTarget = JVM_21
+}

gradle/gradle-daemon-jvm.properties

@@ -1,2 +1,2 @@
 #This file is generated by updateDaemonJvm
-toolchainVersion=21
+toolchainVersion=24

gradle/plugins/build-parameters/build.gradle.kts

@@ -4,6 +4,11 @@ plugins {
 
 group = "junitbuild"
 
+java {
+	sourceCompatibility = JavaVersion.VERSION_21
+	targetCompatibility = JavaVersion.VERSION_21
+}
+
 buildParameters {
 	pluginId("junitbuild.build-parameters")
 	bool("ci") {

gradle/plugins/code-generator/build.gradle.kts

@@ -1,3 +1,5 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21
+
 plugins {
 	`kotlin-dsl`
 }
@@ -10,3 +12,12 @@ dependencies {
 	implementation(libs.jackson.module.kotlin)
 	implementation(libs.jte)
 }
+
+java {
+	sourceCompatibility = JavaVersion.VERSION_21
+	targetCompatibility = JavaVersion.VERSION_21
+}
+
+kotlin {
+	compilerOptions.jvmTarget = JVM_21
+}