build only on java 25 and download it if needed (#2735)

Co-authored-by: Copilot <copilot@github.com>

Author: riccardobl

.github/workflows/main.yml

@@ -240,8 +240,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest,windows-latest,macOS-latest]
-        jdk: [17, 21, 25]
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+        jdk: [25]
         include:
           - os: ubuntu-latest
             osName: linux
@@ -252,23 +252,13 @@ jobs:
           - os: macOS-latest
             osName: mac
             deploy: false
-          - jdk: 17
-            deploy: false
-          - jdk: 21
-            deploy: false
 
     steps:
       - name: Clone the repo
         uses: actions/checkout@v6.0.2
         with:
           fetch-depth: 1
 
-      - name: Setup the java environment
-        uses: actions/setup-java@v5.2.0
-        with:
-          distribution: 'temurin'
-          java-version: ${{ matrix.jdk }}
-
       - name: Download natives for android
         uses: actions/download-artifact@v8.0.1
         with:

common.gradle

@@ -18,15 +18,17 @@ version = jmeFullVersion
 java {
     sourceCompatibility = JavaVersion.VERSION_1_8
     targetCompatibility = JavaVersion.VERSION_1_8
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(25)
+        vendor = JvmVendorSpec.ADOPTIUM
+    }
 }
 
 tasks.withType(JavaCompile) { // compile-time options:
     //options.compilerArgs << '-Xlint:deprecation' // to show deprecation warnings
     options.compilerArgs << '-Xlint:unchecked'
     options.encoding = 'UTF-8'
-    if (JavaVersion.current().isCompatibleWith(JavaVersion.VERSION_1_10)) {
-        options.release = 8
-    }
+    options.release = 8
 }
 
 repositories {

gradle.properties

@@ -15,6 +15,9 @@ includeBranchInVersion = false
 # specify if JavaDoc should be built
 buildJavaDoc = true
 
+# Let Gradle fetch missing JDKs for toolchains automatically.
+org.gradle.java.installations.auto-download=true
+
 # specify if SDK and Native libraries get built
 buildNativeProjects = false
 buildAndroidExamples = false

settings.gradle

@@ -1,6 +1,10 @@
 /**
  * This is the global settings file used by all subprojects.
  **/
+plugins {
+    id 'org.gradle.toolchains.foojay-resolver-convention' version '1.0.0'
+}
+
 rootProject.name = 'jmonkeyengine'
 
 // Core classes, should work on all java platforms