build(deps): use JDK11 everywhere, validate it in build

API31 can't be attempted until JDK11 is in place

.github/workflows/linux_build.yml

@@ -15,6 +15,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/macos_build.yml

@@ -16,6 +16,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22
@@ -96,6 +102,12 @@ jobs:
         name: rsdroid-instrumented
         path: rsdroid-instrumented/build/outputs/apk
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/publish_library.yml

@@ -10,6 +10,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/publish_testing.yml

@@ -11,6 +11,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/robolectric_build.yml

@@ -25,6 +25,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22
@@ -136,6 +142,12 @@ jobs:
                   exit 1
               fi
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/update_gradle_wrapper.yml

@@ -14,6 +14,12 @@ jobs:
         with:
           submodules: 'recursive'
 
+      - name: Configure JDK 1.11
+        uses: actions/setup-java@v3
+        with:
+          distribution: "adopt"
+          java-version: "11" # minimum for Android API31
+
       - uses: nttld/setup-ndk@v1
         with:
           ndk-version: r22

.github/workflows/windows_build.yml

@@ -13,6 +13,12 @@ jobs:
 
     - uses: actions/checkout@v2
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

.github/workflows/windows_pure_build.yml

@@ -13,6 +13,12 @@ jobs:
     - name: Fetch submodules
       run:  git submodule update --init --recursive --remote --force
 
+    - name: Configure JDK 1.11
+      uses: actions/setup-java@v3
+      with:
+        distribution: "adopt"
+        java-version: "11" # minimum for Android API31
+
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r22

build.gradle

@@ -1,3 +1,5 @@
+import org.gradle.internal.jvm.Jvm
+
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
     ext {
@@ -39,4 +41,20 @@ allprojects {
 
 task clean(type: Delete) {
     delete rootProject.buildDir
+}
+
+
+ext {
+    jvmVersion = Jvm.current().javaVersion.majorVersion
+    if (jvmVersion != "11" && jvmVersion != "14" && jvmVersion != "16") {
+        println "\n\n\n"
+        println "**************************************************************************************************************"
+        println "\n\n\n"
+        println "ERROR: Anki-Android-Backend builds with JVM version 11, 14, or 16."
+        println "  Incompatible major version detected: '" + jvmVersion + "'"
+        println "\n\n\n"
+        println "**************************************************************************************************************"
+        println "\n\n\n"
+        System.exit(1)
+    }
 }