Improved java CI

.github/workflows/java-ci.yml

@@ -7,15 +7,26 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout latest code
+        uses: actions/checkout@v2
+
       - name: Set up JDK 16
         uses: actions/setup-java@v2
         with:
-          java-version: '16'
           distribution: 'adopt'
-      - name: Validate Gradle wrapper
-        uses: gradle/wrapper-validation-action@e6e38bacfdf1a337459f332974bb2327a31aaf4b
+          java-version: 16
+
+      - name: Setup build cache
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+
       - run: ./gradlew build
+      - run: ./gradlew build # Run it twice because special gradle sucks
+
       - uses: actions/upload-artifact@v2
         with:
           name: Package