#540 Cache SDKman (#554)

IMPORTANT: Only use SDKman provided Java - System JDK no longer installed!

.github/workflows/maven.yml

@@ -17,6 +17,8 @@
 name: Build
 
 on:
+  # Enable manual re-run
+  workflow_dispatch: { }
   push:
     branches: [ main ]
   pull_request:
@@ -32,11 +34,12 @@ jobs:
         with:
           submodules: 'true'
 
-      - name: 'Set up Java'
-        uses: actions/setup-java@v2
+      - name: Cache SDKMan
+        id: cache-sdkman
+        uses: actions/cache@v4
         with:
-          java-version: 21
-          distribution: 'temurin'
+          path: ~/.sdkman
+          key: ${{ runner.os }}-sdkman
 
       - name: 'Cache Maven packages'
         uses: actions/cache@v3
@@ -45,21 +48,20 @@ jobs:
           key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
           restore-keys: ${{ runner.os }}-m2
 
-      #- name: Cache SDKMan
-      #  id: cache-sdkman
-      #  uses: actions/cache@v4
-      #  with:
-      #    path: ~/.sdkman
-      #    key: ${{ runner.os }}-sdkman
-
-      - name: 'Build project'
-        run: mvn -B clean verify -Pci
-
       - name: 'Setup SDKMAN'
         uses: sdkman/sdkman-action@b1f9b696c79148b66d3d3a06f7ea801820318d0f
         id: sdkman
-        if: github.event_name == 'pull_request'
+
+      - name: 'Build project'
+        run: |
+          source "$HOME/.sdkman/bin/sdkman-init.sh"
+          ./mvnw --version
+          ./mvnw -B clean verify -Pci
 
       - name: 'Test submission'
-        run: ./test_ci.sh ${{ github.event.pull_request.user.login }}
+        shell: bash
+        run: |
+          ./test_ci.sh ${{ github.event.pull_request.user.login }}
         if: github.event_name == 'pull_request'
+
+