Trying build on JDK 12.

.github/workflows/checkstyle.yml

@@ -22,10 +22,10 @@ jobs:
     # Grab the newest version of repo
     - uses: actions/checkout@v2
     # Set JDK to 11
-    - name: Set up JDK 11
+    - name: Set up JDK 12
       uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 12
     # Building with MVN
     - name: Build with Maven
       run: mvn -B clean compile install package --file pom.xml

.github/workflows/maven-publish.yml

@@ -14,10 +14,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 11
+    - name: Set up JDK 12
       uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 12
         server-id: github # Value of the distributionManagement/repository/id field of the pom.xml
         settings-path: ${{ github.workspace }} # location for the settings.xml file
 

.github/workflows/maven.yml

@@ -16,9 +16,9 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 11
+    - name: Set up JDK 12
       uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 12
     - name: Build with Maven
       run: mvn -B package --file pom.xml

.github/workflows/surefire-reports.yml

@@ -23,7 +23,7 @@ jobs:
       - uses: actions/setup-java@v2
         with:
           distribution: 'adopt' # See 'Supported distributions' for available options
-          java-version: '11'  
+          java-version: '12'
       - name: Run Tests
         run: mvn test --batch-mode --fail-at-end
       - name: Publish Test Report

Dockerfile

@@ -10,7 +10,7 @@ RUN mvn dependency:go-offline -B
 # RUN mvn package
 RUN mvn clean install package
 
-FROM openjdk:11-jre-slim-bullseye
+FROM adoptopenjdk/openjdk12-openj9:latest
 # Add the service itself
 COPY --from=maven  target/hell-on-world-rest-*.jar /usr/share/javalin/
 

README.md

@@ -8,7 +8,7 @@ Represents dockerized Javalin REST microsevice with GET example in.
 https://javalin.io/tutorials/docker
 
 # Parts:
-- JDK 11
+- JDK 12
 - Javalin
 - Docker
 

pom.xml

@@ -12,8 +12,8 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>12</maven.compiler.source>
+        <maven.compiler.target>12</maven.compiler.target>
         <maven.compiler.plugin>2.4</maven.compiler.plugin>
         <maven.shade.plugin>3.1.0</maven.shade.plugin>
         <dockerfile.maven.plugin>1.2.2</dockerfile.maven.plugin>

workflows/maven.yaml

@@ -8,10 +8,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.12
         uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 12
       - name: Build with Maven
         run: mvn --batch-mode --update-snapshots verify