Test against Java 11

.github/workflows/build.yml

@@ -0,0 +1,44 @@
+# This workflow will build a Java project with Gradle
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
+
+name: build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ '8', '11' ]
+    name: Java ${{ matrix.Java }} build
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK
+        uses: actions/setup-java@v2
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: adopt
+      - name: Cache Gradle packages
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - name: Validate Gradle wrapper
+        uses: gradle/wrapper-validation-action@v1
+      - name: Build with Gradle
+        run: ./gradlew build
+      - name: Cleanup Gradle Cache
+        # Remove some files from the Gradle cache, so they aren't cached by GitHub Actions.
+        # Restoring these files from a GitHub Actions cache might cause problems for future builds.
+        run: |
+          rm -f ~/.gradle/caches/modules-2/modules-2.lock
+          rm -f ~/.gradle/caches/modules-2/gc.properties

build.gradle

@@ -23,9 +23,13 @@ plugins {
 }
 
 ext {
+	javaApi = "https://docs.oracle.com/javase/8/docs/api/"
+	if (JavaVersion.current() >= JavaVersion.VERSION_11) {
+		javaApi = "https://docs.oracle.com/en/java/javase/11/docs/api"
+	}
 	javadocLinks = [
-		"https://docs.oracle.com/javase/8/docs/api/",
-		"https://docs.spring.io/spring/docs/${springFrameworkVersion}/javadoc-api/"
+		javaApi,
+		"https://docs.spring.io/spring-framework/docs/${springFrameworkVersion}/javadoc-api/"
 	] as String[]
 }
 
@@ -199,7 +203,7 @@ configure(staticAnalysisProjects) {
 	apply plugin: "jacoco"
 
 	checkstyle {
-		configFile = file("${project.rootDir}/src/checkstyle/checkstyle.xml")
+		configDirectory = rootProject.file("src/checkstyle")
 		toolVersion = "${checkstyleVersion}"
 		showViolations = true
 	}

src/checkstyle/checkstyle.xml

@@ -21,12 +21,12 @@
 
 	<!-- Suppressions -->
 	<module name="SuppressionFilter">
-		<property name="file" value="src/checkstyle/checkstyle-suppressions.xml"/>
+		<property name="file" value="${config_loc}/checkstyle-suppressions.xml"/>
 	</module>
 
 	<!-- License Header -->
 	<module name="Header">
-		<property name="headerFile" value="src/checkstyle/license.header"/>
+		<property name="headerFile" value="${config_loc}/license.header"/>
 		<property name="ignoreLines" value="2, 8"/>
 	</module>