Java tutorial (#160)

* update java tutorial

* update java version:jdk 16

* update jdk version

* fixed jdk

* fixed using google formater

* fixed gradle build

Author: realDuYuanChao

.github/workflows/checkstyle.yml

@@ -8,12 +8,12 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
-      - name: Set up JDK 12
+      - name: Set up JDK 16
         uses: actions/setup-java@v1
         with:
-          java-version: 12
-      - run: wget https://github.com/google/google-java-format/releases/download/google-java-format-1.9/google-java-format-1.9-all-deps.jar -O formatter.jar
-      - run: java -jar formatter.jar --replace --set-exit-if-changed $(find . -type f -name "*.java" | grep ".*/src/.*java")
+          java-version: 16
+      - run: wget https://github.com/google/google-java-format/releases/download/v1.11.0/google-java-format-1.11.0-all-deps.jar -O formatter.jar
+      - run: java --add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED -jar formatter.jar --replace --set-exit-if-changed $(find . -type f -name "*.java" | grep ".*/src/.*java")
       - name: Commit Format changes
         if: failure()
         run: |

.github/workflows/gradle.yml

@@ -12,10 +12,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 12
+    - name: Set up JDK 14
       uses: actions/setup-java@v1
       with:
-        java-version: 12
+        java-version: 14
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Build with Gradle

.github/workflows/maven.yml

@@ -12,9 +12,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 12
+      - name: Set up JDK 16
         uses: actions/setup-java@v1
         with:
-          java-version: 12
+          java-version: 16
       - name: Build with Maven
         run: mvn clean test

.lgtm.yml

@@ -8,8 +8,8 @@
     <artifactId>untitled</artifactId>
     <version>1.0-SNAPSHOT</version>
     <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>16</maven.compiler.source>
+        <maven.compiler.target>16</maven.compiler.target>
     </properties>
     <dependencies>
         <dependency>
@@ -30,8 +30,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>9</source>
-                    <target>9</target>
+                    <source>16</source>
+                    <target>16</target>
                 </configuration>
             </plugin>
         </plugins>