Mak this work on Java 17 onwards

Author: NotMyFault

.gitignore

@@ -11,3 +11,5 @@ buildNumber.properties
 
 # Avoid ignoring Maven wrapper jar file (.jar files are usually ignored)
 !/.mvn/wrapper/maven-wrapper.jar
+
+.idea

pom.xml

@@ -6,12 +6,12 @@
   <packaging>jar</packaging>
   <version>1.0-SNAPSHOT</version>
   <name>my-app</name>
-  <url>http://maven.apache.org</url>
+  <url>https://maven.apache.org</url>
   <dependencies>
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.13.2</version>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <version>5.9.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
@@ -24,7 +24,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-compiler-plugin</artifactId>
-          <version>3.8.1</version>
+          <version>3.10.1</version>
         </plugin>
       </plugins>
     </pluginManagement>
@@ -33,7 +33,7 @@
         <!-- Build an executable JAR -->
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jar-plugin</artifactId>
-        <version>3.2.0</version>
+        <version>3.3.0</version>
         <configuration>
           <archive>
             <manifest>
@@ -47,7 +47,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-enforcer-plugin</artifactId>
-        <version>3.0.0-M3</version>
+        <version>3.1.0</version>
         <executions>
           <execution>
             <id>enforce-maven</id>
@@ -57,8 +57,11 @@
             <configuration>
               <rules>
                 <requireMavenVersion>
-                  <version>[3.5.4,)</version>
+                  <version>[3.8.6,)</version>
                 </requireMavenVersion>
+                <requireJavaVersion>
+                  <version>[11,)</version>
+                </requireJavaVersion>
               </rules>
             </configuration>
           </execution>

src/main/java/com/mycompany/app/App.java

@@ -3,8 +3,7 @@
 /**
  * Hello world!
  */
-public class App
-{
+public class App {
 
     private final String message = "Hello World!";
 

src/test/java/com/mycompany/app/AppTest.java

@@ -1,11 +1,14 @@
 package com.mycompany.app;
 
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
 import java.io.ByteArrayOutputStream;
 import java.io.PrintStream;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.After;
-import static org.junit.Assert.*;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
 
 /**
  * Unit test for simple App.
@@ -15,7 +18,7 @@ public class AppTest
 
     private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
 
-    @Before
+    @BeforeEach
     public void setUpStreams() {
         System.setOut(new PrintStream(outContent));
     }
@@ -40,7 +43,7 @@ public void testAppMain()
         }
     }
 
-    @After
+    @AfterEach
     public void cleanUpStreams() {
         System.setOut(null);
     }