How can I restart a Java application?

Question

How can I restart a Java AWT application? I have a button to which I have attached an event handler. What code should I use to restart the application?

I want to do the same thing that Application.Restart() do in a C# application.

Answer 1

Of course it is possible to restart a Java application.

The following method shows a way to restart a Java application:

public void restartApplication() {   final String javaBin = System.getProperty("java.home") + File.separator + "bin" + File.separator + "java";   final File currentJar = new File(MyClassInTheJar.class.getProtectionDomain().getCodeSource().getLocation().toURI());    /* is it a jar file? */   if(!currentJar.getName().endsWith(".jar"))     return;    /* Build command: java -jar application.jar */   final ArrayList<String> command = new ArrayList<String>();   command.add(javaBin);   command.add("-jar");   command.add(currentJar.getPath());    final ProcessBuilder builder = new ProcessBuilder(command);   builder.start();   System.exit(0); } 

Basically it does the following:

1. Find the java executable (I used the java binary here, but that depends on your requirements)
2. Find the application (a jar in my case, using the MyClassInTheJar class to find the jar location itself)
3. Build a command to restart the jar (using the java binary in this case)
4. Execute it! (and thus terminating the current application and starting it again)

Answer 2

import java.io.File; import java.io.IOException; import java.lang.management.ManagementFactory;  public class Main {     public static void main(String[] args) throws IOException, InterruptedException {         StringBuilder cmd = new StringBuilder();         cmd.append(System.getProperty("java.home") + File.separator + "bin" + File.separator + "java ");         for (String jvmArg : ManagementFactory.getRuntimeMXBean().getInputArguments()) {             cmd.append(jvmArg + " ");         }         cmd.append("-cp ").append(ManagementFactory.getRuntimeMXBean().getClassPath()).append(" ");         cmd.append(Main.class.getName()).append(" ");         for (String arg : args) {             cmd.append(arg).append(" ");         }         Runtime.getRuntime().exec(cmd.toString());         System.exit(0);     } } 

Dedicated to all those who say it is impossible.

This program collects all information available to reconstruct the original commandline. Then, it launches it and since it is the very same command, your application starts a second time. Then we exit the original program, the child program remains running (even under Linux) and does the very same thing.

WARNING: If you run this, be aware that it never ends creating new processes, similar to a fork bomb.