Minecraft custom name laucher

Question

I'm trying to create a custom name laucher for Minecraft. I run an offline server and was wanting to give some of my friends a laucher to use so they can play. I have done this before with a batch file. Now I'm using JavaUI and I'm trying to start Minecraft from the Java program. I have yet to get Minecraft to pop up.

Here is the code i am using:

if (e.getSource() == app.startNorm){
    List<String> command = new ArrayList<String>();
    command.add("java");
    command.add("-jar");
    command.add(System.getenv("APPDATA") + "\\.minecraft\\bin\\* -Djava.library.path=\"" + System.getenv("APPDATA") + "\\.minecraft\\bin\\natives\" net.minecraft.client.Minecraft CustomNameHere");
    try{
        //line below wont work
        ProcessBuilder builder = new ProcessBuilder(command);
        Process proc = builder.start();
        app.setSize(500, 300);
        app.process.setVisible(true);
        app.memory.setVisible(false);
        app.start.setVisible(false);
        InputStream in = proc.getInputStream();
    } catch (IOException e1) {
        //always get dialog, when not never see minecraft pop up
        JOptionPane.showMessageDialog(null, "There was a problem with starting Minecraft");
    }
}

I was hoping someone could show me how to get this, or any other way to lauch Minecraft from inside my program.

Answer 1

I made something similar in the past, here is the code i used:

Runtime rt = Runtime.getRuntime();                      
rt.exec("cmd /c java -jar filename.jar");

or

rt.exec("cmd /c filename.exe");