Java run command in ALREADY RUNNING CMD window

I am creating a little program to take away some of my work by using a GUI. What I have right now is a little program with a button "Start" which starts a CMD-based application. What I need to do is enter a certain command in that开发者_StackOverflow CMD window. I want to add a button which fills out this command for me.

Is this even possible?

P.S.: CMD is Windows's Command Prompt.

Thank you all.

This works if it is an external command:

String command = "cmd";   //Replace with your command
Runtime.getRuntime().exec(command);

If it is an internal command then that will not work, but there is a workaround: create a batch file with the commands in it, and put a String with the path to the batch file as an argument.

Runtime.getRuntime().exec("Temp.bat");

Or you can write the batch file programmatically using this method:

private void batch(String commands){
  try{
    String filename = "Temp.bat";
    File f = new File(filename);
    PrintWriter writer = new PrintWriter(f);
    writer.print(commands);
    writer.close();
    Runtime.getRuntime().exec(filename);

    long x = getTime + 3000;
    do{
      //Wait
    }while(getTime < x);

    f.delete();
  }catch(Exception ex){
    ex.printStackTrace();
  }
}

private long getTime(){
  SimpleDateFormat datef = new SimpleDateFormat("yyyyDDDHHmmssSSS");
  Date date = new Date();
  return Long.parseLong("" + datef.format(date));
}

It depends on how your CMD-based application receives its input.

If it receives input from the input stream of the CMD window, this article explains how to get a reference to the input stream and send messages to it: Java exec - execute system processes with Java ProcessBuilder and Process.

If your CMD window is running a command that doesn't take input, and you want to execute another command, then I think you would have to run your second command in a separate CMD process.