Java.lang.IllegalThreadStateException - Trying to restart a Thread

Question

Hi, since I'm new to this forum, I'll start right off with a question.
I'm trying to create an application, which guides the user trough several windows. In the first window there is some user input, and frame2 opens. frame2 then opens, depending on user input, frame1 (restart the cycle) or frame3.
I tried this with Threads, a Thread for each frame to keep things less complicated (less messy etc.).
Now the problem:
When I try to restart frame1, I get the error "java.lang.IllegalThreadStateException". The source code:
public class Sss extends Thread
    (public variables that can be changed or used by other classes)
    public static frame1 a = new frame;
    public static void main(String[] args)
        a.start();
public class frame1 extends Thread implements ActionListener
    //several public static variables/object for the frame etc.      
    public frame1()
    public void run()
          //create the frame, add objects, add actionlisteners
    public void actionPerformed(ActionEvent e)
        //several buttons redirected to different methodes
    //several methodes
    public void end() //is called in a method
      frame2 p = new frame2();
       p.start();
    } This still works, but then:
public class frame2 extends Thread implements ActionListener
//several public static variables/object for the frame etc
    public frame2()
    public void run()
//create the frame, add objects, add actionlistener
      public void end()
            if(a)          //boolean a is true or false
                frame1 q = new frame1();
                q.start();
            else
                 frame3 w = new frame3();
                 w.start();
public void actionPerformed(ActionEvent e)
        //several buttons redirecting to different methods
} In the end method, "q.start();" gives the error. Am I doing something wrong? Shouldn't I be using Threads at all, should I try something different(what, how?)
I'm a student from The Netherlands, 18 years old, and I'm going to study "technische informatica" (don't know what it is in English, sorry, but it involves programming ;)). I've worked with Java on a low profile the last two years, learning & exploring, my most difficult application made is an ChatProgram (client/server based, in a local network). So this gives you my level in programming a little bit, I hope ;)
If someone is able to help me, please.
Niek

Answer 1

Niekfct wrote:
Well it's not actually helping me, you're posting things what I've already found out. And I can't imagine you've put a lot of time in such an answer. But if someone DOES post a usefull answer, i will be grateful for it. So if someone can help me, please.
And with help I mean, maybe an other way to do this, maybe a way to slightly adjust the existing classes to make it work.
(Please don't look at me as if I'm some lazy boy who can't figure anything out by himself. I'm trying to help others, and I hope others will help me.)Uhm, how are you trying to help others with this?
Also, how is pointing out that the path you are currently taking is pointless and a waste of time not helpful. At the very least it should cause you to stop even attempting to continue along that path, and prompt you to take a step back and try to look at the problem from another angle.
Jeesh, instead you just, essentially, say "Shut up! I know what I'm doing!". Well, that sounds like you really wanted help. Sounded more like you wanted confirmation, not help.
In any case, why don't you simply get rid of all references to threads, and simply change all but the main frame to JDialogs?
From what I can I see, of what you have posted here, that should be more than enough.
Just make sure, of course, that you don't mix your business logic into your GUI. Which you must have be doing currently, since a GUI class, in and of itself, has absolutely no reason to need it's own thread. It wouldn't help anything regardless of how you looked at it.