A JFrame calling another JFrame running a Thread

Question

Hi,
here is my problem: I have an instance of Frame1 (extending JFrame) containing a button. When this button is clicked, a new instance of Frame2 (extending JFrame too) is created. The constructor of this Frame2 then calls the run method of an implementation of Runnable (called MyThread). For the purpose of this example I put a simple incrementation of a counter in the run method of the thread.
The goal is to stop the incrementation by clicking anytime on the stop button of Frame2, hence ending the thread.
When I create a new instance of Frame2, it works fine and I am able to end the thread, but when I create an instance of Frame1, the application freezes and I don't get any control on Frame2.
The code for those classes is:
public class Frame1 extends JFrame implements ActionListener{
     public static void main(String[] args) {
          new Frame1();
     public Frame1(){
          getContentPane().setLayout(new GridLayout(1,1));
          JButton b = new JButton("Run");
          b.addActionListener(this);
          getContentPane().add(b);
          setVisible(true);
          setSize(400,400);          
     public void actionPerformed(ActionEvent e) {
          Frame2 f= new Frame2();
public class Frame2 extends JFrame implements ActionListener{
     MyThread t;
     boolean running = true;
     public Frame2(){
          getContentPane().setLayout(new GridLayout(1,1));
          JButton b = new JButton("Stop");
          b.addActionListener(this);
          getContentPane().add(b);
          setVisible(true);
          setSize(200,200);          
          t = new MyThread();
          t.run();
     public void actionPerformed(ActionEvent e) {
          t.setRunning(false);
public class MyThread implements Runnable{
     boolean running = true;
     public void run(){
          int count = 0;
          while(isRunning())
               count++;
          System.out.println("Last count: "+count);
     public boolean isRunning() {
          return running;
     public void setRunning(boolean running) {
          this.running = running;
One thing I have tried is to make Frame2 implementing Runnable, but it didn't work. Any idea how to get the control on Frame2?
Thanks

Answer 1

You are calling t.run() and you really should be using t.start(). The code inside run() in MyThread is not running in a separate thread, so the call that you make to t.run() never returns.