Thread: Swing & Threading ... Systen hangs

Consider the code below ...


public class frmMain extends javax.swing.JFrame {


Boolean running;


public class MyThread extends Thread
{
public frmMain owner;
public int value = 0;

public void run()
{

value = 0;

while (value < 200000)
{
if (running == false) break;

owner.setTitle(String.valueOf(value));


value++;

}



}
}


/**
* Creates new form frmMain
*/
public frmMain() {
initComponents();
}



private void btnStartActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:

running = true;

MyThread j = new MyThread();
j.owner = this;
j.start();


}

private void btnStopActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:


running = false;


}

-----------------------------------

Basically I have a long process in my Swing code. Within that process I want to make sure my jFrame & graphics is constantly being updated & refreshed. My process is in a background thread, but I need a way to ensure that the thread is detached from the jFrame and that the jFrame can display what is happening in the process.

This is a threading issue I believe.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
/** Resolve the unresponsive UI problem by running the compute-intensive task
    in this own thread, which yields control to the EDT regularly */
public class UnresponsiveUIwThreadSleep extends JFrame {
   private boolean stop = false;
   private JTextField tfCount;
   private int count = 1;
 
   /** Constructor to setup the GUI components */
   public UnresponsiveUIwThreadSleep() {
      Container cp = getContentPane();
      cp.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 10));
      cp.add(new JLabel("Counter"));
      tfCount = new JTextField(count + "", 10);
      tfCount.setEditable(false);
      cp.add(tfCount);
 
      JButton btnStart = new JButton("Start Counting");
      cp.add(btnStart);
      btnStart.addActionListener(new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent evt) {
            stop = false;
            // Create a new Thread to do the counting
            Thread t = new Thread() {
               @Override
               public void run() {  // override the run() for the running behaviors
                  for (int i = 0; i < 100000; i++) {
                     if (stop) break;
                     tfCount.setText(count + "");
                     count++;
                     // Suspend this thread via sleep() and yield control to other threads.
                     // Also provide the necessary delay.
                     try {
                        sleep(10);  // milliseconds
                     } catch (InterruptedException ex) {}
                  }
               }
            };
            t.start();  // call back run()
         }
      });
 
      JButton btnStop = new JButton("Stop Counting");
      cp.add(btnStop);
      btnStop.addActionListener(new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent evt) {
            stop = true;
         }
      });
 
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setTitle("Counter");
      setSize(300, 120);
      setVisible(true);
   }
 
   /** The entry main method */
   public static void main(String[] args) {
      // Run GUI codes in Event-Dispatching thread for thread safety
      javax.swing.SwingUtilities.invokeLater(new Runnable() {
         @Override
         public void run() {
            new UnresponsiveUIwThreadSleep();  // Let the constructor do the job
         }
      });
   }
}

that code was an example of how to handle threads in Swing such that ur GUI doesn't become unresponsive.
Do not create swing gui in main thread.
Do not make a function call do a lot of work on button click event.Instead spawn a new thread so that ur EDT is responsive and gui refreshes