Problem with threads in JFrame

Question

Hy everyone...i have a small problem when i try to insert clock in my JFrame , because all i get is an empty text field.
What i do is that i create inner class that extends Thread and implements Runnable , but i dont know ... i saw some examples on the intrnet...but they are all for Applets...
Does any one know how i can implement this in JFrame (JTextField in JFrame).
Actually any material on threads in JFrame or JPanel would be great....THNX.

Answer 1

For my original bad thread version, I have rewritten it mimicking javax.swing.Timer
implementation, reducing average CPU usage to 2 - 3%.
Will you try this:
import javax.swing.*;
import java.awt.*;
import java.text.*;
import java.util.*;
public class SamurayClockW{
  JFrame frame;
  Container con;
  ClockTextFieldW ctf;
  public SamurayClockW(){
    frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    con = frame.getContentPane();
    ctf = new ClockTextFieldW();
    con.add(ctf, BorderLayout.SOUTH);
    frame.setBounds(100, 100, 300, 300);
    frame.setVisible(true);
    ctf.start();
  public static void main(String[] args){
    new SamurayClockW();
class ClockTextFieldW extends JTextField implements Runnable{
  String clock;
  boolean running;
  public ClockTextFieldW(){
    setEditable(false);
    setHorizontalAlignment(RIGHT);
  public synchronized void start(){
    running = true;
    Thread t = new Thread(this);
    t.start();
  public synchronized void stop(){
    running = false;
  public synchronized void run(){
    SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
    try{
      while (running){
        clock = sdf.format(new Date());
        SwingUtilities.invokeLater(new Runnable(){
          public void run(){
            setText(clock);
        try{
          wait(1000);
        catch (InterruptedException ie){
          ie.printStackTrace();
    catch (ThreadDeath td){
      running = false;
}