import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;

/**
   This program shows a clock that is updated once per second.
*/
public class TimerTest extends JApplet
{
    public JPanel panel;
    public Timer t;
    ActionListener listener;
    public TimerTest()
    {
	final int FIELD_WIDTH = 20;
	final JTextField textField = new JTextField(FIELD_WIDTH);
	panel = new JPanel();

	//Container contentPane = frame.getContentPane();
	//contentPane.setLayout(new FlowLayout());
	panel.add(textField);

	listener = new 
				  ActionListener()
	{
	    public void actionPerformed(ActionEvent event)
	    {
		Date now = new Date();
		textField.setText(now.toString());
	    }
	};
    }

    public void startAnimation()
    {
	if (t == null)
	{
	    final int DELAY = 1000; 
	 // milliseconds between timer ticks
	    Timer t = new Timer(DELAY, listener);
	    t.start();
	}
	else if (!t.isRunning()) t.restart();
    }

    public void stopAnimation()
    {
	t.stop();
    }

    
    public void init() {
	getContentPane().add(panel);
    }
    public void start() {
	startAnimation();
    }
    public void stop() {
	stopAnimation();
    }

    public static void main(String[] args)
    {
	TimerTest test = new TimerTest();
      JFrame frame = new JFrame();

      Container contentPane = frame.getContentPane();
      //contentPane.setLayout(new FlowLayout());
      contentPane.add(test.panel);

      test.startAnimation();

      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setVisible(true);
   }
}

Results