Answer: Here it is

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

   class Timer extends Thread {
      JTextField out;
      int i=0;
   
      Timer (JTextField out) { this.out = out;   }
   
      public void run() {
         while (true) {
            try { sleep(1000); }
            catch (InterruptedException e) {  }
            out.setText(String.valueOf(i++));
         }
      }
   }

   class SecTimer extends JFrame implements ActionListener {
      JTextField out;
      JButton begn, done, susp, cont;
      Timer timer=null;
   
      public SecTimer () {
         setLayout(new BorderLayout());
         add("Center", out = new JTextField());
         out.setEditable(false);
         out.setBackground(new Color(200,200,255));
         out.setFont(new Font("TimesRoman",Font.BOLD,48));
      
         JPanel p = new JPanel();
         p.setLayout(new GridLayout(1,4));
         p.add(begn = new JButton("Start"));
         p.add(done = new JButton("Stop"));
         p.add(susp = new JButton("Suspend"));
         p.add(cont = new JButton("Resume"));
         add("South", p);
            
         begn.addActionListener(this);
         done.addActionListener(this);
         susp.addActionListener(this);
         cont.addActionListener(this);
      }
            
      public void actionPerformed (ActionEvent event) {
         if (event.getSource() == begn) {
            timer = new Timer(out);
            timer.start();
         } else if (event.getSource() == done) {
            if (timer != null) timer.stop();
            timer = null;
         } else if (event.getSource() == susp) {
            if (timer != null) timer.suspend();
         } else if (event.getSource() == cont) {
            if (timer != null) timer.resume();
         }
      }
   }

   public class SecondTimer {
      public static void main (String arg[]) {
         SecTimer timer = new SecTimer();
         timer.setSize(400,100);
         timer.setVisible(true);
      }
  }