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

class  ExamThreadA1  extends  JFrame  implements  ActionListener{
    Thread    thr;
    JButton  jbstart,  jbend;
    ExamThreadA2  eta2;

    public static void main(String args[]) {
        ExamThreadA1  eta1  =  new  ExamThreadA1();
        eta1.addWindowListener(  new WindowAdapter()  {
              public  void  windowClosing(WindowEvent  we )  {
                  System.exit(0);
              }
        });
        eta1.setBounds(30,30, 400,100);
        eta1.setVisible(true);
    }
    ExamThreadA1()  {
        super("Thread Sample A");
        jbstart  =  new  JButton("START");
        jbstart.addActionListener( this);

        jbend    =  new  JButton("STOP");
        jbend.addActionListener(this);

        JPanel   jp       =  new  JPanel(new  GridLayout(2,1));
        jp.add(jbstart);
        jp.add(jbend);
        getContentPane().add(jp, BorderLayout.WEST);

        eta2  =  new  ExamThreadA2();   
        getContentPane().add(eta2, BorderLayout.CENTER);
 
        thr  =  new  Thread(eta2);
    }
    public  void  actionPerformed(ActionEvent  ae)  {
        if(ae.getSource()   ==  jbstart)  {
                thr.start();
        }  else if  (ae.getSource()   ==  jbend)   {
                eta2.end();                                        // Don't  use  stop() method
        }
    } 
}

class  ExamThreadA2  extends  JLabel implements  Runnable  {
    private  int  i;                                              

    public  void  run()  {
        while(i != 9)  {
            Date  date  =  new  Date();
            setText(date.toString());
        }
    }
    public  void  end()  {
           i  =  9;
    }
}