e9_5.java

java 初学者学习实例

import java.awt.event.*;
import java.awt.*;
import java.util.Date;
class E9_5 extends Frame implements Runnable,ActionListener
{ Thread thread=null; TextArea text=null;
   Button b_start=new Button("Start"),b_stop=new Button("Stop");
   E9_5()
    {thread=new Thread(this);
     text=new TextArea();add(text,"Center");
     Panel p=new Panel();p.add(b_start);p.add(b_stop);
     b_start.addActionListener(this) ;
     b_stop.addActionListener(this)  ;
     add(p,"North");setVisible(true);
     setSize(500,500);pack();setSize(500,500);
     setResizable ( false);                         
      addWindowListener(new WindowAdapter()
           {public void windowClosing (WindowEvent e)
              {System.exit(0);
              }
          });
   }
public void actionPerformed(ActionEvent e)
{ if(e.getSource()==b_start)
  {try {thread.start();}
      catch(Exception e1)
      {text.setText ( "在线程结束之前不赞成让线程再次调用start方法");
      }
  }
  else if(e.getSource() == b_stop)
 
      
           {thread.interrupt();}
 }
 public void run()
 {  while(true)
       {text.append("\n"+new Date());
           try{thread.sleep (1000);}
           catch(InterruptedException ee)
           {text.setText("我被消灭")  ;return; 
           }
       }
 }
 public static void main (String args[])
 {Example tt=new Example ();
 }
}