点击面板变换面板上显示的字符

/**
 *
 */
package Lyt2;

import java.awt.BorderLayout;

import javax.swing.JFrame;

/**
 * @author Administrator
 *
 */
public class lyt extends JFrame{
 public lyt()
 {
    pressShow l=new pressShow();
    setLayout(new BorderLayout());
    add(l);
 }

 /**
  * @param args
  */
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  lyt frame=new lyt();
  frame.setTitle("change");
  frame.setSize(700,800);
  frame.setLocationRelativeTo(null);
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.setVisible(true);

}

}

 

 

/**
 *
 */
package Lyt2;

import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JPanel;
/**
 * @author Administrator
 *
 */
public class pressShow extends JPanel{
 /**
  * @param args
  */
 int i=0;
 private String message0=new String("Java is fun");
 private String message1=new String("Java is powerful");
 private String message2=new String("");
 public pressShow()
 {
  
  addMouseListener(new MouseAdapter()
  {
   public void mousePressed(MouseEvent e)
   {   i++;
    message2=message0;
    repaint();    
   }
  });
 }
 protected void paintComponent(Graphics g)
 {
  super.paintComponent(g);
  if(i%2==0)
    g.drawString(message0, 40, 40);
  else
   g.drawString(message1, 40, 40);
   
 }   
}