10例子8.txt

这是一本java基础教程 对新手上路有很大帮助

import java.awt.*; 
import java.awt.event.*;
import javax.swing.*;
public class Example10_8{
    public static void main(String args[ ]){
       PoliceWindow policeWin=new PoliceWindow();
    }
}
class PoliceWindow extends JFrame implements ActionListener{
    JTextField titleText;
    JPasswordField passwordText; 
    PoliceWindow(){
       titleText=new JTextField(10);
       passwordText=new JPasswordField (10);
       passwordText.setEchoChar('*');
       titleText.addActionListener(this);
       passwordText.addActionListener(this);
       setLayout(new FlowLayout());
       add(titleText); 
       add(passwordText); 
       setBounds(100,100,150,150);
       setVisible(true);
       validate();
       setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e){
       JTextField textSource=(JTextField)e.getSource(); 
       if(textSource==titleText)
           this.setTitle(titleText.getText());
       else if(textSource==passwordText){
           char c[]=passwordText.getPassword();
           titleText.setText(new String(c));
       }   
    }
}