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

public class HandleAction implements ActionListener{
    JLabel JLabel1,JLabel2;
    JFrame mainJFrame;
    Container con;
    JButton loginbtn,cancelbtn;
    JTextField userText;
    JTextField passwordField;
     
public void actionPerformed(ActionEvent e){
    String msg;
    if(e.getSource()==loginbtn){
    msg="your username:"+userText.getText()+"\n your password:"
    +new String(passwordField.getText());
    JOptionPane.showMessageDialog(mainJFrame,msg);
    }
    else if(e.getSource()==cancelbtn){
        passwordField.setText("");
        userText.setText("");
    }
} 
public HandleAction(){
    JLabel1=new JLabel("用户名");
    JLabel1.setBounds(new Rectangle(20,20,60,20));//设置位置左边距、上边距、宽度、高度
    JLabel2=new JLabel("密码");
    JLabel2.setBounds(new Rectangle(20,50,60,20));//设置位置左边距、上边距、宽度、高度
    mainJFrame=new JFrame("后台登陆");
    con=mainJFrame.getContentPane();
    con.setLayout(null);//要设置成null,不然默认是BorderLayout布局
    loginbtn=new JButton("登陆");
    loginbtn.setBounds(new Rectangle(20,80,60,20));//设置位置左边距、上边距、宽度、高度
    loginbtn.addActionListener(this);
    cancelbtn=new JButton("取消");
    cancelbtn.setBounds(new Rectangle(90,80,60,20));//设置位置左边距、上边距、宽度、高度
    cancelbtn.addActionListener(this);
    userText=new JTextField();
    userText.setColumns(20);
    userText.setBounds(new Rectangle(90,20,60,20));//设置位置左边距、上边距、宽度、高度
    passwordField=new JPasswordField();
    passwordField.setColumns(20);
    passwordField.setBounds(new Rectangle(90,50,60,20));//设置位置左边距、上边距、宽度、高度
    con.add(JLabel1);
    con.add(userText);
    con.add(JLabel2);
    con.add(passwordField);
    con.add(loginbtn);
    con.add(cancelbtn);
    mainJFrame.setSize(300,300);
    mainJFrame.setVisible(true);
    mainJFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
}
public static void main(String[] args){new HandleAction();}
}