java實現用戶登錄

//用戶登錄的代碼：

//LoginFrame.java

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

 

class MyJPanel extends JPanel implements ActionListener{

       private int count=0;       

       private JLabel label1,label2;

       private JTextField text;

       private JPasswordField pass;

       private JButton button1,button2;   

       MyJPanel(){

              label1=new JLabel("用戶名");

              label2=new JLabel("密碼");

              button1=new JButton("確定");

              button2=new JButton("取消");

              text=new JTextField(20);

              pass=new JPasswordField(20);

              button1.setMnemonic(KeyEvent.VK_O);//設置按鈕快捷鍵

              button2.setMnemonic(KeyEvent.VK_C);

              button1.setActionCommand("entry");

              button2.setActionCommand("cancel");

              button1.addActionListener(this);//註冊按鈕事件

              button2.addActionListener(this);//註冊按鈕事件

              setBackground(Color.cyan);//設定面板背景色

              add(label1);

              add(text);

              add(label2);

              add(pass);

              add(button1);

              add(button2);

       }

       

       public void actionPerformed(ActionEvent e){

              if (e.getActionCommand().equals("entry")){

                     count++;  //計數

                     String username,password;

                     if (count<3) {

                            username=text.getText();

                            password=pass.getText();

                            if (username.equals("abcd")&&password.equals("123456")){

                                   text.setText("用戶名及密碼正確!");

                                   pass.setText("");                          

                            }

                            else{

                                   text.setText("");

                                   pass.setText("");                          

                            }

                     

                     }

                     else

                            System.exit(0);//退出程序

              }

              else 

                     System.exit(0);//退出程序

       }

}

 

public class  LoginFrame extends JFrame {

       public static void main(String[] args) {

              MyJPanel jp=new MyJPanel();//定義面板

              jp.setBorder(BorderFactory.createTitledBorder("輸入用戶名和密碼"));//設定邊界

              JFrame frame=new JFrame("用戶登錄");

              frame.setSize(300,150);

              frame.setContentPane(jp);//在框架中加載面板

              frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//設置框架關閉按鈕事件

              frame.setVisible(true);

       }

}