import java.awt.*;
import java.awt.event.*;

import javax.swing.JOptionPane;

class Welcome extends Frame implements ActionListener {
    Welcome(String s) {
        setBounds(100, 100, 200, 150);
        setVisible(true);
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }

        });
    }

    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub

    }
}

class MyWindow extends Frame implements ActionListener {
    Label L1, L2;
    TextField t1, t2;
    Button b1, b2;
    MenuBar menubar;
    Menu menu;

    MyWindow(String s) {
        // 窗口设置
        super(s);
        setTitle(s);
        setLayout(new FlowLayout());
        setBounds(100, 100, 200, 150);
        setVisible(true);
        setResizable(true);
        // 添加组件
        menubar = new MenuBar();
        menu = new Menu("黄海波1040610109");
        menubar.add(menu);
        setMenuBar(menubar);
        L1 = new Label("输入用户名");
        L2 = new Label("输入密码");
        t1 = new TextField(10);
        t2 = new TextField(10);
        t2.setEchoChar('*');
        Button b1 = new Button("OK");
        Button b2 = new Button("Exit");
        add(L1);
        add(t1);
        add(L2);
        add(t2);
        add(b1);
        add(b2);
        b1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String user = t1.getText();
                String password = t2.getText();
                if (user.equals("huanghaibo") && password.equals("123456")) {
                    Welcome welcome = new Welcome("Welcome " + user);
                    closeLoginFrame();
                    //this.setVisible(false);/*这里想在Welcome弹出后将MyWindow隐藏，可是报错。*/
                } else {
                    JOptionPane.showMessageDialog(null, "用户名或密码错误");
                }

            }

        });
        b2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(1);
            }
        });
        validate();
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }

        });
    }

    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub

    }
    
    private void closeLoginFrame()
    {
        this.setVisible(false);
        //建议你用下面这个方法比较好
        //this.dispose();
    }

}

public class j411040610109  {
    public static void main(String[] args) {
        MyWindow win = new MyWindow("登陆");
    }
}