Java编写一个简单的窗口程序

package inter.frame;import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;public class MenuTest { /**
* @param args
*/
JFrame frame;
JMenuBar mb;
JMenu m;
JMenuItem mi1;
JMenuItem mi2; public MenuTest() {
initFrame();
initAction();
} public void initFrame() {
frame = new JFrame();
mb = new JMenuBar();
m = new JMenu("学生查询");
mi1 = new JMenuItem("确认");
mi2 = new JMenuItem("取消"); m.add(mi1);
m.add(mi2);
mb.add(m);
frame.add(mb, BorderLayout.NORTH);
frame.setSize(300, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
} public void initAction() {
mi1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
System.out.println("click");
JOptionPane.showMessageDialog(null, "你点击了确定按钮");
}
});
mi2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
JOptionPane.showMessageDialog(null, "你点击了取消按钮");
}
});
} public static void main(String[] args) {
// TODO Auto-generated method stub
new MenuTest();
}}

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Test3 extends JFrame implements ActionListener{
JMenu m;
JMenuItem mi1,mi2;
JMenuBar mb;

public Test3(){
m = new JMenu("学生查询");
mi1 = new JMenuItem("确认");
mi2 = new JMenuItem("取消");
mb = new JMenuBar();
m.add(mi1);
m.add(mi2);
mb.add(m);
this.setJMenuBar(mb);
this.setSize(400,300);
this.setLocationRelativeTo(null);//窗口居中
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mi1.addActionListener(this);
mi2.addActionListener(this);
}
public static void main(String[] args){
new Test3();

}
public void actionPerformed(ActionEvent ae){
if(ae.getSource()==mi1){
JOptionPane.showMessageDialog(null, "你点击了确定按钮"); }else{
JOptionPane.showMessageDialog(null, "你点击了取消按钮"); }
}

}