窗口程序

package 窗口;import java.awt.MenuBar;import java.awt.event.InputEvent;import java.awt.event.KeyEvent;import javax.swing.JFrame;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.KeyStroke;public class 作业练习 {public static void main(String[] args) {// TODO Auto-generated method stubMyWindow win = new MyWindow("浏览器");}}class MyWindow extends JFrame{JMenuBar menubar;JMenu menu1,menu2,menu3,menu4;JMenuItem item1,item2,item3,item4,item5,item6,item7;MyWindow(String s){super(s);setTitle(s);setSize(400,300);setLocation(120,120);setVisible(true);menubar = new JMenuBar();menu1 = new JMenu("文件");menu2 = new JMenu("编辑");menu3 = new JMenu("查看");item3=new JMenuItem("打开x");item4=new JMenuItem("打开y");item5=new JMenuItem("复制");item6=new JMenuItem("停止");item7=new JMenuItem("刷新");menu3.add(item6);menu3.add(item7);menu2.add(item5);menu4 = new JMenu("打开");menu4.add(item3);menu4.add(item4);item2 = new JMenuItem("保存");menu1.add(menu4);menu1.add(item2);menubar.add(menu1);menubar.add(menu2);menubar.add(menu3);        setJMenuBar(menubar);        validate();}}