javaswing做菜单栏

用eclipse开发的一个简单菜单窗口，源代码如下：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MenuTest {
public static void main(String[] args) {
MenuJFrame menu = new MenuJFrame();
menu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
menu.setVisible(true);
}
}
class MenuJFrame extends JFrame {
private final int Width = 480;
private final int Height = 640;
private Action saveAction ;
private Action saveAsAction;
public MenuJFrame(){
setSize(Width,Height);
JMenu File = new JMenu("file");
JMenuItem open = File.add(new TestAction("open"));
open.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,Input Event.CTRL_MASK));
File.addSeparator();
saveAction = new TestAction("save");
JMenuItem save = File.add(saveAction);
File.addSeparator();
saveAsAction = new TestAction("saveAs");
JMenuItem saveAs = File.add(saveAsAction);
File.addSeparator();
File.add(new AbstractAction("exit"){
public void actionPerformed(ActionEvent e) {
System.exit(0);
}});
JMenu Edit = new JMenu("Edit");
Action cut = new TestAction("cut");
cut.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));
Action copy = new TestAction("copy");
cut.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
Action paste = new TestAction("paste");
cut.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));
Edit.add(cut);
Edit.add(copy);
Edit.add(paste);
JMenu option = new JMenu("option");
final JCheckBoxMenuItem ReadOnly = new JCheckBoxMenuItem("Read-Only");
ReadOnly.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
boolean control = !(ReadOnly.isSelected());
saveAction.setEnabled(control);
saveAsAction.setEnabled(control);
}
});
ButtonGroup group = new ButtonGroup();
JRadioButtonMenuItem Insert = new JRadioButtonMenuItem("Insert");
Insert.setSelected(true);
JRadioButtonMenuItem OverType = new JRadioButtonMenuItem("OverType");
group.add(Insert);
group.add(OverType);
JMenu Option = new JMenu("Option");
Option.add(ReadOnly);
Option.addSeparator();
Option.add(Insert);
Option.add(OverType);
Edit.addSeparator();
Edit.add(Option);
JMenu Help = new JMenu("Help");
Help.setMnemonic('H');
JMenuItem Index = new JMenuItem("Index");
Index.setMnemonic('I');
Help.add(Index);
Action AboutAction = new TestAction("AboutAction");
AboutAction.putValue(Action.MNEMONIC_KEY,new Integer('A'));
Help.add(AboutAction);
JMenuBar bar = new JMenuBar();
setJMenuBar(bar);
bar.add(File);
bar.add(Edit);
bar.add(Help);
JPopupMenu popup = new JPopupMenu();
popup.add(cut);
popup.add(copy);
popup.add(paste);
JPanel panel = new JPanel();
panel.setComponentPopupMenu(popup);
add(panel);
}
}
class TestAction extends AbstractAction{
public TestAction(String name){
super(name);
}
public void actionPerformed(ActionEvent e) {
System.out.println(getValue()+" selected");
}
}。