menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_D,ActionEvent.ALT_MASK));

是当鼠标焦点在你所在的程序界面上，你按下ALT和D键就能打开相应的menuItem，而menuItem.setMnemonic(KeyEvent.VK_D)则是当你把焦点放在相应的menuItem上同时按下D键显示相应的menuItem

JMenuItem mntmExchange = new JMenuItem("Exchange");

//MenuShortcut shortcut=new MenuShortcut(KeyEvent.VK_Q);

mntmExchange.setMnemonic(KeyEvent.VK_Q);

mntmExchange.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_D,ActionEvent.ALT_MASK));

ava为菜单栏添加快捷键

package swimg;

import java.awt.BorderLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

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 JMenuDemo extends JMenuBar implements ActionListener{

JMenuItem item1;

public JMenuDemo(){

add(createJMenuone());

}

public JMenu createJMenuone(){

JMenu menu=new JMenu("文件(F)");

menu.setMnemonic(KeyEvent.VK_F);

JMenuItem item=new JMenuItem("新建(N)",KeyEvent.VK_N);

item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N,ActionEvent.CTRL_MASK));

menu.add(item);

item1=new JMenuItem("退出(X)",KeyEvent.VK_X);

item1.addActionListener((ActionListener) this);

item1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,ActionEvent.CTRL_MASK));

menu.add(item1);

return menu;

}

public static void main(String[] args) {

JFrame frame=new JFrame("菜单栏");

frame.setBounds(200,200,400,400);

frame.setResizable(true);

frame.setJMenuBar(new JMenuDemo());

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setVisible(true);

}

public void actionPerformed(ActionEvent e) {

// TODO 自动生成方法存根

if(e.getSource()==item1){

System.exit(0);

}

}

}