如何让java程序最小化至系统托盘

import java.awt.*;
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import javax.imageio.ImageIO;

public class Test extends JFrame{
private TrayIcon trayIcon;//托盘图标
private SystemTray systemTray;//系统托盘

public Test()
{
super("系统托盘图标");
systemTray = SystemTray.getSystemTray();//获得系统托盘的实例
setSize(150,150);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
try {
trayIcon = new TrayIcon(ImageIO.read(new File("0.gif")));
systemTray.add(trayIcon);//设置托盘的图标，0.gif与该类文件同一目录
}
catch (IOException e1) {e1.printStackTrace();}
catch (AWTException e2) {e2.printStackTrace();}

this.addWindowListener(
new WindowAdapter(){
public void windowIconified(WindowEvent e){
dispose();//窗口最小化时dispose该窗口
}
});

trayIcon.addMouseListener(
new MouseAdapter(){
public void mouseClicked(MouseEvent e){
if(e.getClickCount() == 2)//双击托盘窗口再现
setExtendedState(Frame.NORMAL);
setVisible(true);
}
});
}

public static void main(String args[])
{
new Test();
}
}

package awt;

import java.awt.AWTException;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.TrayIcon;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.ImageIcon;
import javax.swing.JFrame;

public class TrayDemo extends JFrame {

private TrayIcon trayIcon = null; // 托盘图标

private SystemTray tray = null; // 本操作系统托盘的实例

public static TrayDemo trayDemo = new TrayDemo();

private TrayDemo() {
init();
}

public void init() {
if (SystemTray.isSupported()) { // 如果操作系统支持托盘
this.tray();
}
this.setSize(300, 200);
this.setResizable(false);
// 窗口关闭时触发事件
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}

public void windowIconified(WindowEvent e) {
try {
tray.add(trayIcon); // 将托盘图标添加到系统的托盘实例中
//setVisible(false); // 使窗口不可视
dispose();
} catch (AWTException ex) {
ex.printStackTrace();
}
}
});

}

private void tray() {

tray = SystemTray.getSystemTray(); // 获得本操作系统托盘的实例
ImageIcon icon = new ImageIcon("images/30.gif"); // 将要显示到托盘中的图标

PopupMenu pop = new PopupMenu(); // 构造一个右键弹出式菜单
MenuItem show = new MenuItem("打开程序(s)");
MenuItem exit = new MenuItem("退出程序(x)");
pop.add(show);
pop.add(exit);
trayIcon = new TrayIcon(icon.getImage(), "车辆管理系统", pop);

/**
* 添加鼠标监听器，当鼠标在托盘图标上双击时，默认显示窗口
*/
trayIcon.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 2) { // 鼠标双击
tray.remove(trayIcon); // 从系统的托盘实例中移除托盘图标
setExtendedState(JFrame.NORMAL);
setVisible(true); // 显示窗口
toFront();
}
}
});
show.addActionListener(new ActionListener() { // 点击“显示窗口”菜单后将窗口显示出来
public void actionPerformed(ActionEvent e) {
tray.remove(trayIcon); // 从系统的托盘实例中移除托盘图标
setExtendedState(JFrame.NORMAL);
setVisible(true); // 显示窗口
toFront();
}
});
exit.addActionListener(new ActionListener() { // 点击“退出演示”菜单后退出程序
public void actionPerformed(ActionEvent e) {
System.exit(0); // 退出程序
}
});

}

/**
* 显示信息
*/
// 返回单一的实例对象
public static TrayDemo getInstanceTrayDemo() {
return trayDemo;
}

// 处理窗口事件

}