import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;

class PopupMenuTest extends JPanel
{
    static JFrame frame1;
    JLabel l1;
    JPopupMenu  popupMenu;
    
    public PopupMenuTest()
    {
        l1=new JLabel("单击鼠标右键");
        popupMenu=new JPopupMenu();
        JMenuItem menu1=new JMenuItem("橘子");
        JMenuItem menu2=new JMenuItem("菠萝");
        JMenuItem menu3=new JMenuItem("芒果");
        
        menu1.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                l1.setText("橘子");
            }
        });

        menu2.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                l1.setText("菠萝");
            }
        });
        
        menu3.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                l1.setText("芒果");
            }
        });
        
        popupMenu.add(menu1);
        popupMenu.add(menu2);
        popupMenu.add(menu3);
        
        addMouseListener(new MouseAdapter(){
            public void mouseReleased(MouseEvent e)
            {
                if(e.isPopupTrigger())
                {
                    popupMenu.show(e.getComponent(),e.getX(),e.getY());
                }
            }
        });
        
        add(l1);

    }
    
    public static void main(String [] args)
    {
        frame1=new JFrame("弹出菜单测试");
        PopupMenuTest p1=new PopupMenuTest();
        frame1.getContentPane().add("Center",p1);
        frame1.getContentPane().setBackground(Color.gray);
        frame1.setSize(200,200);
        frame1.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
        
        frame1.show();
    }
    
}

这段代码中哪段代码具有实现单击鼠标右键弹出菜单的功能啊

JDK帮助？？？ 我这只有个 API中文版  

可不可以直接告诉我啊  

我已经找了好多资料了

都没有查到才决定到论坛上问问的！