初学java 请问 jb5 中popup menu 如何使用？？
能详细点吗？？

package untitled5;

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

public class Frame1 extends JFrame
{
  JPanel contentPane;
  JButton jButton1 = new JButton();
  JPopupMenu jPopupMenu1 = new JPopupMenu();
  JMenuItem jMenuItem1 = new JMenuItem();
  JMenuItem jMenuItem2 = new JMenuItem();

  //Construct the frame
  public Frame1()
  {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try
    {
      jbInit();
    }
    catch(Exception e)
    {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception
  {
    //setIconImage(Toolkit.getDefaultToolkit().createImage(Frame1.class.getResource("[Your Icon]")));
    contentPane = (JPanel) this.getContentPane();
    jButton1.setBounds(new Rectangle(119, 98, 79, 29));
    jButton1.setText("jButton1");
    jButton1.addActionListener(new java.awt.event.ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
        jButton1_actionPerformed(e);
      }
    });
    contentPane.setLayout(null);
    this.setSize(new Dimension(400, 300));
    this.setTitle("Frame Title");
    jMenuItem1.setText("fdg");
    jMenuItem2.setText("gggg");
    jPopupMenu1.addSeparator();
    jPopupMenu1.add(jMenuItem1);
    jPopupMenu1.add(jMenuItem2);
    contentPane.add(jButton1, null);
  }
  //Overridden so we can exit when window is closed
  protected void processWindowEvent(WindowEvent e)
  {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING)
    {
      System.exit(0);
    }
  }

  void jButton1_actionPerformed(ActionEvent e)
  {
     jPopupMenu1.show(this,90,90);
  }
}