在JAVA中如何判断鼠标的按键？

Question

import javax.swing.*;
import java.awt.event.*;public class TestMouse extends JFrame
{
TestMouse()
{
setTitle("Mouse Capture");
setBounds(200,200,400,300);
addMouseListener(new MouseHandler());
}

private class MouseHandler extends MouseAdapter
{
public void mouseClicked(MouseEvent mevent)
{
if(mevent.getButton()==MouseEvent.BUTTON1)
{
JOptionPane.showMessageDialog(null, "单击了鼠标左键！", "鼠标事件", JOptionPane.INFORMATION_MESSAGE); 
}
else if(mevent.getButton()==MouseEvent.BUTTON2)
{
JOptionPane.showMessageDialog(null, "单击了鼠标滑轮！", "鼠标事件", JOptionPane.INFORMATION_MESSAGE); 
}
else if(mevent.getButton()==MouseEvent.BUTTON3)
{
JOptionPane.showMessageDialog(null, "单击了鼠标右键！", "鼠标事件", JOptionPane.INFORMATION_MESSAGE); 
}
}
}

public static void main(String[] args)
{
TestMouse tm=new TestMouse();
tm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
tm.setVisible(true);
}
}