Code Samples from the Java Developers Almanac 2000

 component.addMouseListener(new MyMouseListener());
     
 public class MyMouseListener extends MouseAdapter {
   public void mouseClicked(MouseEvent evt) {
     if ((evt.getModifiers() & 
       InputEvent.BUTTON1_MASK) != 0) {
         processLeft(evt.getPoint());
       }
       if ((evt.getModifiers() & 
         InputEvent.BUTTON2_MASK) != 0) {
           processMiddle(evt.getPoint());
       }
       if ((evt.getModifiers() & 
         InputEvent.BUTTON3_MASK) != 0) {
           processRight(evt.getPoint());
       }
   }
 }