Java 3D Desktop Environment旨在使用Java 3D来创建一个3D桌面环境。功能包括：分布式的应用程序

				package org.j3de.input;
				
				import java.util.List;
				import java.util.Vector;
				
				public class ActivationManager {
				  private List listeners;
				                          
				  public ActivationManager() {
				    listeners = new Vector();
				  }                         
				  
				  public void addActivationListener(ActivationListener listener) {
				    listeners.add(listener);
				  }                          
				  
				  public void setActivation(boolean isActive) {
				    for (int i=0; i				      ((ActivationListener)listeners.get(i)).setActivation(isActive);
				  }
				}