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.events;
				
				public class UnknownEventException extends Exception {
				  public UnknownEventException(String s) {
				    super("Unknown class for Event : " + s);
				  }
				}