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.exception;
				
				import org.j3de.permission.ExceptionHandlerPermission;
				
				public abstract class ExceptionHandler {
				  public static boolean SHOW_WARNING = true;
				  public static boolean HIDE_WARNING = false;
				  private static ExceptionHandler exceptionHandler = null;
				
				  public ExceptionHandler() {
				    SecurityManager sm = System.getSecurityManager();
				    if (sm != null) {
				       sm.checkPermission(new ExceptionHandlerPermission("instantiate"));
				    }
				
				    exceptionHandler = this;
				  }
				
				  protected abstract void handleExceptionImpl(Exception e);
				
				  public static void handleException(Exception e) {
				    if (exceptionHandler == null)
				      exceptionHandler = new DefaultExceptionHandler();
				
				    exceptionHandler.handleExceptionImpl(e);
				  }
				
				  protected abstract void handleFatalExceptionImpl(Exception e);
				
				  public static void handleFatalException(Exception e) {
				    if (exceptionHandler == null)
				      exceptionHandler = new DefaultExceptionHandler();
				
				    exceptionHandler.handleFatalExceptionImpl(e);
				  }      
				  
				  protected abstract void handleWarningImpl(String msg);
				
				  public static void handleWarning(String msg) {
				    if (exceptionHandler == null)
				      exceptionHandler = new DefaultExceptionHandler();
				
				    exceptionHandler.handleWarningImpl(msg);    
				  }
				
				}