java源代码 请看看啊 提点宝贵的意见

				/*				 * @(#)Observer.java	1.18 03/01/23				 *				 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.				 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.				 */				package java.util;								/**				 * A class can implement the Observer interface when it				 * wants to be informed of changes in observable objects.				 *				 * @author  Chris Warth				 * @version 1.18, 01/23/03				 * @see     java.util.Observable				 * @since   JDK1.0				 */				public interface Observer {				    /**				     * This method is called whenever the observed object is changed. An				     * application calls an Observable object's				     * notifyObservers method to have all the object's				     * observers notified of the change.				     *				     * @param   o     the observable object.				     * @param   arg   an argument passed to the notifyObservers				     *                 method.				     */				    void update(Observable o, Object arg);				}