dataeventobserver.java

自己写的一个聊天的小程序 请多多指教

/*
 * Copyright (c) 2003 - 2007, Silvio Meier and Tobias Reinhard
 *
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met:
 *
 *   o Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer.
 *   o Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution.
 *   o The names of its contributors may not be used to endorse 
 *     or promote products derived from this software without 
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.sf.cscc;

/**
 * This interface has to be implemented by observers which want
 * to be notified about new data events in the event queue. Implementing 
 * this interface causes only the notification, without the delivery 
 * of the data event itself. If the corresponding {@link net.sf.cscc.DataEvent} 
 * object should be delivered with the notification, then use the 
 * interface {@link net.sf.cscc.DataEventReceivingObserver}.
 *
 *	@author			Silvio Meier (SM)
 *	@copyright      Silvio Meier, Tobias Reinhard, 2003
 *	@history		2003-05-09 SM First Version
 *                              2003-05-14 SM working on additional methods and events,
 *                              correction of some comments.
 *	@version		$Date: 2007/07/01 17:04:05 $, $Author: reode_orm $, $Revision: 1.1 $
 *	@responsibilities	Provides an interface for an data event observer call.
 *	@invariant		-
 *	@obligation		-
 */
public interface DataEventObserver extends DataEventBaseObserver {
    /**
     *   This interface method is called by objects the {@link net.sf.cscc.DataEventObservable}
     *   class. The implenting class has to register at the specific 
     *   object of the class {@link net.sf.cscc.DataEventObservable} to get notifications
     *   about new data events in the event queue. This is done
     *   by calling the method {@link net.sf.cscc.ServerConnectionManager#addObserver(DataEventBaseObserver o)}
     *   for observing the incoming event queue of the server respectively the method
     *   {@link net.sf.cscc.ClientConnectionManager#addObserver(DataEventBaseObserver o)} for
     *   the incoming event queue of the client.
     *   The implementing class has to get the specific data event by calling the method
     *   {@link net.sf.cscc.ServerConnectionManager#getDataEvent()} for incoming
     *   data event queue of the server, respectively {@link net.sf.cscc.ClientConnectionManager#getDataEvent()}
     *   for the incoming data event queue of the client. After getting the events, the observer
     *   has to take care of the data event removal from the incoming queue by calling
     *   the methods {@link net.sf.cscc.ServerConnectionManager#removeDataEvent()}.<br>
     *   Additional information can also be found at the interface method
     *   {@link net.sf.cscc.DataEventReceivingObserver#receiveEvent(DataEvent de)}.
     *
     *   @pre true
     *   @post true
     *   @obligation The removal of the data event from the incoming event 
     *               queue has to be done by the observer!
     *   @see net.sf.cscc.DataEventReceivingObserver#receiveEvent(DataEvent de)
     */
    void receiveEvent();
}