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54
55 package org.apache.jetspeed.portlet.event;
56
57 /**
58  ** The <CODE>MessageAdapter</CODE> is an message listener in which
59  ** all callback methods are empty implementations. The message
60  ** adapter makes it more convenient for an object to listen for
61  ** message events. In particular, by using the message adapter,
62  ** it is possible to implement only those callback methods in
63  ** which you are interested. Without the Message adapter, you must
64  ** implement all callback methods, even if the method is empty.
65  **
66  ** <P>
67  ** At this stage, this may sound like overkill since the message
68  ** listener only defines one method. The adapter therefore only
69  ** provides a default implementation for a method you are going
70  ** override anyway. But to ensure backward compatibility in future
71  ** release, it is recommended to still follow this practice so
72  ** that you will be able to enjoy functionality in future releases
73  ** without having to go back to all your listener code.
74  **
75  ** <P>
76  ** To use the message adapter, you create a subclass of
77  ** <CODE>MessageAdapter</CODE> and override the desired callback
78  ** methods. You then create an instance of the message adapter
79  ** subclass and use it to register it as a listener for message
80  ** events.
81  **
82  ** @see MessageEvent
83  **
84  ** @author <A HREF="mailto:tboehme@us.ibm.com">Thomas F. Boehme</A>
85  **/
86
87 public abstract class MessageAdapter implements MessageListener
88 {
89     public void messageReceived (MessageEvent event)
90     {
91     }
92 }
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