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1   /***
2    * Redistribution and use of this software and associated documentation
3    * ("Software"), with or without modification, are permitted provided
4    * that the following conditions are met:
5    *
6    * 1. Redistributions of source code must retain copyright
7    *    statements and notices.  Redistributions must also contain a
8    *    copy of this document.
9    *
10   * 2. Redistributions in binary form must reproduce the
11   *    above copyright notice, this list of conditions and the
12   *    following disclaimer in the documentation and/or other
13   *    materials provided with the distribution.
14   *
15   * 3. The name "Exolab" must not be used to endorse or promote
16   *    products derived from this Software without prior written
17   *    permission of Exoffice Technologies.  For written permission,
18   *    please contact info@exolab.org.
19   *
20   * 4. Products derived from this Software may not be called "Exolab"
21   *    nor may "Exolab" appear in their names without prior written
22   *    permission of Exoffice Technologies. Exolab is a registered
23   *    trademark of Exoffice Technologies.
24   *
25   * 5. Due credit should be given to the Exolab Project
26   *    (http://www.exolab.org/).
27   *
28   * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
32   * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39   * OF THE POSSIBILITY OF SUCH DAMAGE.
40   *
41   * Copyright 2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   * $Id: CachedMessageRef.java,v 1.3 2005/12/20 20:31:59 tanderson Exp $
44   */
45  package org.exolab.jms.messagemgr;
46  
47  import javax.jms.JMSException;
48  
49  import org.exolab.jms.message.MessageImpl;
50  
51  
52  /***
53   * An {@link MessageRef} which references messages located in an {@link
54   * MessageCache}.
55   *
56   * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
57   * @version $Revision: 1.3 $ $Date: 2005/12/20 20:31:59 $
58   */
59  class CachedMessageRef extends AbstractMessageRef {
60  
61      /***
62       * The cache that holds the message.
63       */
64      private final MessageCache _cache;
65  
66  
67      /***
68       * Construct a new <code>CachedMessageRef</code>.
69       *
70       * @param message    the message to reference
71       * @param persistent if <code>true</code> the message is persistent
72       * @param cache      the cache which manages the message
73       */
74      public CachedMessageRef(MessageImpl message, boolean persistent,
75                              MessageCache cache) {
76          super(message.getMessageId().getId(), persistent);
77  
78          if (cache == null) {
79              throw new IllegalArgumentException("Argument 'cache' is null");
80          }
81          _cache = cache;
82      }
83  
84      /***
85       * Construct a new <code>CachedMessageRef</code>.
86       *
87       * @param messageId  the message to reference
88       * @param persistent if <code>true</code> the message is persistent
89       * @param cache      the cache which manages the message
90       */
91      public CachedMessageRef(String messageId, boolean persistent,
92                              MessageCache cache) {
93          super(messageId, persistent);
94  
95          if (cache == null) {
96              throw new IllegalArgumentException("Argument 'cache' is null");
97          }
98          _cache = cache;
99      }
100 
101     /***
102      * Returns the message associated with this reference.
103      *
104      * @return the associated message, or <code>null</code> if the reference is
105      *         no longer valid
106      * @throws JMSException for any error
107      */
108     public MessageImpl getMessage() throws JMSException {
109         return _cache.getMessage(this);
110     }
111 
112     /***
113      * Destroy the message, irrespective of the number of current references.
114      *
115      * @throws JMSException for any error
116      */
117     public synchronized void destroy() throws JMSException {
118         if (!isDestroyed()) {
119             _cache.destroy(this);
120             setDestroyed();
121         }
122     }
123 
124 }