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 2001-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: QueueConsumerEndpoint.java,v 1.3 2005/08/30 05:30:52 tanderson Exp $
44 */
45 package org.exolab.jms.messagemgr;
46
47 import javax.jms.InvalidSelectorException;
48 import javax.jms.JMSException;
49
50 import org.exolab.jms.message.MessageImpl;
51
52
53 /***
54 * A {@link ConsumerEndpoint} for queues. This object shares access to a
55 * particular queue with other QueueConsumerEndpoint instances.
56 *
57 * @author <a href="mailto:jima@comware.com.au">Jim Alateras</a>
58 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
59 * @version $Revision: 1.3 $ $Date: 2005/08/30 05:30:52 $
60 */
61 public class QueueConsumerEndpoint
62 extends AbstractConsumerEndpoint {
63
64 /***
65 * The destination that this consumer subscribes to.
66 */
67 private final QueueDestinationCache _cache;
68
69
70 /***
71 * Construct a new <code>QueueConsumerEndpoint</code>.
72 *
73 * @param consumerId the identity of this consumer
74 * @param cache the cache to register with
75 * @throws InvalidSelectorException if the selector is not well formed
76 * @throws JMSException if the destination cache can't be
77 * created
78 */
79 public QueueConsumerEndpoint(long consumerId, QueueDestinationCache cache,
80 String selector)
81 throws InvalidSelectorException, JMSException {
82 super(consumerId, cache.getDestination(), selector, false);
83
84 cache.addConsumer(this);
85 _cache = cache;
86 }
87
88 /***
89 * Return the number of unsent messages.
90 *
91 * @return the number of unsent messages
92 */
93 public int getMessageCount() {
94 return _cache.getMessageCount();
95 }
96
97 /***
98 * This event is called when a non-persistent message is added to a
99 * <code>DestinationCache</code>.
100 *
101 * @param handle a handle to the added message
102 * @param message the added message
103 * @return <code>true</code> if the listener accepted the message; otherwise
104 * <code>false</ode>
105 */
106 public boolean messageAdded(MessageHandle handle, MessageImpl message) {
107
108 notifyMessageAvailable();
109 return true;
110 }
111
112 /***
113 * This event is called when a persistent message is added to the
114 * <code>DestinationCache</code>.
115 *
116 * @param handle a handle to the added message
117 * @param message the added message
118 * @return <code>true</code>
119 */
120 public boolean persistentMessageAdded(MessageHandle handle,
121 MessageImpl message) {
122 return messageAdded(handle, message);
123 }
124
125 /***
126 * This event is called when a message is removed from the
127 * <code>DestinationCache</code>.
128 *
129 * @param messageId the identifier of the removed message
130 */
131 public void messageRemoved(String messageId) {
132
133 }
134
135 /***
136 * This event is called when a message is removed from the
137 * <code>DestinationCache</code>
138 *
139 * @param messageId a handle to the removed message
140 */
141 public void persistentMessageRemoved(String messageId) {
142
143 }
144
145 /***
146 * Return the next available message to the client.
147 *
148 * @return the next message, or <code>null</code> if none is available
149 * @throws JMSException for any error
150 * @param cancel
151 */
152 protected MessageHandle doReceive(Condition cancel) throws JMSException {
153 MessageHandle handle = _cache.getMessage(getSelector(), cancel);
154 if (handle instanceof QueueConsumerMessageHandle) {
155
156 ((QueueConsumerMessageHandle) handle).setConsumerId(getId());
157 }
158
159 return handle;
160 }
161
162 /***
163 * Closes this endpoint.
164 */
165 protected void doClose() {
166
167 _cache.removeConsumer(this);
168 }
169
170 }
171