KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > exolab > jms > client > JmsConnectionConsumer


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 2000-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42  *
43  * $Id: JmsConnectionConsumer.java,v 1.2 2005/03/18 03:36:37 tanderson Exp $
44  */
45 package org.exolab.jms.client;
46
47 import javax.jms.Connection JavaDoc;
48 import javax.jms.ConnectionConsumer JavaDoc;
49 import javax.jms.Destination JavaDoc;
50 import javax.jms.JMSException JavaDoc;
51 import javax.jms.Message JavaDoc;
52 import javax.jms.MessageConsumer JavaDoc;
53 import javax.jms.MessageListener JavaDoc;
54 import javax.jms.ServerSession JavaDoc;
55 import javax.jms.ServerSessionPool JavaDoc;
56 import javax.jms.Session JavaDoc;
57 import javax.jms.Topic JavaDoc;
58
59 import org.apache.commons.logging.Log;
60 import org.apache.commons.logging.LogFactory;
61
62
63 /**
64  * Implementation of the <code>javax.jms.ConnectionConsumer</code> interface.
65  *
66  * @author <a HREF="mailto:jima@comware.com.au">Jim Alateras</a>
67  * @author <a HREF="mailto:tma@netspace.net.au">Tim Anderson</a>
68  * @version $Revision: 1.2 $ $Date: 2005/03/18 03:36:37 $
69  */
70 class JmsConnectionConsumer
71         implements ConnectionConsumer JavaDoc, MessageListener JavaDoc {
72
73     /**
74      * The session to receive messages via.
75      */
76     private Session JavaDoc _session;
77
78     /**
79      * The consumer of messages.
80      */
81     private MessageConsumer JavaDoc _consumer;
82
83     /**
84      * The server session pool.
85      */
86     private ServerSessionPool JavaDoc _pool;
87
88     /**
89      * The logger
90      */
91     private static final Log _log =
92             LogFactory.getLog(JmsConnectionConsumer.class);
93
94
95     /**
96      * Construct a new <code>JmsConnectionConsumer</code>.
97      *
98      * @param connection the connection which created this
99      * @param destination the destination to access
100      * @param pool the server session pool
101      * @param selector the message selector. May be <code>null</code>
102      * @param maxMessages the maximum number of messages that can be
103      * assigned to a server session at one time
104      * @throws JMSException if the consumer cannot be constructed
105      */
106     public JmsConnectionConsumer(Connection JavaDoc connection, Destination JavaDoc destination,
107                                  ServerSessionPool JavaDoc pool, String JavaDoc selector,
108                                  int maxMessages)
109             throws JMSException JavaDoc {
110         this(connection, destination, null, pool, selector, maxMessages);
111     }
112
113     /**
114      * Construct a new <code>JmsConnectionConsumer</code>.
115      *
116      * @param connection the connection which created this
117      * @param destination the destination to access
118      * @param subscriptionName the durable subscription name. May be
119      * <code>null</code>
120      * @param pool the server session pool
121      * @param selector the message selector. May be <code>null</code>
122      * @param maxMessages the maximum number of messages that can be
123      * assigned to a server session at one time
124      * @throws JMSException if the consumer cannot be constructed
125      */
126     public JmsConnectionConsumer(Connection JavaDoc connection, Destination JavaDoc destination,
127                                  String JavaDoc subscriptionName,
128                                  ServerSessionPool JavaDoc pool, String JavaDoc selector,
129                                  int maxMessages)
130             throws JMSException JavaDoc {
131         if (connection == null) {
132             throw new IllegalArgumentException JavaDoc("Argument 'connection' is null");
133         }
134         if (destination == null) {
135             throw new IllegalArgumentException JavaDoc(
136                     "Argument 'destination' is null");
137         }
138         if (pool == null) {
139             throw new IllegalArgumentException JavaDoc("Argument 'pool' is null");
140         }
141         if (maxMessages <= 0) {
142             throw new IllegalArgumentException JavaDoc(
143                     "Argument 'maxMessages' must be > 0");
144         }
145
146         _pool = pool;
147
148         _session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
149         if (subscriptionName == null) {
150             _consumer = _session.createConsumer(destination, selector, false);
151         } else {
152             _consumer = _session.createDurableSubscriber((Topic JavaDoc) destination,
153                                                          subscriptionName,
154                                                          selector, false);
155         }
156
157         _consumer.setMessageListener(this);
158     }
159
160     /**
161      * Returns the server session pool associated with this connection consumer.
162      *
163      * @return the server session pool used by this connection consumer
164      */
165     public ServerSessionPool JavaDoc getServerSessionPool() {
166         return _pool;
167     }
168
169     /**
170      * Close the connection consumer, freeing any allocated resources.
171      *
172      * @throws JMSException if the consumer cannot be closed
173      */
174     public void close() throws JMSException JavaDoc {
175         try {
176             _consumer.close();
177             _session.close();
178         } finally {
179             _pool = null;
180             _consumer = null;
181             _session = null;
182         }
183     }
184
185     /**
186      * Impmentation of MessageListener.onMessage, to receive messages
187      * from the server. In this most simple case, it loads each message into a
188      * server session and calls the start method.
189      *
190      * @param message the message
191      */
192     public void onMessage(Message JavaDoc message) {
193         try {
194             // not very sophisticated at this point. Simply get a session
195 // from the pool, put the message in it, and start it.
196 ServerSession JavaDoc serverSession = _pool.getServerSession();
197             JmsSession session = (JmsSession) serverSession.getSession();
198             message.acknowledge();
199             session.addMessage(message);
200             serverSession.start();
201         } catch (Exception JavaDoc exception) {
202             _log.error(exception, exception);
203         }
204     }
205
206 }
207
Popular Tags