MantaQueueBrowser


1   /*
2    * Copyright 2002 by
3    * <a HREF="http://www.coridan.com">Coridan</a>
4    * <a HREF="mailto: support@coridan.com ">support@coridan.com</a>
5    *
6    * The contents of this file are subject to the Mozilla Public License Version
7    * 1.1 (the "License"); you may not use this file except in compliance with the
8    * License.  You may obtain a copy of the License at
9    * http://www.mozilla.org/MPL/
10   *
11   * Software distributed under the License is distributed on an "AS IS" basis,
12   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13   * for the specific language governing rights and limitations under the
14   * License.
15   *
16   * The Original Code is "MantaRay" (TM).
17   *
18   * The Initial Developer of the Original Code is Nimo.
19   * Portions created by the Initial Developer are Copyright (C) 2006
20   * Coridan Inc.  All Rights Reserved.
21   *
22   * Contributor(s): all the names of the contributors are added in the source
23   * code where applicable.
24   *
25   * Alternatively, the contents of this file may be used under the terms of the
26   * LGPL license (the "GNU LESSER GENERAL PUBLIC LICENSE"), in which case the
27   * provisions of LGPL are applicable instead of those above.  If you wish to
28   * allow use of your version of this file only under the terms of the LGPL
29   * License and not to allow others to use your version of this file under
30   * the MPL, indicate your decision by deleting the provisions above and
31   * replace them with the notice and other provisions required by the LGPL.
32   * If you do not delete the provisions above, a recipient may use your version
33   * of this file under either the MPL or the GNU LESSER GENERAL PUBLIC LICENSE.
34   
35   *
36   * This library is free software; you can redistribute it and/or modify it
37   * under the terms of the MPL as stated above or under the terms of the GNU
38   * Lesser General Public License as published by the Free Software Foundation;
39   * either version 2.1 of the License, or any later version.
40   *
41   * This library is distributed in the hope that it will be useful, but WITHOUT
42   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
43   * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
44   * License for more details.
45   */
46  package org.mr.api.jms;
47  
48  import java.util.Enumeration  ;
49  import java.util.Vector  ;
50  import java.io.Serializable  ;
51  import javax.jms.JMSException  ;
52  import javax.jms.Message  ;
53  import javax.jms.Queue  ;
54  import javax.jms.QueueBrowser  ;
55  
56  import org.mr.api.jms.selector.syntax.Selector;
57  import org.mr.kernel.services.ServiceConsumer;
58  import org.mr.core.protocol.MantaBusMessage;
59  /**
60   * This class represents a
61   * 
62   * @version 1.0
63   * @since Jan 19, 2004
64   * @author Nimo
65   *
66   */
67  public class MantaQueueBrowser implements Serializable  , QueueBrowser  {
68  
69      /**
70       * Creates a new QueueBrowser.
71       * 
72       * @param clientId - the client id for this browser.
73       * @param sess - the creating session
74       * @param queue - the queue to browse.
75       * @param messageSelector - a message selector
76       * @param service - the MantaService for this browser.
77       * @throws JMSException
78       */
79      public MantaQueueBrowser(String   clientId, MantaSession sess, Queue   queue,String   messageSelector, ServiceConsumer service) throws JMSException  {
80          theQueue = queue;
81          creatingSession = sess;
82          this.clientId = clientId;
83          this.service = service;
84          
85          if (messageSelector!=null && messageSelector.length()==0)
86              messageSelector = null;
87          
88          new Selector(messageSelector);
89          theMessageSelector = messageSelector;
90                  
91      }//MantaQueueBrowser
92      
93      /**
94       *  Closes the <CODE>QueueBrowser</CODE>.
95       *
96       * <P>Since a provider may allocate some resources on behalf of a 
97       * QueueBrowser outside the Java virtual machine, clients should close them
98       * when they 
99       * are not needed. Relying on garbage collection to eventually reclaim 
100      * these resources may not be timely enough.
101      *
102      * @exception JMSException if the JMS provider fails to close this
103      *                         browser due to some internal error.
104      */
105     public void close() throws JMSException   {
106         creatingSession.removeBrowser(this);
107         creatingSession = null;
108         theMessageSelector=null;
109         theQueue=null;
110         service=null;
111         clientId=null;
112     }
113 
114     /** 
115      * Gets an enumeration for browsing the current queue messages in the
116      * order they would be received.
117      *
118      * @return an enumeration for browsing the messages
119      *  
120      * @exception JMSException if the JMS provider fails to get the
121      *                         enumeration for this browser
122      *                         due to some internal error.
123      */
124     public Enumeration   getEnumeration() throws JMSException   {
125         //this is the MantaBusMessages Enumeration.
126         Enumeration   busMessages = creatingSession.getMessagesFor(this);
127         
128         Vector   messages = new Vector  ();
129         while (busMessages.hasMoreElements()) {
130             Message   orig =MantaMessageConsumer.convertToJMSMessage((MantaBusMessage)busMessages.nextElement(),creatingSession); 
131             messages.add(orig);
132         }
133         busMessages = null;
134         
135         return messages.elements();
136     }
137 
138     /** 
139      * Gets this queue browser's message selector expression.
140      *  
141      * @return this queue browser's message selector, or null if no
142      *         message selector exists for the message consumer (that is, if 
143      *         the message selector was not set or was set to null or the 
144      *         empty string)
145      *
146      * @exception JMSException if the JMS provider fails to get the
147      *                         message selector for this browser
148      *                         due to some internal error.
149      */
150     public String   getMessageSelector() throws JMSException   {
151         return theMessageSelector;
152     }//getMessageSelector
153     
154 
155     /**
156      *  Gets the queue associated with this queue browser.
157      * 
158      * @return the queue
159      *  
160      * @exception JMSException if the JMS provider fails to get the
161      *                         queue associated with this browser
162      *                         due to some internal error.
163      */
164     public Queue   getQueue() throws JMSException   {
165         return theQueue;
166     }//getQueue
167     
168     /**
169      * Gets the service associated with this browser.
170      * 
171      * @return - the service object.
172      */
173     public ServiceConsumer getService() {
174         return service;
175     }
176     private Queue   theQueue = null;
177     
178     /**
179      * Gets the client id for this browser.
180      * 
181      * @return the client id
182      *
183      */
184     String   getClientId() {
185         return this.clientId;
186     }
187     
188     //The message selector object associated with the queue browser
189     protected String   theMessageSelector = null;
190     
191     private MantaSession creatingSession;
192     
193     String   clientId;
194     ServiceConsumer service;
195 }
196
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags