GenericDLQHandler


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4   * by the @authors tag. See the copyright.txt in the distribution for a
5   * full listing of individual contributors.
6   *
7   * This is free software; you can redistribute it and/or modify it
8   * under the terms of the GNU Lesser General Public License as
9   * published by the Free Software Foundation; either version 2.1 of
10  * the License, or (at your option) any later version.
11  *
12  * This software is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this software; if not, write to the Free
19  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21  */
22  package org.jboss.resource.adapter.jms.inflow.dlq;
23  
24  import java.util.HashMap  ;
25  
26  import javax.jms.JMSException  ;
27  import javax.jms.Message  ;
28  
29  /**
30   * A Generic DLQ Handler
31   * 
32   * @author <a HREF="adrian@jboss.com">Adrian Brock</a>
33   * @version $Revision: 38447 $
34   */
35  public class GenericDLQHandler extends JBossMQDLQHandler
36  {
37     /** Resent messages Map<MessageID, Integer> */
38     protected HashMap   resent = new HashMap  ();
39  
40     public void messageDelivered(Message   msg)
41     {
42        try
43        {
44           String   id = msg.getJMSMessageID();
45           if (id == null)
46           {
47              log.error("Message id is null? " + msg);
48              return;
49           }
50  
51           clearResentCounter(id);
52        }
53        catch (Throwable   t)
54        {
55           log.warn("Unexpected error processing delivery notification " + msg, t);
56        }
57     }
58  
59     protected boolean handleDelivery(Message   msg)
60     {
61        // Check for JBossMQ specific
62        boolean handled = super.handleDelivery(msg);
63        if (handled)
64           return true;
65        
66        try
67        {
68           if (msg.propertyExists(JMS_JBOSS_REDELIVERY_COUNT))
69              return false;
70  
71           String   id = msg.getJMSMessageID();
72           if (id == null)
73           {
74              log.error("Message id is null? " + msg);
75              return false;
76           }
77  
78           int count = 0;
79           
80           try
81           {
82              if (msg.propertyExists(PROPERTY_DELIVERY_COUNT))
83                 count = msg.getIntProperty(PROPERTY_DELIVERY_COUNT) - 1;
84           }
85           catch (JMSException   ignored)
86           {
87              count = incrementResentCounter(id);
88           }
89           
90           if (count > maxResent)
91           {
92              warnDLQ(msg, count, maxResent);
93              clearResentCounter(id);
94              return true;
95           }
96        }
97        catch (Throwable   t)
98        {
99           log.warn("Unexpected error checking whether dlq should be used " + msg, t);
100       }
101       
102       return false;
103    }
104    
105    /**
106     * Increment the resent counter for the message id
107     * 
108     * @param id the message id of the message
109     */
110    protected int incrementResentCounter(String   id)
111    {
112       ResentInfo info;
113       synchronized (resent)
114       {
115          info = (ResentInfo) resent.get(id);
116          if (info == null)
117          {
118             info = new ResentInfo();
119             resent.put(id, info);
120          }
121       }
122       return ++info.count;
123    }
124    
125    /**
126     * Remove the resent counter for the message id
127     * 
128     * @param id the message id of the message
129     */
130    protected void clearResentCounter(String   id)
131    {
132       synchronized (resent)
133       {
134          resent.remove(id);
135       }
136    }
137    
138    /**
139     * Resent Info
140     */
141    protected static class ResentInfo
142    {
143       int count = 0;
144    }
145 }
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