Coverage Report - org.mule.transport.jms.redelivery.AutoDiscoveryRedeliveryHandlerFactory
 
Classes in this File Line Coverage Branch Coverage Complexity
AutoDiscoveryRedeliveryHandlerFactory
0%
0/32
0%
0/14
0
 
 1  
 /*
 2  
  * $Id: AutoDiscoveryRedeliveryHandlerFactory.java 20501 2010-12-08 00:52:19Z tcarlson $
 3  
  * --------------------------------------------------------------------------------------
 4  
  * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 5  
  *
 6  
  * The software in this package is published under the terms of the CPAL v1.0
 7  
  * license, a copy of which has been included with this distribution in the
 8  
  * LICENSE.txt file.
 9  
  */
 10  
 
 11  
 package org.mule.transport.jms.redelivery;
 12  
 
 13  
 import org.mule.config.i18n.CoreMessages;
 14  
 import org.mule.transport.jms.JmsConnector;
 15  
 import org.mule.transport.jms.JmsConstants;
 16  
 
 17  
 import java.util.Enumeration;
 18  
 import java.util.concurrent.atomic.AtomicReference;
 19  
 
 20  
 import javax.jms.ConnectionMetaData;
 21  
 import javax.jms.JMSException;
 22  
 
 23  
 import org.apache.commons.logging.Log;
 24  
 import org.apache.commons.logging.LogFactory;
 25  
 
 26  
 /**
 27  
  * This factory will consult JMS connection metadata for supported optional properties and use
 28  
  * those, if available, otherwise falling back to the manual counting of redeliveries.
 29  
  *
 30  
  * @see CountingRedeliveryHandlerFactory
 31  
  * @see org.mule.transport.jms.redelivery.JmsXRedeliveryHandlerFactory
 32  
  * @see javax.jms.ConnectionMetaData
 33  
  */
 34  
 public class AutoDiscoveryRedeliveryHandlerFactory implements RedeliveryHandlerFactory
 35  
 {
 36  0
     protected final Log logger = LogFactory.getLog(getClass());
 37  
 
 38  0
     protected AtomicReference<RedeliveryHandler> delegateHandler = new AtomicReference<RedeliveryHandler>(null);
 39  
 
 40  
     protected JmsConnector connector;
 41  
 
 42  
     public AutoDiscoveryRedeliveryHandlerFactory(JmsConnector connector)
 43  0
     {
 44  0
         if (connector == null)
 45  
         {
 46  0
             throw new IllegalArgumentException(CoreMessages.objectIsNull("connector").getMessage());
 47  
         }
 48  0
         this.connector = connector;
 49  0
     }
 50  
 
 51  
     public RedeliveryHandler create()
 52  
     {
 53  
         RedeliveryHandler result;
 54  
 
 55  
         // initialize, accounting for concurrency
 56  0
         if (delegateHandler.get() == null)
 57  
         {
 58  0
             RedeliveryHandler newInstance = createInstance();
 59  0
             boolean ok = delegateHandler.compareAndSet(null, newInstance);
 60  0
             if (!ok)
 61  
             {
 62  
                 // someone was faster to initialize it, use this ref instead
 63  0
                 result = delegateHandler.get();
 64  
             }
 65  
             else
 66  
             {
 67  0
                 result = newInstance;
 68  
             }
 69  0
         }
 70  
         else
 71  
         {
 72  
             // just re-use existing handler
 73  0
             result = delegateHandler.get();
 74  
         }
 75  
 
 76  0
         return result;
 77  
     }
 78  
 
 79  
     /**
 80  
      * Create an instance using the discovery mechanism.
 81  
      *
 82  
      * @return an implementation based on the results of discovery
 83  
      */
 84  
     protected RedeliveryHandler createInstance()
 85  
     {
 86  
         RedeliveryHandler newInstance;
 87  
         try
 88  
         {
 89  0
             ConnectionMetaData metaData = connector.getConnection().getMetaData();
 90  0
             boolean supportsDeliveryCount = false;
 91  0
             final Enumeration propNames = metaData.getJMSXPropertyNames();
 92  0
             while (propNames.hasMoreElements())
 93  
             {
 94  0
                 String p = (String) propNames.nextElement();
 95  0
                 if (JmsConstants.JMS_X_DELIVERY_COUNT.equals(p))
 96  
                 {
 97  0
                     supportsDeliveryCount = true;
 98  0
                     break;
 99  
                 }
 100  0
             }
 101  
 
 102  0
             newInstance = (supportsDeliveryCount) ? new JmsXRedeliveryHandler() : new CountingRedeliveryHandler();
 103  
         }
 104  0
         catch (JMSException e)
 105  
         {
 106  
             // fallback to defaults
 107  0
             newInstance = new CountingRedeliveryHandler();
 108  0
         }
 109  
 
 110  0
         if (logger.isDebugEnabled())
 111  
         {
 112  0
             logger.debug("Using " + newInstance.getClass().getName());
 113  
         }
 114  
 
 115  0
         return newInstance;
 116  
     }
 117  
 
 118  
 }