Coverage Report - org.mule.processor.chain.DefaultMessageProcessorChainBuilder
 
Classes in this File Line Coverage Branch Coverage Complexity
DefaultMessageProcessorChainBuilder
0%
0/36
0%
0/16
0
 
 1  
 /*
 2  
  * $Id: DefaultMessageProcessorChainBuilder.java 20781 2010-12-16 13:19:09Z dfeist $
 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.processor.chain;
 12  
 
 13  
 import org.mule.api.MuleException;
 14  
 import org.mule.api.construct.FlowConstruct;
 15  
 import org.mule.api.processor.InterceptingMessageProcessor;
 16  
 import org.mule.api.processor.MessageProcessor;
 17  
 import org.mule.api.processor.MessageProcessorBuilder;
 18  
 import org.mule.api.processor.MessageProcessorChain;
 19  
 
 20  
 import java.util.ArrayList;
 21  
 import java.util.Collections;
 22  
 import java.util.LinkedList;
 23  
 import java.util.List;
 24  
 
 25  
 /**
 26  
  * <p>
 27  
  * Constructs a chain of {@link MessageProcessor}s and wraps the invocation of the chain in a composite
 28  
  * MessageProcessor. Both MessageProcessors and InterceptingMessageProcessor's can be chained together
 29  
  * arbitrarily in a single chain. InterceptingMessageProcessors simply intercept the next MessageProcessor in
 30  
  * the chain. When other non-intercepting MessageProcessors are used an adapter is used internally to chain
 31  
  * the MessageProcessor with the next in the chain.
 32  
  * </p>
 33  
  * <p>
 34  
  * The MessageProcessor instance that this builder builds can be nested in other chains as required.
 35  
  * </p>
 36  
  */
 37  0
 public class DefaultMessageProcessorChainBuilder extends AbstractMessageProcessorChainBuilder
 38  
 {
 39  
 
 40  
     public DefaultMessageProcessorChainBuilder()
 41  0
     {
 42  
         // empty
 43  0
     }
 44  
 
 45  
     public DefaultMessageProcessorChainBuilder(FlowConstruct flowConstruct)
 46  0
     {
 47  0
         this.flowConstruct = flowConstruct;
 48  0
     }
 49  
 
 50  
     /**
 51  
      * This builder supports the chaining together of message processors that intercept and also those that
 52  
      * don't. While one can iterate over message processor intercepting message processors need to be chained
 53  
      * together. One solution is make all message processors intercepting (via adaption) and chain them all
 54  
      * together, this results in huge stack traces and recursive calls with adaptor. The alternative is to
 55  
      * build the chain in such a way that we iterate when we can and chain where we need to. <br>
 56  
      * We iterate over the list of message processor to be chained together in reverse order collecting up
 57  
      * those that can be iterated over in a temporary list, as soon as we have an intercepting message
 58  
      * processor we create a DefaultMessageProcessorChain using the temporary list and set it as a listener of
 59  
      * the intercepting message processor and then we continue with the algorithm
 60  
      */
 61  
     public MessageProcessorChain build() throws MuleException
 62  
     {
 63  0
         LinkedList<MessageProcessor> tempList = new LinkedList<MessageProcessor>();
 64  
 
 65  
         // Start from last but one message processor and work backwards
 66  0
         for (int i = processors.size() - 1; i >= 0; i--)
 67  
         {
 68  0
             MessageProcessor processor = initializeMessageProcessor(processors.get(i));
 69  0
             if (processor instanceof InterceptingMessageProcessor)
 70  
             {
 71  0
                 InterceptingMessageProcessor interceptingProcessor = (InterceptingMessageProcessor) processor;
 72  
                 // Processor is intercepting so we can't simply iterate
 73  0
                 if (i + 1 < processors.size())
 74  
                 {
 75  
                     // The current processor is not the last in the list
 76  0
                     if (tempList.isEmpty())
 77  
                     {
 78  0
                         interceptingProcessor.setListener(initializeMessageProcessor(processors.get(i + 1)));
 79  
                     }
 80  0
                     else if (tempList.size() == 1)
 81  
                     {
 82  0
                         interceptingProcessor.setListener(tempList.get(0));
 83  
                     }
 84  
                     else
 85  
                     {
 86  0
                         final DefaultMessageProcessorChain chain = new DefaultMessageProcessorChain(
 87  
                             "(inner iterating chain) of " + name, new ArrayList<MessageProcessor>(tempList));
 88  0
                         interceptingProcessor.setListener(chain);
 89  
                     }
 90  
                 }
 91  0
                 tempList = new LinkedList<MessageProcessor>(Collections.singletonList(processor));
 92  0
             }
 93  
             else
 94  
             {
 95  
                 // Processor is not intercepting so we can invoke it using iteration
 96  
                 // (add to temp list)
 97  0
                 tempList.addFirst(initializeMessageProcessor(processor));
 98  
             }
 99  
         }
 100  
         // Create the final chain using the current tempList after reserve iteration is complete. This temp
 101  
         // list contains the first n processors in the chain that are not intercepting.. with processor n+1
 102  
         // having been injected as the listener of processor n
 103  0
         final DefaultMessageProcessorChain chain = new DefaultMessageProcessorChain(name,
 104  
             new ArrayList<MessageProcessor>(tempList));
 105  
 
 106  
         // Wrap with something that can apply lifecycle to all processors which are otherwise not visable from
 107  
         // DefaultMessageProcessorChain
 108  0
         return new InterceptingChainLifecycleWrapper(chain, processors, "wrapper for " + name);
 109  
     }
 110  
 
 111  
     public DefaultMessageProcessorChainBuilder chain(MessageProcessor... processors)
 112  
     {
 113  0
         for (MessageProcessor messageProcessor : processors)
 114  
         {
 115  0
             this.processors.add(messageProcessor);
 116  
         }
 117  0
         return this;
 118  
     }
 119  
 
 120  
     public DefaultMessageProcessorChainBuilder chain(List<MessageProcessor> processors)
 121  
     {
 122  0
         if (processors != null)
 123  
         {
 124  0
             this.processors.addAll(processors);
 125  
         }
 126  0
         return this;
 127  
     }
 128  
 
 129  
     public DefaultMessageProcessorChainBuilder chain(MessageProcessorBuilder... builders)
 130  
     {
 131  0
         for (MessageProcessorBuilder messageProcessorBuilder : builders)
 132  
         {
 133  0
             this.processors.add(messageProcessorBuilder);
 134  
         }
 135  0
         return this;
 136  
     }
 137  
 
 138  
     public DefaultMessageProcessorChainBuilder chainBefore(MessageProcessor processor)
 139  
     {
 140  0
         this.processors.add(0, processor);
 141  0
         return this;
 142  
     }
 143  
 
 144  
     public DefaultMessageProcessorChainBuilder chainBefore(MessageProcessorBuilder builder)
 145  
     {
 146  0
         this.processors.add(0, builder);
 147  0
         return this;
 148  
     }
 149  
 }