Coverage Report - org.mule.registry.TypeBasedTransformerResolver
 
Classes in this File Line Coverage Branch Coverage Complexity
TypeBasedTransformerResolver
0%
0/59
0%
0/30
0
 
 1  
 /*
 2  
  * $Id: TypeBasedTransformerResolver.java 20321 2010-11-24 15:21:24Z 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  
 package org.mule.registry;
 11  
 
 12  
 import org.mule.api.MuleContext;
 13  
 import org.mule.api.MuleException;
 14  
 import org.mule.api.context.MuleContextAware;
 15  
 import org.mule.api.lifecycle.Disposable;
 16  
 import org.mule.api.lifecycle.Initialisable;
 17  
 import org.mule.api.lifecycle.InitialisationException;
 18  
 import org.mule.api.registry.ResolverException;
 19  
 import org.mule.api.registry.TransformerResolver;
 20  
 import org.mule.api.transformer.DataType;
 21  
 import org.mule.api.transformer.DiscoverableTransformer;
 22  
 import org.mule.api.transformer.Transformer;
 23  
 import org.mule.config.i18n.CoreMessages;
 24  
 import org.mule.transformer.TransformerChain;
 25  
 import org.mule.transformer.TransformerWeighting;
 26  
 import org.mule.transformer.simple.ObjectToByteArray;
 27  
 import org.mule.transformer.simple.ObjectToString;
 28  
 import org.mule.transformer.types.SimpleDataType;
 29  
 
 30  
 import java.util.List;
 31  
 import java.util.Map;
 32  
 
 33  
 import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
 34  
 
 35  
 import org.apache.commons.logging.Log;
 36  
 import org.apache.commons.logging.LogFactory;
 37  
 
 38  
 /**
 39  
  * Will discover transformers based on type information only. It looks for transformers that support
 40  
  * the source and result types passed into the method. This resolver only resolves on the first
 41  
  * source type, which is the way transformer resolution working in Mule 2.x.
 42  
  */
 43  0
 public class TypeBasedTransformerResolver implements TransformerResolver, MuleContextAware, Disposable, Initialisable
 44  
 {
 45  
     /**
 46  
      * logger used by this class
 47  
      */
 48  0
     protected transient final Log logger = LogFactory.getLog(TypeBasedTransformerResolver.class);
 49  
 
 50  
     private ObjectToString objectToString;
 51  
     private ObjectToByteArray objectToByteArray;
 52  
 
 53  
     private MuleContext muleContext;
 54  
 
 55  0
     protected Map<String, Transformer> exactTransformerCache = new ConcurrentHashMap/*<String, Transformer>*/(8);
 56  
 
 57  
 
 58  
     public void setMuleContext(MuleContext context)
 59  
     {
 60  0
         this.muleContext = context;
 61  0
     }
 62  
 
 63  
     public void initialise() throws InitialisationException
 64  
     {
 65  
         try
 66  
         {
 67  0
             objectToString = new ObjectToString();
 68  0
             objectToByteArray = new ObjectToByteArray();
 69  0
             muleContext.getRegistry().applyProcessorsAndLifecycle(objectToString);
 70  0
             muleContext.getRegistry().applyProcessorsAndLifecycle(objectToByteArray);
 71  
         }
 72  0
         catch (MuleException e)
 73  
         {
 74  0
             throw new InitialisationException(e, this);
 75  0
         }
 76  0
     }
 77  
 
 78  
     public Transformer resolve(DataType source, DataType result) throws ResolverException
 79  
     {
 80  0
         Transformer transformer = exactTransformerCache.get(source.toString() + result.toString());
 81  0
         if (transformer != null)
 82  
         {
 83  0
             return transformer;
 84  
         }
 85  
 
 86  0
         List<Transformer> trans = muleContext.getRegistry().lookupTransformers(source, result);
 87  
 
 88  0
         transformer = getNearestTransformerMatch(trans, source.getType(), result.getType());
 89  
         //If an exact mach is not found, we have a 'second pass' transformer that can be used to converting to String or
 90  
         //byte[]
 91  
         Transformer secondPass;
 92  
 
 93  0
         if (transformer == null)
 94  
         {
 95  
             //If no transformers were found but the outputType type is String or byte[] we can perform a more general search
 96  
             // using Object.class and then convert to String or byte[] using the second pass transformer
 97  0
             if (result.getType().equals(String.class))
 98  
             {
 99  0
                 secondPass = objectToString;
 100  
             }
 101  0
             else if (result.getType().equals(byte[].class))
 102  
             {
 103  0
                 secondPass = objectToByteArray;
 104  
             }
 105  
             else
 106  
             {
 107  0
                 return null;
 108  
             }
 109  
             //Perform a more general search
 110  0
             trans = muleContext.getRegistry().lookupTransformers(source, new SimpleDataType(Object.class));
 111  
 
 112  0
             transformer = getNearestTransformerMatch(trans, source.getType(), result.getType());
 113  0
             if (transformer != null)
 114  
             {
 115  0
                 transformer = new TransformerChain(transformer, secondPass);
 116  
                 try
 117  
                 {
 118  0
                     muleContext.getRegistry().registerTransformer(transformer);
 119  
                 }
 120  0
                 catch (MuleException e)
 121  
                 {
 122  0
                     throw new ResolverException(e.getI18nMessage(), e);
 123  0
                 }
 124  
             }
 125  
         }
 126  
 
 127  0
         if (transformer != null)
 128  
         {
 129  0
             exactTransformerCache.put(source.toString() + result.toString(), transformer);
 130  
         }
 131  0
         return transformer;
 132  
     }
 133  
 
 134  
     protected Transformer getNearestTransformerMatch(List<Transformer> trans, Class input, Class output) throws ResolverException
 135  
     {
 136  0
         if (trans.size() > 1)
 137  
         {
 138  0
             if (logger.isDebugEnabled())
 139  
             {
 140  0
                 logger.debug("Comparing transformers for best match: input = " + input + " output = " + output + " Possible transformers = " + trans);
 141  
             }
 142  0
             TransformerWeighting weighting = null;
 143  0
             for (Transformer transformer : trans)
 144  
             {
 145  0
                 TransformerWeighting current = new TransformerWeighting(input, output, transformer);
 146  0
                 if (weighting == null)
 147  
                 {
 148  0
                     weighting = current;
 149  
                 }
 150  
                 else
 151  
                 {
 152  0
                     int compare = current.compareTo(weighting);
 153  0
                     if (compare == 1)
 154  
                     {
 155  0
                         weighting = current;
 156  
                     }
 157  0
                     else if (compare == 0)
 158  
                     {
 159  
                         //We may have two transformers that are exactly the same, in which case we can use either i.e. use the current
 160  0
                         if (!weighting.getTransformer().getClass().equals(current.getTransformer().getClass()))
 161  
                         {
 162  0
                             throw new ResolverException(CoreMessages.transformHasMultipleMatches(input, output,
 163  
                                     current.getTransformer(), weighting.getTransformer()));
 164  
                         }
 165  
                     }
 166  
                 }
 167  0
             }
 168  0
             return weighting.getTransformer();
 169  
         }
 170  0
         else if (trans.size() == 0)
 171  
         {
 172  0
             return null;
 173  
         }
 174  
         else
 175  
         {
 176  0
             return trans.get(0);
 177  
         }
 178  
     }
 179  
 
 180  
     public void dispose()
 181  
     {
 182  0
         exactTransformerCache.clear();
 183  0
     }
 184  
 
 185  
     public void transformerChange(Transformer transformer, RegistryAction registryAction)
 186  
     {
 187  0
         if (transformer instanceof DiscoverableTransformer)
 188  
         {
 189  0
             exactTransformerCache.clear();
 190  
         }
 191  0
     }
 192  
 }