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1   /*
2    * $Id: ObjectToString.java 19250 2010-08-30 16:53:14Z dirk.olmes $
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.transformer.simple;
12  
13  import org.mule.RequestContext;
14  import org.mule.api.transformer.DiscoverableTransformer;
15  import org.mule.api.transformer.TransformerException;
16  import org.mule.api.transport.OutputHandler;
17  import org.mule.config.i18n.CoreMessages;
18  import org.mule.transformer.AbstractTransformer;
19  import org.mule.transformer.types.DataTypeFactory;
20  import org.mule.util.IOUtils;
21  import org.mule.util.StringMessageUtils;
22  
23  import java.io.ByteArrayOutputStream;
24  import java.io.IOException;
25  import java.io.InputStream;
26  import java.io.UnsupportedEncodingException;
27  
28  /**
29   * <code>ObjectToString</code> transformer is useful for debugging. It will return
30   * human-readable output for various kinds of objects. Right now, it is just coded to
31   * handle Map and Collection objects. Others will be added.
32   */
33  public class ObjectToString extends AbstractTransformer implements DiscoverableTransformer
34  {
35      protected static final int DEFAULT_BUFFER_SIZE = 80;
36  
37      /** Give core transformers a slighty higher priority */
38      private int priorityWeighting = DiscoverableTransformer.DEFAULT_PRIORITY_WEIGHTING + 1;
39  
40      public ObjectToString()
41      {
42          registerSourceType(DataTypeFactory.OBJECT);
43          registerSourceType(DataTypeFactory.BYTE_ARRAY);
44          registerSourceType(DataTypeFactory.INPUT_STREAM);
45          registerSourceType(DataTypeFactory.create(OutputHandler.class));
46          //deliberately set the mime for this transformer to text plain so that other transformers
47          //that serialize string types such as XML or JSON will not match this
48          setReturnDataType(DataTypeFactory.TEXT_STRING);
49      }
50  
51      @Override
52      public Object doTransform(Object src, String encoding) throws TransformerException
53      {
54          String output = "";
55  
56          if (src instanceof InputStream)
57          {
58              InputStream is = (InputStream) src;
59              try
60              {
61                  ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
62                  IOUtils.copy(is, byteOut);
63                  output = new String(byteOut.toByteArray(), encoding);
64              }
65              catch (IOException e)
66              {
67                  throw new TransformerException(CoreMessages.errorReadingStream(), e);
68              }
69              finally
70              {
71                  try
72                  {
73                      is.close();
74                  }
75                  catch (IOException e)
76                  {
77                      logger.warn("Could not close stream", e);
78                  }
79              }
80          }
81          else if (src instanceof OutputHandler)
82          {
83              ByteArrayOutputStream bytes = new ByteArrayOutputStream();
84              
85              try
86              {
87                  ((OutputHandler) src).write(RequestContext.getEvent(), bytes);
88                  
89                  output = new String(bytes.toByteArray(), encoding);
90              }
91              catch (IOException e)
92              {
93                  throw new TransformerException(this, e);
94              }
95              
96              
97          }
98          else if (src instanceof byte[])
99          {
100             try
101             {
102                 output = new String((byte[]) src, encoding);
103             }
104             catch (UnsupportedEncodingException e)
105             {
106                 throw new TransformerException(this, e);
107             }
108         }
109         else
110         {
111             output = StringMessageUtils.toString(src);
112         }
113 
114         return output;
115     }
116 
117     public int getPriorityWeighting()
118     {
119         return priorityWeighting;
120     }
121 
122     public void setPriorityWeighting(int priorityWeighting)
123     {
124         this.priorityWeighting = priorityWeighting;
125     }
126 }