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1   /*
2    * $Id: MuleSessionHandler.java 7976 2007-08-21 14:26:13Z dirk.olmes $
3    * --------------------------------------------------------------------------------------
4    * Copyright (c) MuleSource, Inc.  All rights reserved.  http://www.mulesource.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.impl;
12  
13  import org.mule.config.MuleProperties;
14  import org.mule.config.i18n.CoreMessages;
15  import org.mule.transformers.codec.Base64Decoder;
16  import org.mule.transformers.codec.Base64Encoder;
17  import org.mule.umo.UMOException;
18  import org.mule.umo.UMOMessage;
19  import org.mule.umo.UMOSession;
20  import org.mule.umo.provider.UMOSessionHandler;
21  import org.mule.umo.transformer.UMOTransformer;
22  
23  import java.io.UnsupportedEncodingException;
24  import java.util.Iterator;
25  import java.util.StringTokenizer;
26  
27  import org.apache.commons.logging.Log;
28  import org.apache.commons.logging.LogFactory;
29  
30  /**
31   * A default session handler used to store and retrieve session information on an
32   * event. The MuleSession information is stored as a header on the message (does not
33   * support Tcp, Udp, etc. unless the UMOMessage object is serialised across the
34   * wire). The session is stored in the "MULE_SESSION" property as String key/value
35   * pairs that are Base64 encoded, for example:
36   * ID=dfokokdf-3ek3oke-dkfokd;MySessionProp1=Value1;MySessionProp2=Value2
37   */
38  public class MuleSessionHandler implements UMOSessionHandler
39  {
40  
41      /**
42       * logger used by this class
43       */
44      protected transient Log logger = LogFactory.getLog(getClass());
45  
46      private static UMOTransformer encoder = new Base64Encoder();
47      private static UMOTransformer decoder = new Base64Decoder();
48  
49      public void retrieveSessionInfoFromMessage(UMOMessage message, UMOSession session) throws UMOException
50      {
51          String sessionId = (String) message.removeProperty(MuleProperties.MULE_SESSION_ID_PROPERTY);
52          Object sessionHeader = message.removeProperty(MuleProperties.MULE_SESSION_PROPERTY);
53  
54          if (sessionId != null)
55          {
56              // TODO Mule 2.0 grab session from the context
57              throw new IllegalStateException(
58                  "This session handler does not know how to look up session information for session id: "
59                                  + sessionId);
60          }
61          if (sessionHeader != null)
62          {
63              String sessionString = null;
64              try
65              {
66                  sessionString = new String((byte[]) decoder.transform(sessionHeader), message.getEncoding());
67              }
68              catch (UnsupportedEncodingException e)
69              {
70                  sessionString = new String((byte[]) decoder.transform(sessionHeader));
71              }
72              if (logger.isDebugEnabled())
73              {
74                  logger.debug("Parsing session header: " + sessionString);
75              }
76              String pair;
77              String name;
78              String value;
79              for (StringTokenizer stringTokenizer = new StringTokenizer(sessionString, ";"); stringTokenizer.hasMoreTokens();)
80              {
81                  pair = stringTokenizer.nextToken();
82                  int i = pair.indexOf("=");
83                  if (i == -1)
84                  {
85                      throw new IllegalArgumentException(
86                          CoreMessages.sessionValueIsMalformed(pair).toString());
87                  }
88                  name = pair.substring(0, i).trim();
89                  value = pair.substring(i + 1).trim();
90                  session.setProperty(name, value);
91                  if (logger.isDebugEnabled())
92                  {
93                      logger.debug("Added Session variable: " + pair);
94                  }
95              }
96  
97          }
98      }
99  
100     public void storeSessionInfoToMessage(UMOSession session, UMOMessage message) throws UMOException
101     {
102         StringBuffer buf = new StringBuffer();
103         buf.append(getSessionIDKey()).append("=").append(session.getId());
104         for (Iterator iterator = session.getPropertyNames(); iterator.hasNext();)
105         {
106             Object o = iterator.next();
107             buf.append(";");
108             buf.append(o).append("=").append(session.getProperty(o));
109             if (logger.isDebugEnabled())
110             {
111                 logger.debug("Adding property to session header: " + o + "=" + session.getProperty(o));
112             }
113         }
114         String sessionString = buf.toString();
115         if (logger.isDebugEnabled())
116         {
117             logger.debug("Adding session header to message: " + sessionString);
118         }
119         sessionString = (String) encoder.transform(sessionString);
120         message.setProperty(MuleProperties.MULE_SESSION_PROPERTY, sessionString);
121     }
122 
123     public String getSessionIDKey()
124     {
125         return "ID";
126     }
127 }