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1   /**********************************************************************
2    * MyJsonAdapter.java
3    * created on 05.11.2006 by netseeker
4    * $Id: MyJsonAdapter.java,v 1.1 2007/02/11 15:42:20 netseeker Exp $
5    * $Log: MyJsonAdapter.java,v $
6    * Revision 1.1  2007/02/11 15:42:20  netseeker
7    * *** empty log message ***
8    *
9    * Revision 1.2  2006/11/05 17:13:09  netseeker
10   * added source documentation
11   *
12   * Revision 1.1  2006/11/05 16:33:37  netseeker
13   * changed adapter connection handling
14   * added support for JSON with different JSON-adapters (XStream,JSON-lib,MyJSON)
15   *
16   *
17   * ====================================================================
18   *
19   *  Copyright 2005-2006 netseeker aka Michael Manske
20   *
21   *  Licensed under the Apache License, Version 2.0 (the "License");
22   *  you may not use this file except in compliance with the License.
23   *  You may obtain a copy of the License at
24   *
25   *      http://www.apache.org/licenses/LICENSE-2.0
26   *
27   *  Unless required by applicable law or agreed to in writing, software
28   *  distributed under the License is distributed on an "AS IS" BASIS,
29   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
30   *  See the License for the specific language governing permissions and
31   *  limitations under the License.
32   * ====================================================================
33   *
34   * This file is part of the EJOE framework.
35   * For more information on the author, please see
36   * <http://www.manskes.de/>.
37   *
38   *********************************************************************/
39  package de.netseeker.ejoe.adapter.json;
40  
41  import java.io.InputStream;
42  import java.io.OutputStream;
43  
44  import org.myjson.json.Parser;
45  import org.myjson.json.Serializer;
46  
47  import de.netseeker.ejoe.adapter.UTF8StringAdapter;
48  
49  /***
50   * Multimode SerializeAdapter supporting JSON via the MyJSON library.
51   * By default this adapter is write-only: It is able to serialize Objects to JSON
52   * but does just return JSON strings on read operations.
53   * The read mode can be switched but then Objects according to what MyJSON creates
54   * will be returned. 
55   * @author netseeker
56   * @since 0.3.9.1
57   * @see <a href="http://www.ahristov.com/myjson/">MyJSON</a>
58   */
59  public class MyJsonAdapter extends UTF8StringAdapter
60  {
61      /***
62       * 
63       */
64      private static final long serialVersionUID = 1L;
65  
66      private boolean           _writeOnly;
67  
68      /***
69       * Creates a write-only instance of this adapter.
70       * It will write Object instances to JSON but will
71       * just return JSON string representations on read operations.
72       */
73      public MyJsonAdapter()
74      {
75          this( true );
76      }
77  
78      /***
79       * Creates either a write-only or a mixed-mode instance of
80       * this adapter.
81       * In write-only mode it will write Object instances to JSON but will
82       * just return JSON string representations on read operations.
83       * In mixed-mode Objects according to what MyJSON creates will be returned on read operations.
84       * @param writeOnly whether to uses write-only mode or not
85       */
86      public MyJsonAdapter(boolean writeOnly)
87      {
88          _writeOnly = writeOnly;
89      }
90  
91      /*
92       * (non-Javadoc)
93       * 
94       * @see de.netseeker.ejoe.adapter.UTF8StringAdapter#read(java.io.InputStream)
95       */
96      public Object read( InputStream in ) throws Exception
97      {
98          String json = (String) super.read( in );
99          if ( _writeOnly )
100         {
101             return json;
102         }
103         else
104         {
105             return Parser.parse( json );
106         }
107     }
108 
109     /*
110      * (non-Javadoc)
111      * 
112      * @see de.netseeker.ejoe.adapter.UTF8StringAdapter#write(java.lang.Object, java.io.OutputStream)
113      */
114     public void write( Object obj, OutputStream out ) throws Exception
115     {
116         String json = Serializer.serializeObject( obj );
117         super.write( json, out );
118     }
119 
120     /*
121      * (non-Javadoc)
122      * 
123      * @see de.netseeker.ejoe.adapter.UTF8StringAdapter#getContentType()
124      */
125     public String getContentType()
126     {
127         return "application/json";
128     }
129 }