View Javadoc
1   /**
2    * Redistribution and use of this software and associated documentation
3    * ("Software"), with or without modification, are permitted provided
4    * that the following conditions are met:
5    *
6    * 1. Redistributions of source code must retain copyright
7    *    statements and notices.  Redistributions must also contain a
8    *    copy of this document.
9    *
10   * 2. Redistributions in binary form must reproduce the
11   *    above copyright notice, this list of conditions and the
12   *    following disclaimer in the documentation and/or other
13   *    materials provided with the distribution.
14   *
15   * 3. The name "Exolab" must not be used to endorse or promote
16   *    products derived from this Software without prior written
17   *    permission of Intalio, Inc.  For written permission,
18   *    please contact info@exolab.org.
19   *
20   * 4. Products derived from this Software may not be called "Exolab"
21   *    nor may "Exolab" appear in their names without prior written
22   *    permission of Intalio, Inc. Exolab is a registered
23   *    trademark of Intalio, Inc.
24   *
25   * 5. Due credit should be given to the Exolab Project
26   *    (http://www.exolab.org/).
27   *
28   * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
29   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
32   * INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39   * OF THE POSSIBILITY OF SUCH DAMAGE.
40   *
41   * Copyright 2002 (C) Intalio, Inc. All Rights Reserved.
42   *
43   * $Id$
44   */
45  
46  
47  package org.exolab.castor.mapping.handlers;
48  
49  
50  import org.exolab.castor.mapping.MapHandler;
51  
52  /**
53   * A Map handler for adding and retreiving key-value pairs from
54   * A map. A map handler is instantiated only once, must be thread
55   * safe and not use any synchronization.
56   *
57   * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
58   * @version $Revision$ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $
59   */
60  public final class MapHandlers {
61      private static final String J2MAP_CLASSNAME = "java.util.Map";
62      
63      private static final String J2MAP_HANDLER_CLASSNAME
64          = "org.exolab.castor.mapping.handlers.J2MapHandler";
65  
66      private static final MapHandler HASHTABLE_HANDLER = new J1MapHandler();
67  
68      private static MapHandler _anymapHandler;
69  
70      private static Class _j2mapClass = null;
71  
72      static {
73          if (_j2mapClass == null) {
74              try {
75                  ClassLoader loader = MapHandlers.class.getClassLoader();
76                  if (loader != null) {
77                      _j2mapClass = loader.loadClass(J2MAP_CLASSNAME);
78                  } else {
79                      _j2mapClass = Class.forName(J2MAP_CLASSNAME);
80                  }
81                  Class handler = Class.forName(J2MAP_HANDLER_CLASSNAME);
82                  _anymapHandler = (MapHandler) handler.newInstance();
83              } catch (ClassNotFoundException cnfe) {
84                  //-- Probably JDK 1.1 only
85              } catch(InstantiationException ie) {
86                  //-- Probably shouldn't be here, but ignore
87                  //-- and only JDK 1.1 will be supported.
88              } catch(IllegalAccessException iae) {
89                  //-- Probably shouldn't be here, but ignore
90                  //-- and only JDK 1.1 will be supported.
91              }
92          }
93      }
94  
95      public static MapHandler getHandler(Object object) {
96          if (object == null) return null;
97          return getHandler(object.getClass());
98      } //-- getHandler
99  
100     public static MapHandler getHandler(Class clazz) {
101 
102         if (clazz == null) return null;
103 
104         if (java.util.Hashtable.class.isAssignableFrom(clazz))
105             return HASHTABLE_HANDLER;
106 
107         if (_j2mapClass != null) {
108            if (_j2mapClass.isAssignableFrom(clazz))
109                 return _anymapHandler;
110         }
111 
112         return null;
113     } //-- getHandler
114 
115 
116 } //-- MapHandlers
117 
118 
119