/**
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2002 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */


package org.exolab.castor.mapping.handlers;


import org.exolab.castor.mapping.MapHandler;

/**
 * A Map handler for adding and retreiving key-value pairs from A map. A map handler is instantiated
 * only once, must be thread safe and not use any synchronization.
 *
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $
 */
public final class MapHandlers {
  private static final String J2MAP_CLASSNAME = "java.util.Map";

  private static final String J2MAP_HANDLER_CLASSNAME =
      "org.exolab.castor.mapping.handlers.J2MapHandler";

  private static final MapHandler HASHTABLE_HANDLER = new J1MapHandler();

  private static MapHandler _anymapHandler;

  private static Class _j2mapClass = null;

  static {
    if (_j2mapClass == null) {
      try {
        ClassLoader loader = MapHandlers.class.getClassLoader();
        if (loader != null) {
          _j2mapClass = loader.loadClass(J2MAP_CLASSNAME);
        } else {
          _j2mapClass = Class.forName(J2MAP_CLASSNAME);
        }
        Class handler = Class.forName(J2MAP_HANDLER_CLASSNAME);
        _anymapHandler = (MapHandler) handler.newInstance();
      } catch (ClassNotFoundException cnfe) {
        // -- Probably JDK 1.1 only
      } catch (InstantiationException ie) {
        // -- Probably shouldn't be here, but ignore
        // -- and only JDK 1.1 will be supported.
      } catch (IllegalAccessException iae) {
        // -- Probably shouldn't be here, but ignore
        // -- and only JDK 1.1 will be supported.
      }
    }
  }

  public static MapHandler getHandler(Object object) {
    if (object == null)
      return null;
    return getHandler(object.getClass());
  } // -- getHandler

  public static MapHandler getHandler(Class clazz) {

    if (clazz == null)
      return null;

    if (java.util.Hashtable.class.isAssignableFrom(clazz))
      return HASHTABLE_HANDLER;

    if (_j2mapClass != null) {
      if (_j2mapClass.isAssignableFrom(clazz))
        return _anymapHandler;
    }

    return null;
  } // -- getHandler


} // -- MapHandlers


