MapDeserializer.java

/*
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 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 end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``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 CAUCHO TECHNOLOGY 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.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian4.io;

import java.io.IOException;
import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * Deserializing a JDK 1.2 Map.
 */
public class MapDeserializer extends AbstractMapDeserializer {
  private Class<?> _type;
  private Constructor<?> _ctor;
  
  public MapDeserializer(Class<?> type)
  {
    if (type == null)
      type = HashMap.class;
    
    _type = type;

    Constructor<?> []ctors = type.getConstructors();
    for (int i = 0; i < ctors.length; i++) {
      if (ctors[i].getParameterTypes().length == 0)
	_ctor = ctors[i];
    }

    if (_ctor == null) {
      try {
	_ctor = HashMap.class.getConstructor(new Class[0]);
      } catch (Exception e) {
	throw new IllegalStateException(e);
      }
    }
  }
  
  public Class<?> getType()
  {
    if (_type != null)
      return _type;
    else
      return HashMap.class;
  }

  public Object readMap(AbstractHessianInput in)
    throws IOException
  {
    Map map;
    
    if (_type == null)
      map = new HashMap();
    else if (_type.equals(Map.class))
      map = new HashMap();
    else if (_type.equals(SortedMap.class))
      map = new TreeMap();
    else {
      try {
        map = (Map) _ctor.newInstance();
      } catch (Exception e) {
        throw new IOExceptionWrapper(e);
      }
    }

    in.addRef(map);

    while (! in.isEnd()) {
      map.put(in.readObject(), in.readObject());
    }

    in.readEnd();

    return map;
  }

  @Override
  public Object readObject(AbstractHessianInput in,
			   Object []fields)
    throws IOException
  {
    String []fieldNames = (String []) fields;
    Map<Object,Object> map = createMap();
      
    int ref = in.addRef(map);

    for (int i = 0; i < fieldNames.length; i++) {
      String name = fieldNames[i];

      map.put(name, in.readObject());
    }

    return map;
  }

  private Map createMap()
    throws IOException
  {
    
    if (_type == null)
      return new HashMap();
    else if (_type.equals(Map.class))
      return new HashMap();
    else if (_type.equals(SortedMap.class))
      return new TreeMap();
    else {
      try {
        return (Map) _ctor.newInstance();
      } catch (Exception e) {
        throw new IOExceptionWrapper(e);
      }
    }
  }
}