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    1   /*
    2    * Copyright (c) 2003 The Visigoth Software Society. All rights
    3    * reserved.
    4    *
    5    * Redistribution and use in source and binary forms, with or without
    6    * modification, are permitted provided that the following conditions
    7    * are met:
    8    *
    9    * 1. Redistributions of source code must retain the above copyright
   10    *    notice, this list of conditions and the following disclaimer.
   11    *
   12    * 2. Redistributions in binary form must reproduce the above copyright
   13    *    notice, this list of conditions and the following disclaimer in
   14    *    the documentation and/or other materials provided with the
   15    *    distribution.
   16    *
   17    * 3. The end-user documentation included with the redistribution, if
   18    *    any, must include the following acknowledgement:
   19    *       "This product includes software developed by the
   20    *        Visigoth Software Society (http://www.visigoths.org/)."
   21    *    Alternately, this acknowledgement may appear in the software itself,
   22    *    if and wherever such third-party acknowledgements normally appear.
   23    *
   24    * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the 
   25    *    project contributors may be used to endorse or promote products derived
   26    *    from this software without prior written permission. For written
   27    *    permission, please contact visigoths@visigoths.org.
   28    *
   29    * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
   30    *    nor may "FreeMarker" or "Visigoth" appear in their names
   31    *    without prior written permission of the Visigoth Software Society.
   32    *
   33    * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   34    * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   35    * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   36    * DISCLAIMED.  IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
   37    * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   38    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   39    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   40    * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   41    * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   42    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   43    * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   44    * SUCH DAMAGE.
   45    * ====================================================================
   46    *
   47    * This software consists of voluntary contributions made by many
   48    * individuals on behalf of the Visigoth Software Society. For more
   49    * information on the Visigoth Software Society, please see
   50    * http://www.visigoths.org/
   51    */
   52   
   53   package freemarker.ext.beans;
   54   
   55   import java.util.List;
   56   import java.util.Map;
   57   import java.util.Set;
   58   
   59   import freemarker.ext.util.ModelFactory;
   60   import freemarker.template.ObjectWrapper;
   61   import freemarker.template.TemplateMethodModelEx;
   62   import freemarker.template.TemplateModel;
   63   import freemarker.template.TemplateModelException;
   64   
   65   /**
   66    * <p>A special case of {@link BeanModel} that adds implementation
   67    * for {@link TemplateMethodModelEx} on map objects that is a shortcut for the
   68    * <tt>Map.get()</tt> method. Note that if the passed argument itself is a
   69    * reflection-wrapper model, then the map lookup will be performed using the
   70    * wrapped object as the key. Note that you can call <tt>get()</tt> using the
   71    * <tt>map.key</tt> syntax inherited from {@link BeanModel} as well, 
   72    * however in that case the key is always a string.</p>
   73    * <p>The class itself does not implement the {@link freemarker.template.TemplateCollectionModel}.
   74    * You can, however use <tt>map.entrySet()</tt>, <tt>map.keySet()</tt>, or
   75    * <tt>map.values()</tt> to obtain {@link freemarker.template.TemplateCollectionModel} instances for 
   76    * various aspects of the map.</p>
   77    * @author Attila Szegedi
   78    * @version $Id: MapModel.java,v 1.26.2.3 2006/02/26 18:26:37 revusky Exp $
   79    */
   80   public class MapModel
   81   extends
   82       StringModel
   83   implements
   84       TemplateMethodModelEx
   85   {
   86       static final ModelFactory FACTORY =
   87           new ModelFactory()
   88           {
   89               public TemplateModel create(Object object, ObjectWrapper wrapper)
   90               {
   91                   return new MapModel((Map)object, (BeansWrapper)wrapper);
   92               }
   93           };
   94   
   95       /**
   96        * Creates a new model that wraps the specified map object.
   97        * @param map the map object to wrap into a model.
   98        * @param wrapper the {@link BeansWrapper} associated with this model.
   99        * Every model has to have an associated {@link BeansWrapper} instance. The
  100        * model gains many attributes from its wrapper, including the caching 
  101        * behavior, method exposure level, method-over-item shadowing policy etc.
  102        */
  103       public MapModel(Map map, BeansWrapper wrapper)
  104       {
  105           super(map, wrapper);
  106       }
  107   
  108       /**
  109        * The first argument is used as a key to call the map's <tt>get</tt> method.
  110        */
  111       public Object exec(List arguments)
  112       throws
  113           TemplateModelException
  114       {
  115           Object key = unwrap((TemplateModel)arguments.get(0));
  116           return wrap(((Map)object).get(key));
  117       }
  118   
  119       /**
  120        * Overridden to invoke the generic get method by casting to Map instead of 
  121        * through reflection - should yield better performance.
  122        */
  123       protected TemplateModel invokeGenericGet(Map keyMap, Class clazz, String key)
  124       throws TemplateModelException
  125       {
  126   		Map map = (Map) object;
  127   		Object val = map.get(key);
  128   		if (val == null && key.length()==1) {
  129   			// just check for Character key if this is a single-character string
  130               try{
  131                   val = map.get(new Character(key.charAt(0)));
  132               } catch (Exception e) {}
  133           }
  134           return wrap(val);
  135       }
  136   
  137       public boolean isEmpty()
  138       {
  139           return ((Map)object).isEmpty() && super.isEmpty();
  140       }
  141   
  142       public int size()
  143       {
  144           return keySet().size();
  145       }
  146   
  147       protected Set keySet()
  148       {
  149           Set set = super.keySet();
  150           set.addAll(((Map)object).keySet());
  151           return set;
  152       }
  153   }

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