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/*
 * Copyright (c) 2003 The Visigoth Software Society. All rights
 * reserved.
 *
 * 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 acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the 
 *    project contributors may be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [email protected].
 *
 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software Society.
 *
 * 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 THE VISIGOTH SOFTWARE SOCIETY 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */

package freemarker.template;

import java.io.Serializable;
import java.util.ConcurrentModificationException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

import freemarker.ext.beans.BeansWrapper;

/**
 * 

A simple implementation of the TemplateHashModelEx * interface, using an underlying {@link Map} or {@link SortedMap}.

* *

This class is thread-safe if you don't call the put or remove methods * after you have made the object available for multiple threads. * *

Note:
* As of 2.0, this class is unsynchronized by default. * To obtain a synchronized wrapper, call the {@link #synchronizedWrapper} method.

* * @version $Id: SimpleHash.java,v 1.72.2.2 2006/02/26 18:26:18 revusky Exp $ * @see SimpleSequence * @see SimpleScalar */ public class SimpleHash extends WrappingTemplateModel implements TemplateHashModelEx, Serializable { private Map map; private boolean putFailed; private Map unwrappedMap; /** * Constructs an empty hash that uses the default wrapper set in * {@link WrappingTemplateModel#setDefaultObjectWrapper(ObjectWrapper)}. */ public SimpleHash() { this((ObjectWrapper)null); } /** * Creates a new simple hash with the copy of the underlying map and the * default wrapper set in * {@link WrappingTemplateModel#setDefaultObjectWrapper(ObjectWrapper)}. * @param map The Map to use for the key/value pairs. It makes a copy for * internal use. If the map implements the {@link SortedMap} interface, the * internal copy will be a {@link TreeMap}, otherwise it will be a * {@link HashMap}. */ public SimpleHash(Map map) { this(map, null); } /** * Creates an empty simple hash using the specified object wrapper. * @param wrapper The object wrapper to use to wrap objects into * {@link TemplateModel} instances. If null, the default wrapper set in * {@link WrappingTemplateModel#setDefaultObjectWrapper(ObjectWrapper)} is * used. */ public SimpleHash(ObjectWrapper wrapper) { super(wrapper); map = new HashMap(); } /** * Creates a new simple hash with the copy of the underlying map and * either the default wrapper set in * {@link WrappingTemplateModel#setDefaultObjectWrapper(ObjectWrapper)}, or * the {@link freemarker.ext.beans.BeansWrapper JavaBeans wrapper}. * @param map The Map to use for the key/value pairs. It makes a copy for * internal use. If the map implements the {@link SortedMap} interface, the * internal copy will be a {@link TreeMap}, otherwise it will be a * @param wrapper The object wrapper to use to wrap objects into * {@link TemplateModel} instances. If null, the default wrapper set in * {@link WrappingTemplateModel#setDefaultObjectWrapper(ObjectWrapper)} is * used. */ public SimpleHash(Map map, ObjectWrapper wrapper) { super(wrapper); try { this.map = copyMap(map); } catch (ConcurrentModificationException cme) { //This will occur extremely rarely. //If it does, we just wait 5 ms and try again. If // the ConcurrentModificationException // is thrown again, we just let it bubble up this time. // TODO: Maybe we should log here. try { Thread.sleep(5); } catch (InterruptedException ie) { } synchronized (map) { this.map = copyMap(map); } } } protected Map copyMap(Map map) { if (map instanceof HashMap) { return (Map) ((HashMap) map).clone(); } if (map instanceof SortedMap) { if (map instanceof TreeMap) { return (Map) ((TreeMap) map).clone(); } else { return new TreeMap((SortedMap) map); } } return new HashMap(map); } /** * Adds a key-value entry to the map. * * @param key the name by which the object is * identified in the template. * @param obj the object to store. */ public void put(String key, Object obj) { map.put(key, obj); unwrappedMap = null; } /** * Puts a boolean in the map * * @param key the name by which the resulting TemplateModel * is identified in the template. * @param b the boolean to store. */ public void put(String key, boolean b) { put(key, b ? TemplateBooleanModel.TRUE : TemplateBooleanModel.FALSE); } public TemplateModel get(String key) throws TemplateModelException { Object result = map.get(key); // The key to use for putting -- it is the key that already exists in // the map (either key or charKey below). This way, we'll never put a // new key in the map, avoiding spurious ConcurrentModificationException // from another thread iterating over the map, see bug #1939742 in // SourceForge tracker. final Object putKey; if (result == null) { if(key.length() == 1) { // just check for Character key if this is a single-character string Character charKey = new Character(key.charAt(0)); result = map.get(charKey); if (result == null && !(map.containsKey(key) || map.containsKey(charKey))) { return null; } else { putKey = charKey; } } else if(!map.containsKey(key)) { return null; } else { putKey = key; } } else { putKey = key; } if (result instanceof TemplateModel) { return (TemplateModel) result; } TemplateModel tm = wrap(result); if (!putFailed) { try { map.put(putKey, tm); } catch (Exception e) { // If it's immutable or something, we just keep going. putFailed = true; } } return tm; } /** * Removes the given key from the underlying map. * * @param key the key to be removed */ public void remove(String key) { map.remove(key); } /** * Adds all the key/value entries in the map * @param m the map with the entries to add, the keys are assumed to be strings. */ public void putAll(Map m) { for (Iterator it = m.entrySet().iterator(); it.hasNext();) { Map.Entry entry = (Map.Entry) it.next(); this.put((String) entry.getKey(), entry.getValue()); } } /** * Note that this method creates and returns a deep-copy of the underlying hash used * internally. This could be a gotcha for some people * at some point who want to alter something in the data model, * but we should maintain our immutability semantics (at least using default SimpleXXX wrappers) * for the data model. It will recursively unwrap the stuff in the underlying container. */ public Map toMap() throws TemplateModelException { if (unwrappedMap == null) { Class mapClass = this.map.getClass(); Map m = null; try { m = (Map) mapClass.newInstance(); } catch (Exception e) { throw new TemplateModelException("Error instantiating map of type " + mapClass.getName() + "\n" + e.getMessage()); } // Create a copy to maintain immutability semantics and // Do nested unwrapping of elements if necessary. BeansWrapper bw = BeansWrapper.getDefaultInstance(); for (Iterator it = map.entrySet().iterator(); it.hasNext();) { Map.Entry entry = (Map.Entry) it.next(); Object key = entry.getKey(); Object value = entry.getValue(); if (value instanceof TemplateModel) { value = bw.unwrap((TemplateModel) value); } m.put(key, value); } unwrappedMap=m; } return unwrappedMap; } /** * Convenience method for returning the String value of the * underlying map. */ public String toString() { return map.toString(); } public int size() { return map.size(); } public boolean isEmpty() { return map == null || map.isEmpty(); } public TemplateCollectionModel keys() { return new SimpleCollection(map.keySet(), getObjectWrapper()); } public TemplateCollectionModel values() { return new SimpleCollection(map.values(), getObjectWrapper()); } public SimpleHash synchronizedWrapper() { return new SynchronizedHash(); } private class SynchronizedHash extends SimpleHash { public boolean isEmpty() { synchronized (SimpleHash.this) { return SimpleHash.this.isEmpty(); } } public void put(String key, Object obj) { synchronized (SimpleHash.this) { SimpleHash.this.put(key, obj); } } public TemplateModel get(String key) throws TemplateModelException { synchronized (SimpleHash.this) { return SimpleHash.this.get(key); } } public void remove(String key) { synchronized (SimpleHash.this) { SimpleHash.this.remove(key); } } public int size() { synchronized (SimpleHash.this) { return SimpleHash.this.size(); } } public TemplateCollectionModel keys() { synchronized (SimpleHash.this) { return SimpleHash.this.keys(); } } public TemplateCollectionModel values() { synchronized (SimpleHash.this) { return SimpleHash.this.values(); } } public Map toMap() throws TemplateModelException { synchronized (SimpleHash.this) { return SimpleHash.this.toMap(); } } } }




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