001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.collections.map;
018
019 import java.util.Collection;
020 import java.util.Map;
021 import java.util.Set;
022
023 /**
024 * Provides a base decorator that enables additional functionality to be added
025 * to a Map via decoration.
026 * <p>
027 * Methods are forwarded directly to the decorated map.
028 * <p>
029 * This implementation does not perform any special processing with
030 * {@link #entrySet()}, {@link #keySet()} or {@link #values()}. Instead
031 * it simply returns the set/collection from the wrapped map. This may be
032 * undesirable, for example if you are trying to write a validating
033 * implementation it would provide a loophole around the validation.
034 * But, you might want that loophole, so this class is kept simple.
035 *
036 * @since Commons Collections 3.0
037 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
038 *
039 * @author Daniel Rall
040 * @author Stephen Colebourne
041 */
042 public abstract class AbstractMapDecorator implements Map {
043
044 /** The map to decorate */
045 protected transient Map map;
046
047 /**
048 * Constructor only used in deserialization, do not use otherwise.
049 * @since Commons Collections 3.1
050 */
051 protected AbstractMapDecorator() {
052 super();
053 }
054
055 /**
056 * Constructor that wraps (not copies).
057 *
058 * @param map the map to decorate, must not be null
059 * @throws IllegalArgumentException if the collection is null
060 */
061 public AbstractMapDecorator(Map map) {
062 if (map == null) {
063 throw new IllegalArgumentException("Map must not be null");
064 }
065 this.map = map;
066 }
067
068 /**
069 * Gets the map being decorated.
070 *
071 * @return the decorated map
072 */
073 protected Map getMap() {
074 return map;
075 }
076
077 //-----------------------------------------------------------------------
078 public void clear() {
079 map.clear();
080 }
081
082 public boolean containsKey(Object key) {
083 return map.containsKey(key);
084 }
085
086 public boolean containsValue(Object value) {
087 return map.containsValue(value);
088 }
089
090 public Set entrySet() {
091 return map.entrySet();
092 }
093
094 public Object get(Object key) {
095 return map.get(key);
096 }
097
098 public boolean isEmpty() {
099 return map.isEmpty();
100 }
101
102 public Set keySet() {
103 return map.keySet();
104 }
105
106 public Object put(Object key, Object value) {
107 return map.put(key, value);
108 }
109
110 public void putAll(Map mapToCopy) {
111 map.putAll(mapToCopy);
112 }
113
114 public Object remove(Object key) {
115 return map.remove(key);
116 }
117
118 public int size() {
119 return map.size();
120 }
121
122 public Collection values() {
123 return map.values();
124 }
125
126 public boolean equals(Object object) {
127 if (object == this) {
128 return true;
129 }
130 return map.equals(object);
131 }
132
133 public int hashCode() {
134 return map.hashCode();
135 }
136
137 public String toString() {
138 return map.toString();
139 }
140
141 }