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 */ 017package org.apache.commons.collections4.map; 018 019import java.util.Collection; 020import java.util.Map; 021import 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 * @param <K> the type of the keys in the map 037 * @param <V> the type of the values in the map 038 * @since 3.0 039 */ 040public abstract class AbstractMapDecorator<K, V> extends AbstractIterableMap<K, V> { 041 042 /** The map to decorate */ 043 transient Map<K, V> map; 044 045 /** 046 * Constructor only used in deserialization, do not use otherwise. 047 * @since 3.1 048 */ 049 protected AbstractMapDecorator() { 050 super(); 051 } 052 053 /** 054 * Constructor that wraps (not copies). 055 * 056 * @param map the map to decorate, must not be null 057 * @throws NullPointerException if the map is null 058 */ 059 protected AbstractMapDecorator(final Map<K, V> map) { 060 if (map == null) { 061 throw new NullPointerException("Map must not be null."); 062 } 063 this.map = map; 064 } 065 066 /** 067 * Gets the map being decorated. 068 * 069 * @return the decorated map 070 */ 071 protected Map<K, V> decorated() { 072 return map; 073 } 074 075 //----------------------------------------------------------------------- 076 @Override 077 public void clear() { 078 decorated().clear(); 079 } 080 081 @Override 082 public boolean containsKey(final Object key) { 083 return decorated().containsKey(key); 084 } 085 086 @Override 087 public boolean containsValue(final Object value) { 088 return decorated().containsValue(value); 089 } 090 091 @Override 092 public Set<Map.Entry<K, V>> entrySet() { 093 return decorated().entrySet(); 094 } 095 096 @Override 097 public V get(final Object key) { 098 return decorated().get(key); 099 } 100 101 @Override 102 public boolean isEmpty() { 103 return decorated().isEmpty(); 104 } 105 106 @Override 107 public Set<K> keySet() { 108 return decorated().keySet(); 109 } 110 111 @Override 112 public V put(final K key, final V value) { 113 return decorated().put(key, value); 114 } 115 116 @Override 117 public void putAll(final Map<? extends K, ? extends V> mapToCopy) { 118 decorated().putAll(mapToCopy); 119 } 120 121 @Override 122 public V remove(final Object key) { 123 return decorated().remove(key); 124 } 125 126 @Override 127 public int size() { 128 return decorated().size(); 129 } 130 131 @Override 132 public Collection<V> values() { 133 return decorated().values(); 134 } 135 136 @Override 137 public boolean equals(final Object object) { 138 if (object == this) { 139 return true; 140 } 141 return decorated().equals(object); 142 } 143 144 @Override 145 public int hashCode() { 146 return decorated().hashCode(); 147 } 148 149 @Override 150 public String toString() { 151 return decorated().toString(); 152 } 153 154}