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.Objects; 022import java.util.Set; 023 024/** 025 * Provides a base decorator that enables additional functionality to be added 026 * to a Map via decoration. 027 * <p> 028 * Methods are forwarded directly to the decorated map. 029 * </p> 030 * <p> 031 * This implementation does not perform any special processing with 032 * {@link #entrySet()}, {@link #keySet()} or {@link #values()}. Instead 033 * it simply returns the set/collection from the wrapped map. This may be 034 * undesirable, for example if you are trying to write a validating 035 * implementation it would provide a loophole around the validation. 036 * But, you might want that loophole, so this class is kept simple. 037 * </p> 038 * 039 * @param <K> the type of the keys in the map 040 * @param <V> the type of the values in the map 041 * @since 3.0 042 */ 043public abstract class AbstractMapDecorator<K, V> extends AbstractIterableMap<K, V> { 044 045 /** The map to decorate */ 046 transient Map<K, V> map; 047 048 /** 049 * Constructor only used in deserialization, do not use otherwise. 050 * @since 3.1 051 */ 052 protected AbstractMapDecorator() { 053 } 054 055 /** 056 * Constructor that wraps (not copies). 057 * 058 * @param map the map to decorate, must not be null 059 * @throws NullPointerException if the map is null 060 */ 061 protected AbstractMapDecorator(final Map<K, V> map) { 062 this.map = Objects.requireNonNull(map, "map"); 063 } 064 065 @Override 066 public void clear() { 067 decorated().clear(); 068 } 069 070 @Override 071 public boolean containsKey(final Object key) { 072 return decorated().containsKey(key); 073 } 074 075 @Override 076 public boolean containsValue(final Object value) { 077 return decorated().containsValue(value); 078 } 079 080 /** 081 * Gets the map being decorated. 082 * 083 * @return the decorated map 084 */ 085 protected Map<K, V> decorated() { 086 return map; 087 } 088 089 @Override 090 public Set<Map.Entry<K, V>> entrySet() { 091 return decorated().entrySet(); 092 } 093 094 @Override 095 public boolean equals(final Object object) { 096 if (object == this) { 097 return true; 098 } 099 return decorated().equals(object); 100 } 101 102 @Override 103 public V get(final Object key) { 104 return decorated().get(key); 105 } 106 107 @Override 108 public int hashCode() { 109 return decorated().hashCode(); 110 } 111 112 @Override 113 public boolean isEmpty() { 114 return decorated().isEmpty(); 115 } 116 117 @Override 118 public Set<K> keySet() { 119 return decorated().keySet(); 120 } 121 122 @Override 123 public V put(final K key, final V value) { 124 return decorated().put(key, value); 125 } 126 127 @Override 128 public void putAll(final Map<? extends K, ? extends V> mapToCopy) { 129 decorated().putAll(mapToCopy); 130 } 131 132 @Override 133 public V remove(final Object key) { 134 return decorated().remove(key); 135 } 136 137 @Override 138 public int size() { 139 return decorated().size(); 140 } 141 142 @Override 143 public String toString() { 144 return decorated().toString(); 145 } 146 147 @Override 148 public Collection<V> values() { 149 return decorated().values(); 150 } 151 152}