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.keyvalue; 018 019import java.util.Map; 020 021import org.apache.commons.collections4.KeyValue; 022 023/** 024 * Provides a base decorator that allows additional functionality to be 025 * added to a {@link java.util.Map.Entry Map.Entry}. 026 * 027 * @param <K> the type of keys 028 * @param <V> the type of mapped values 029 * @since 3.0 030 */ 031public abstract class AbstractMapEntryDecorator<K, V> implements Map.Entry<K, V>, KeyValue<K, V> { 032 033 /** The <code>Map.Entry</code> to decorate */ 034 private final Map.Entry<K, V> entry; 035 036 /** 037 * Constructor that wraps (not copies). 038 * 039 * @param entry the <code>Map.Entry</code> to decorate, must not be null 040 * @throws NullPointerException if the collection is null 041 */ 042 public AbstractMapEntryDecorator(final Map.Entry<K, V> entry) { 043 if (entry == null) { 044 throw new NullPointerException("Map Entry must not be null."); 045 } 046 this.entry = entry; 047 } 048 049 /** 050 * Gets the map being decorated. 051 * 052 * @return the decorated map 053 */ 054 protected Map.Entry<K, V> getMapEntry() { 055 return entry; 056 } 057 058 //----------------------------------------------------------------------- 059 060 @Override 061 public K getKey() { 062 return entry.getKey(); 063 } 064 065 @Override 066 public V getValue() { 067 return entry.getValue(); 068 } 069 070 @Override 071 public V setValue(final V object) { 072 return entry.setValue(object); 073 } 074 075 @Override 076 public boolean equals(final Object object) { 077 if (object == this) { 078 return true; 079 } 080 return entry.equals(object); 081 } 082 083 @Override 084 public int hashCode() { 085 return entry.hashCode(); 086 } 087 088 @Override 089 public String toString() { 090 return entry.toString(); 091 } 092 093}