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 * @since 3.0
028 * @version $Id: AbstractMapEntryDecorator.html 972421 2015-11-14 20:00:04Z tn $
029 */
030public abstract class AbstractMapEntryDecorator<K, V> implements Map.Entry<K, V>, KeyValue<K, V> {
031
032    /** The <code>Map.Entry</code> to decorate */
033    private final Map.Entry<K, V> entry;
034
035    /**
036     * Constructor that wraps (not copies).
037     *
038     * @param entry  the <code>Map.Entry</code> to decorate, must not be null
039     * @throws IllegalArgumentException if the collection is null
040     */
041    public AbstractMapEntryDecorator(final Map.Entry<K, V> entry) {
042        if (entry == null) {
043            throw new IllegalArgumentException("Map Entry must not be null");
044        }
045        this.entry = entry;
046    }
047
048    /**
049     * Gets the map being decorated.
050     *
051     * @return the decorated map
052     */
053    protected Map.Entry<K, V> getMapEntry() {
054        return entry;
055    }
056
057    //-----------------------------------------------------------------------
058
059    public K getKey() {
060        return entry.getKey();
061    }
062
063    public V getValue() {
064        return entry.getValue();
065    }
066
067    public V setValue(final V object) {
068        return entry.setValue(object);
069    }
070
071    @Override
072    public boolean equals(final Object object) {
073        if (object == this) {
074            return true;
075        }
076        return entry.equals(object);
077    }
078
079    @Override
080    public int hashCode() {
081        return entry.hashCode();
082    }
083
084    @Override
085    public String toString() {
086        return entry.toString();
087    }
088
089}