    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}