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