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 *      https://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 org.apache.commons.collections4.OrderedMap;
020import org.apache.commons.collections4.OrderedMapIterator;
021
022/**
023 * Provides a base decorator that enables additional functionality to be added
024 * to an OrderedMap via decoration.
025 * <p>
026 * Methods are forwarded directly to the decorated map.
027 * </p>
028 * <p>
029 * This implementation does not perform any special processing with the map views.
030 * Instead it simply returns the set/collection from the wrapped map. This may be
031 * undesirable, for example if you are trying to write a validating implementation
032 * it would provide a loophole around the validation.
033 * But, you might want that loophole, so this class is kept simple.
034 * </p>
035 *
036 * @param <K> The type of the keys in this map
037 * @param <V> The type of the values in this map
038 * @since 3.0
039 */
040public abstract class AbstractOrderedMapDecorator<K, V> extends AbstractMapDecorator<K, V>
041        implements OrderedMap<K, V> {
042
043    /**
044     * Constructor only used in deserialization, do not use otherwise.
045     *
046     * @since 3.1
047     */
048    protected AbstractOrderedMapDecorator() {
049    }
050
051    /**
052     * Constructor that wraps (not copies).
053     *
054     * @param map  The map to decorate, must not be null
055     * @throws NullPointerException if the map is null
056     */
057    public AbstractOrderedMapDecorator(final OrderedMap<K, V> map) {
058        super(map);
059    }
060
061    /**
062     * Gets the map being decorated.
063     *
064     * @return The decorated map
065     */
066    @Override
067    protected OrderedMap<K, V> decorated() {
068        return (OrderedMap<K, V>) super.decorated();
069    }
070
071    @Override
072    public K firstKey() {
073        return decorated().firstKey();
074    }
075
076    @Override
077    public K lastKey() {
078        return decorated().lastKey();
079    }
080
081    @Override
082    public OrderedMapIterator<K, V> mapIterator() {
083        return decorated().mapIterator();
084    }
085
086    @Override
087    public K nextKey(final K key) {
088        return decorated().nextKey(key);
089    }
090
091    @Override
092    public K previousKey(final K key) {
093        return decorated().previousKey(key);
094    }
095
096}