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