    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 * <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     * @since 3.1
    046     */
    047    protected AbstractOrderedMapDecorator() {
    048        super();
    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    //-----------------------------------------------------------------------
    072    @Override
    073    public K firstKey() {
    074        return decorated().firstKey();
    075    }
    076
    077    @Override
    078    public K lastKey() {
    079        return decorated().lastKey();
    080    }
    081
    082    @Override
    083    public K nextKey(final K key) {
    084        return decorated().nextKey(key);
    085    }
    086
    087    @Override
    088    public K previousKey(final K key) {
    089        return decorated().previousKey(key);
    090    }
    091
    092    @Override
    093    public OrderedMapIterator<K, V> mapIterator() {
    094        return decorated().mapIterator();
    095    }
    096
    097}