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.bag;
018
019import java.util.Comparator;
020
021import org.apache.commons.collections4.SortedBag;
022
023/**
024 * Decorates another {@code SortedBag} to provide additional behavior.
025 * <p>
026 * Methods are forwarded directly to the decorated bag.
027 * </p>
028 *
029 * @param <E> the type of elements in this bag
030 * @since 3.0
031 */
032public abstract class AbstractSortedBagDecorator<E>
033        extends AbstractBagDecorator<E> implements SortedBag<E> {
034
035    /** Serialization version */
036    private static final long serialVersionUID = -8223473624050467718L;
037
038    /**
039     * Constructor only used in deserialization, do not use otherwise.
040     * @since 3.1
041     */
042    protected AbstractSortedBagDecorator() {
043    }
044
045    /**
046     * Constructor that wraps (not copies).
047     *
048     * @param bag  the bag to decorate, must not be null
049     * @throws NullPointerException if bag is null
050     */
051    protected AbstractSortedBagDecorator(final SortedBag<E> bag) {
052        super(bag);
053    }
054
055    @Override
056    public Comparator<? super E> comparator() {
057        return decorated().comparator();
058    }
059
060    /**
061     * Gets the bag being decorated.
062     *
063     * @return the decorated bag
064     */
065    @Override
066    protected SortedBag<E> decorated() {
067        return (SortedBag<E>) super.decorated();
068    }
069
070    @Override
071    public E first() {
072        return decorated().first();
073    }
074
075    @Override
076    public E last() {
077        return decorated().last();
078    }
079
080}