    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}