    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</code> to provide additional behaviour.
    025 * <p>
    026 * Methods are forwarded directly to the decorated bag.
    027 *
    028 * @param <E> the type of elements in this bag
    029 * @since 3.0
    030 */
    031public abstract class AbstractSortedBagDecorator<E>
    032        extends AbstractBagDecorator<E> implements SortedBag<E> {
    033
    034    /** Serialization version */
    035    private static final long serialVersionUID = -8223473624050467718L;
    036
    037    /**
    038     * Constructor only used in deserialization, do not use otherwise.
    039     * @since 3.1
    040     */
    041    protected AbstractSortedBagDecorator() {
    042        super();
    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    /**
    056     * Gets the bag being decorated.
    057     *
    058     * @return the decorated bag
    059     */
    060    @Override
    061    protected SortedBag<E> decorated() {
    062        return (SortedBag<E>) super.decorated();
    063    }
    064
    065    //-----------------------------------------------------------------------
    066
    067    @Override
    068    public E first() {
    069        return decorated().first();
    070    }
    071
    072    @Override
    073    public E last() {
    074        return decorated().last();
    075    }
    076
    077    @Override
    078    public Comparator<? super E> comparator() {
    079        return decorated().comparator();
    080    }
    081
    082}