    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.set;
    018
    019import java.util.Comparator;
    020import java.util.Set;
    021import java.util.SortedSet;
    022
    023/**
    024 * Decorates another <code>SortedSet</code> to provide additional behaviour.
    025 * <p>
    026 * Methods are forwarded directly to the decorated set.
    027 *
    028 * @param <E> the type of the elements in the sorted set
    029 * @since 3.0
    030 */
    031public abstract class AbstractSortedSetDecorator<E>
    032        extends AbstractSetDecorator<E>
    033        implements SortedSet<E> {
    034
    035    /** Serialization version */
    036    private static final long serialVersionUID = -3462240946294214398L;
    037
    038    /**
    039     * Constructor only used in deserialization, do not use otherwise.
    040     * @since 3.1
    041     */
    042    protected AbstractSortedSetDecorator() {
    043        super();
    044    }
    045
    046    /**
    047     * Constructor that wraps (not copies).
    048     *
    049     * @param set  the set to decorate, must not be null
    050     * @throws NullPointerException if set is null
    051     */
    052    protected AbstractSortedSetDecorator(final Set<E> set) {
    053        super(set);
    054    }
    055
    056    /**
    057     * Gets the set being decorated.
    058     *
    059     * @return the decorated set
    060     */
    061    @Override
    062    protected SortedSet<E> decorated() {
    063        return (SortedSet<E>) super.decorated();
    064    }
    065
    066    //-----------------------------------------------------------------------
    067    @Override
    068    public SortedSet<E> subSet(final E fromElement, final E toElement) {
    069        return decorated().subSet(fromElement, toElement);
    070    }
    071
    072    @Override
    073    public SortedSet<E> headSet(final E toElement) {
    074        return decorated().headSet(toElement);
    075    }
    076
    077    @Override
    078    public SortedSet<E> tailSet(final E fromElement) {
    079        return decorated().tailSet(fromElement);
    080    }
    081
    082    @Override
    083    public E first() {
    084        return decorated().first();
    085    }
    086
    087    @Override
    088    public E last() {
    089        return decorated().last();
    090    }
    091
    092    @Override
    093    public Comparator<? super E> comparator() {
    094        return decorated().comparator();
    095    }
    096
    097}