    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 *      https://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.multiset;
    018
    019import java.util.Comparator;
    020
    021import org.apache.commons.collections4.Predicate;
    022import org.apache.commons.collections4.SortedMultiSet;
    023
    024/**
    025 * Decorates another {@link SortedMultiSet} to validate that additions
    026 * match a specified predicate.
    027 * <p>
    028 * This multiset exists to provide validation for the decorated multiset.
    029 * It is normally created to decorate an empty multiset.
    030 * If an object cannot be added to the multiset, an {@link IllegalArgumentException}
    031 * is thrown.
    032 * </p>
    033 * <p>
    034 * One usage would be to ensure that no null entries are added to the multiset.
    035 * </p>
    036 * <pre>
    037 * SortedMultiSet&lt;E&gt; set =
    038 *      PredicatedSortedMultiSet.predicatedSortedMultiSet(new TreeMultiSet&lt;E&gt;(),
    039 *                                                        NotNullPredicate.notNullPredicate());
    040 * </pre>
    041 *
    042 * @param <E> The type held in the multiset
    043 * @since 4.6.0
    044 */
    045public class PredicatedSortedMultiSet<E> extends PredicatedMultiSet<E> implements SortedMultiSet<E> {
    046
    047    /** Serialization version */
    048    private static final long serialVersionUID = 20260705L;
    049
    050    /**
    051     * Factory method to create a predicated (validating) multiset.
    052     * <p>
    053     * If there are any elements already in the multiset being decorated, they
    054     * are validated.
    055     *
    056     * @param <E> The type of the elements in the multiset
    057     * @param multiset  The multiset to decorate, must not be null
    058     * @param predicate  The predicate to use for validation, must not be null
    059     * @return A new predicated SortedMultiSet
    060     * @throws NullPointerException if multiset or predicate is null
    061     * @throws IllegalArgumentException if the multiset contains invalid elements
    062     */
    063    public static <E> PredicatedSortedMultiSet<E> predicatedSortedMultiSet(final SortedMultiSet<E> multiset,
    064                                                                           final Predicate<? super E> predicate) {
    065        return new PredicatedSortedMultiSet<>(multiset, predicate);
    066    }
    067
    068    /**
    069     * Constructor that wraps (not copies).
    070     * <p>
    071     * If there are any elements already in the multiset being decorated, they
    072     * are validated.
    073     * </p>
    074     *
    075     * @param multiset  The multiset to decorate, must not be null
    076     * @param predicate  The predicate to use for validation, must not be null
    077     * @throws NullPointerException if multiset or predicate is null
    078     * @throws IllegalArgumentException if the multiset contains invalid elements
    079     */
    080    protected PredicatedSortedMultiSet(final SortedMultiSet<E> multiset, final Predicate<? super E> predicate) {
    081        super(multiset, predicate);
    082    }
    083
    084    @Override
    085    public Comparator<? super E> comparator() {
    086        return decorated().comparator();
    087    }
    088
    089    /**
    090     * Gets the decorated sorted multiset.
    091     *
    092     * @return The decorated multiset
    093     */
    094    @Override
    095    protected SortedMultiSet<E> decorated() {
    096        return (SortedMultiSet<E>) super.decorated();
    097    }
    098
    099    @Override
    100    public E first() {
    101        return decorated().first();
    102    }
    103
    104    @Override
    105    public E last() {
    106        return decorated().last();
    107    }
    108
    109}