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.SortedSet;
021
022import org.apache.commons.collections4.Predicate;
023
024/**
025 * Decorates another {@code SortedSet} to validate that all additions
026 * match a specified predicate.
027 * <p>
028 * This set exists to provide validation for the decorated set.
029 * It is normally created to decorate an empty set.
030 * If an object cannot be added to the set, an IllegalArgumentException is thrown.
031 * </p>
032 * <p>
033 * One usage would be to ensure that no null entries are added to the set.
034 * </p>
035 * <pre>
036 * SortedSet set =
037 *   PredicatedSortedSet.predicatedSortedSet(new TreeSet(),
038 *                                           NotNullPredicate.notNullPredicate());
039 * </pre>
040 * <p>
041 * This class is Serializable from Commons Collections 3.1.
042 * </p>
043 *
044 * @param <E> the type of the elements in this set
045 * @since 3.0
046 */
047public class PredicatedSortedSet<E> extends PredicatedSet<E> implements SortedSet<E> {
048
049    /** Serialization version */
050    private static final long serialVersionUID = -9110948148132275052L;
051
052    /**
053     * Factory method to create a predicated (validating) sorted set.
054     * <p>
055     * If there are any elements already in the set being decorated, they
056     * are validated.
057     *
058     * @param <E> the element type
059     * @param set  the set to decorate, must not be null
060     * @param predicate  the predicate to use for validation, must not be null
061     * @return a new predicated sorted set.
062     * @throws NullPointerException if set or predicate is null
063     * @throws IllegalArgumentException if the set contains invalid elements
064     * @since 4.0
065     */
066    public static <E> PredicatedSortedSet<E> predicatedSortedSet(final SortedSet<E> set,
067                                                                 final Predicate<? super E> predicate) {
068        return new PredicatedSortedSet<>(set, predicate);
069    }
070
071    /**
072     * Constructor that wraps (not copies).
073     * <p>
074     * If there are any elements already in the set being decorated, they
075     * are validated.
076     *
077     * @param set  the set to decorate, must not be null
078     * @param predicate  the predicate to use for validation, must not be null
079     * @throws NullPointerException if set or predicate is null
080     * @throws IllegalArgumentException if the set contains invalid elements
081     */
082    protected PredicatedSortedSet(final SortedSet<E> set, final Predicate<? super E> predicate) {
083        super(set, predicate);
084    }
085
086    @Override
087    public Comparator<? super E> comparator() {
088        return decorated().comparator();
089    }
090
091    /**
092     * Gets the sorted set being decorated.
093     *
094     * @return the decorated sorted set
095     */
096    @Override
097    protected SortedSet<E> decorated() {
098        return (SortedSet<E>) super.decorated();
099    }
100
101    @Override
102    public E first() {
103        return decorated().first();
104    }
105
106    @Override
107    public SortedSet<E> headSet(final E toElement) {
108        final SortedSet<E> head = decorated().headSet(toElement);
109        return new PredicatedSortedSet<>(head, predicate);
110    }
111
112    @Override
113    public E last() {
114        return decorated().last();
115    }
116
117    @Override
118    public SortedSet<E> subSet(final E fromElement, final E toElement) {
119        final SortedSet<E> sub = decorated().subSet(fromElement, toElement);
120        return new PredicatedSortedSet<>(sub, predicate);
121    }
122
123    @Override
124    public SortedSet<E> tailSet(final E fromElement) {
125        final SortedSet<E> tail = decorated().tailSet(fromElement);
126        return new PredicatedSortedSet<>(tail, predicate);
127    }
128
129}