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</code> 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    /**
073     * Constructor that wraps (not copies).
074     * <p>
075     * If there are any elements already in the set being decorated, they
076     * are validated.
077     *
078     * @param set  the set to decorate, must not be null
079     * @param predicate  the predicate to use for validation, must not be null
080     * @throws NullPointerException if set or predicate is null
081     * @throws IllegalArgumentException if the set contains invalid elements
082     */
083    protected PredicatedSortedSet(final SortedSet<E> set, final Predicate<? super E> predicate) {
084        super(set, predicate);
085    }
086
087    /**
088     * Gets the sorted set being decorated.
089     *
090     * @return the decorated sorted set
091     */
092    @Override
093    protected SortedSet<E> decorated() {
094        return (SortedSet<E>) super.decorated();
095    }
096
097    //-----------------------------------------------------------------------
098    @Override
099    public Comparator<? super E> comparator() {
100        return decorated().comparator();
101    }
102
103    @Override
104    public E first() {
105        return decorated().first();
106    }
107
108    @Override
109    public E last() {
110        return decorated().last();
111    }
112
113    @Override
114    public SortedSet<E> subSet(final E fromElement, final E toElement) {
115        final SortedSet<E> sub = decorated().subSet(fromElement, toElement);
116        return new PredicatedSortedSet<>(sub, predicate);
117    }
118
119    @Override
120    public SortedSet<E> headSet(final E toElement) {
121        final SortedSet<E> head = decorated().headSet(toElement);
122        return new PredicatedSortedSet<>(head, predicate);
123    }
124
125    @Override
126    public SortedSet<E> tailSet(final E fromElement) {
127        final SortedSet<E> tail = decorated().tailSet(fromElement);
128        return new PredicatedSortedSet<>(tail, predicate);
129    }
130
131}