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