    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.map;
    018
    019import java.util.Comparator;
    020import java.util.SortedMap;
    021
    022import org.apache.commons.collections4.Predicate;
    023
    024/**
    025 * Decorates another <code>SortedMap</code> to validate that additions
    026 * match a specified predicate.
    027 * <p>
    028 * This map exists to provide validation for the decorated map.
    029 * It is normally created to decorate an empty map.
    030 * If an object cannot be added to the map, an IllegalArgumentException is thrown.
    031 * <p>
    032 * One usage would be to ensure that no null keys are added to the map.
    033 * <pre>
    034 *   SortedMap map =
    035 *     PredicatedSortedMap.predicatedSortedMap(new TreeMap(),
    036 *                                             NotNullPredicate.notNullPredicate(),
    037 *                                             null);
    038 * </pre>
    039 * <p>
    040 * <strong>Note that PredicatedSortedMap is not synchronized and is not thread-safe.</strong>
    041 * If you wish to use this map from multiple threads concurrently, you must use
    042 * appropriate synchronization. The simplest approach is to wrap this map
    043 * using {@link java.util.Collections#synchronizedSortedMap}. This class may throw
    044 * exceptions when accessed by concurrent threads without synchronization.
    045 * <p>
    046 * This class is Serializable from Commons Collections 3.1.
    047 *
    048 * @param <K> the type of the keys in this map
    049 * @param <V> the type of the values in this map
    050 * @since 3.0
    051 */
    052public class PredicatedSortedMap<K, V> extends PredicatedMap<K, V> implements SortedMap<K, V> {
    053
    054    /** Serialization version */
    055    private static final long serialVersionUID = 3359846175935304332L;
    056
    057    /**
    058     * Factory method to create a predicated (validating) sorted map.
    059     * <p>
    060     * If there are any elements already in the list being decorated, they
    061     * are validated.
    062     *
    063     * @param <K>  the key type
    064     * @param <V>  the value type
    065     * @param map  the map to decorate, must not be null
    066     * @param keyPredicate  the predicate to validate the keys, null means no check
    067     * @param valuePredicate  the predicate to validate to values, null means no check
    068     * @return a new predicated sorted map
    069     * @throws NullPointerException if the map is null
    070     * @since 4.0
    071     */
    072    public static <K, V> PredicatedSortedMap<K, V> predicatedSortedMap(final SortedMap<K, V> map,
    073            final Predicate<? super K> keyPredicate, final Predicate<? super V> valuePredicate) {
    074        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
    075    }
    076
    077    //-----------------------------------------------------------------------
    078    /**
    079     * Constructor that wraps (not copies).
    080     *
    081     * @param map  the map to decorate, must not be null
    082     * @param keyPredicate  the predicate to validate the keys, null means no check
    083     * @param valuePredicate  the predicate to validate to values, null means no check
    084     * @throws NullPointerException if the map is null
    085     */
    086    protected PredicatedSortedMap(final SortedMap<K, V> map, final Predicate<? super K> keyPredicate,
    087            final Predicate<? super V> valuePredicate) {
    088        super(map, keyPredicate, valuePredicate);
    089    }
    090
    091    //-----------------------------------------------------------------------
    092    /**
    093     * Gets the map being decorated.
    094     *
    095     * @return the decorated map
    096     */
    097    protected SortedMap<K, V> getSortedMap() {
    098        return (SortedMap<K, V>) map;
    099    }
    100
    101    //-----------------------------------------------------------------------
    102    @Override
    103    public K firstKey() {
    104        return getSortedMap().firstKey();
    105    }
    106
    107    @Override
    108    public K lastKey() {
    109        return getSortedMap().lastKey();
    110    }
    111
    112    @Override
    113    public Comparator<? super K> comparator() {
    114        return getSortedMap().comparator();
    115    }
    116
    117    @Override
    118    public SortedMap<K, V> subMap(final K fromKey, final K toKey) {
    119        final SortedMap<K, V> map = getSortedMap().subMap(fromKey, toKey);
    120        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
    121    }
    122
    123    @Override
    124    public SortedMap<K, V> headMap(final K toKey) {
    125        final SortedMap<K, V> map = getSortedMap().headMap(toKey);
    126        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
    127    }
    128
    129    @Override
    130    public SortedMap<K, V> tailMap(final K fromKey) {
    131        final SortedMap<K, V> map = getSortedMap().tailMap(fromKey);
    132        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
    133    }
    134
    135}