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} 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 * <p>
033 * One usage would be to ensure that no null keys are added to the map.
034 * </p>
035 * <pre>
036 *   SortedMap map =
037 *     PredicatedSortedMap.predicatedSortedMap(new TreeMap(),
038 *                                             NotNullPredicate.notNullPredicate(),
039 *                                             null);
040 * </pre>
041 * <p>
042 * <strong>Note that PredicatedSortedMap is not synchronized and is not thread-safe.</strong>
043 * If you wish to use this map from multiple threads concurrently, you must use
044 * appropriate synchronization. The simplest approach is to wrap this map
045 * using {@link java.util.Collections#synchronizedSortedMap}. This class may throw
046 * exceptions when accessed by concurrent threads without synchronization.
047 * </p>
048 * <p>
049 * This class is Serializable from Commons Collections 3.1.
050 * </p>
051 *
052 * @param <K> the type of the keys in this map
053 * @param <V> the type of the values in this map
054 * @since 3.0
055 */
056public class PredicatedSortedMap<K, V> extends PredicatedMap<K, V> implements SortedMap<K, V> {
057
058    /** Serialization version */
059    private static final long serialVersionUID = 3359846175935304332L;
060
061    /**
062     * Factory method to create a predicated (validating) sorted map.
063     * <p>
064     * If there are any elements already in the list being decorated, they
065     * are validated.
066     * </p>
067     *
068     * @param <K>  the key type
069     * @param <V>  the value type
070     * @param map  the map to decorate, must not be null
071     * @param keyPredicate  the predicate to validate the keys, null means no check
072     * @param valuePredicate  the predicate to validate to values, null means no check
073     * @return a new predicated sorted map
074     * @throws NullPointerException if the map is null
075     * @since 4.0
076     */
077    public static <K, V> PredicatedSortedMap<K, V> predicatedSortedMap(final SortedMap<K, V> map,
078            final Predicate<? super K> keyPredicate, final Predicate<? super V> valuePredicate) {
079        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
080    }
081
082    /**
083     * Constructor that wraps (not copies).
084     *
085     * @param map  the map to decorate, must not be null
086     * @param keyPredicate  the predicate to validate the keys, null means no check
087     * @param valuePredicate  the predicate to validate to values, null means no check
088     * @throws NullPointerException if the map is null
089     */
090    protected PredicatedSortedMap(final SortedMap<K, V> map, final Predicate<? super K> keyPredicate,
091            final Predicate<? super V> valuePredicate) {
092        super(map, keyPredicate, valuePredicate);
093    }
094
095    @Override
096    public Comparator<? super K> comparator() {
097        return getSortedMap().comparator();
098    }
099
100    @Override
101    public K firstKey() {
102        return getSortedMap().firstKey();
103    }
104
105    /**
106     * Gets the map being decorated.
107     *
108     * @return the decorated map
109     */
110    protected SortedMap<K, V> getSortedMap() {
111        return (SortedMap<K, V>) map;
112    }
113
114    @Override
115    public SortedMap<K, V> headMap(final K toKey) {
116        final SortedMap<K, V> map = getSortedMap().headMap(toKey);
117        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
118    }
119
120    @Override
121    public K lastKey() {
122        return getSortedMap().lastKey();
123    }
124
125    @Override
126    public SortedMap<K, V> subMap(final K fromKey, final K toKey) {
127        final SortedMap<K, V> map = getSortedMap().subMap(fromKey, toKey);
128        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
129    }
130
131    @Override
132    public SortedMap<K, V> tailMap(final K fromKey) {
133        final SortedMap<K, V> map = getSortedMap().tailMap(fromKey);
134        return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
135    }
136
137}