1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.collections4.map;
18
19 import java.util.Comparator;
20 import java.util.SortedMap;
21
22 import org.apache.commons.collections4.Predicate;
23
24 /**
25 * Decorates another {@code SortedMap} to validate that additions
26 * match a specified predicate.
27 * <p>
28 * This map exists to provide validation for the decorated map.
29 * It is normally created to decorate an empty map.
30 * If an object cannot be added to the map, an IllegalArgumentException is thrown.
31 * </p>
32 * <p>
33 * One usage would be to ensure that no null keys are added to the map.
34 * </p>
35 * <pre>
36 * SortedMap map =
37 * PredicatedSortedMap.predicatedSortedMap(new TreeMap(),
38 * NotNullPredicate.notNullPredicate(),
39 * null);
40 * </pre>
41 * <p>
42 * <strong>Note that PredicatedSortedMap is not synchronized and is not thread-safe.</strong>
43 * If you wish to use this map from multiple threads concurrently, you must use
44 * appropriate synchronization. The simplest approach is to wrap this map
45 * using {@link java.util.Collections#synchronizedSortedMap}. This class may throw
46 * exceptions when accessed by concurrent threads without synchronization.
47 * </p>
48 * <p>
49 * This class is Serializable from Commons Collections 3.1.
50 * </p>
51 *
52 * @param <K> the type of the keys in this map
53 * @param <V> the type of the values in this map
54 * @since 3.0
55 */
56 public class PredicatedSortedMap<K, V> extends PredicatedMap<K, V> implements SortedMap<K, V> {
57
58 /** Serialization version */
59 private static final long serialVersionUID = 3359846175935304332L;
60
61 /**
62 * Factory method to create a predicated (validating) sorted map.
63 * <p>
64 * If there are any elements already in the list being decorated, they
65 * are validated.
66 * </p>
67 *
68 * @param <K> the key type
69 * @param <V> the value type
70 * @param map the map to decorate, must not be null
71 * @param keyPredicate the predicate to validate the keys, null means no check
72 * @param valuePredicate the predicate to validate to values, null means no check
73 * @return a new predicated sorted map
74 * @throws NullPointerException if the map is null
75 * @since 4.0
76 */
77 public static <K, V> PredicatedSortedMap<K, V> predicatedSortedMap(final SortedMap<K, V> map,
78 final Predicate<? super K> keyPredicate, final Predicate<? super V> valuePredicate) {
79 return new PredicatedSortedMap<>(map, keyPredicate, valuePredicate);
80 }
81
82 /**
83 * Constructor that wraps (not copies).
84 *
85 * @param map the map to decorate, must not be null
86 * @param keyPredicate the predicate to validate the keys, null means no check
87 * @param valuePredicate the predicate to validate to values, null means no check
88 * @throws NullPointerException if the map is null
89 */
90 protected PredicatedSortedMap(final SortedMap<K, V> map, final Predicate<? super K> keyPredicate,
91 final Predicate<? super V> valuePredicate) {
92 super(map, keyPredicate, valuePredicate);
93 }
94
95 @Override
96 public Comparator<? super K> comparator() {
97 return getSortedMap().comparator();
98 }
99
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 }