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.collections.map;
18
19 import java.util.Comparator;
20 import java.util.SortedMap;
21
22 import org.apache.commons.collections.Predicate;
23
24 /**
25 * Decorates another <code>SortedMap </code> 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 * One usage would be to ensure that no null keys are added to the map.
33 * <pre>SortedMap map = PredicatedSortedSet.decorate(new TreeMap(), NotNullPredicate.INSTANCE, null);</pre>
34 * <p>
35 * <strong>Note that PredicatedSortedMap is not synchronized and is not thread-safe.</strong>
36 * If you wish to use this map from multiple threads concurrently, you must use
37 * appropriate synchronization. The simplest approach is to wrap this map
38 * using {@link java.util.Collections#synchronizedSortedMap}. This class may throw
39 * exceptions when accessed by concurrent threads without synchronization.
40 * <p>
41 * This class is Serializable from Commons Collections 3.1.
42 *
43 * @since 3.0
44 * @version $Id: PredicatedSortedMap.java 1429905 2013-01-07 17:15:14Z ggregory $
45 */
46 public class PredicatedSortedMap<K, V> extends PredicatedMap<K, V> implements SortedMap<K, V> {
47
48 /** Serialization version */
49 private static final long serialVersionUID = 3359846175935304332L;
50
51 /**
52 * Factory method to create a predicated (validating) sorted map.
53 * <p>
54 * If there are any elements already in the list being decorated, they
55 * are validated.
56 *
57 * @param <K> the key type
58 * @param <V> the value type
59 * @param map the map to decorate, must not be null
60 * @param keyPredicate the predicate to validate the keys, null means no check
61 * @param valuePredicate the predicate to validate to values, null means no check
62 * @return a new predicated sorted map
63 * @throws IllegalArgumentException if the map is null
64 */
65 public static <K, V> PredicatedSortedMap<K, V> predicatedSortedMap(final SortedMap<K, V> map,
66 final Predicate<? super K> keyPredicate, final Predicate<? super V> valuePredicate) {
67 return new PredicatedSortedMap<K, V>(map, keyPredicate, valuePredicate);
68 }
69
70 //-----------------------------------------------------------------------
71 /**
72 * Constructor that wraps (not copies).
73 *
74 * @param map the map to decorate, must not be null
75 * @param keyPredicate the predicate to validate the keys, null means no check
76 * @param valuePredicate the predicate to validate to values, null means no check
77 * @throws IllegalArgumentException if the map is null
78 */
79 protected PredicatedSortedMap(final SortedMap<K, V> map, final Predicate<? super K> keyPredicate,
80 final Predicate<? super V> valuePredicate) {
81 super(map, keyPredicate, valuePredicate);
82 }
83
84 //-----------------------------------------------------------------------
85 /**
86 * Gets the map being decorated.
87 *
88 * @return the decorated map
89 */
90 protected SortedMap<K, V> getSortedMap() {
91 return (SortedMap<K, V>) map;
92 }
93
94 //-----------------------------------------------------------------------
95 public K firstKey() {
96 return getSortedMap().firstKey();
97 }
98
99 public K lastKey() {
100 return getSortedMap().lastKey();
101 }
102
103 public Comparator<? super K> comparator() {
104 return getSortedMap().comparator();
105 }
106
107 public SortedMap<K, V> subMap(final K fromKey, final K toKey) {
108 final SortedMap<K, V> map = getSortedMap().subMap(fromKey, toKey);
109 return new PredicatedSortedMap<K, V>(map, keyPredicate, valuePredicate);
110 }
111
112 public SortedMap<K, V> headMap(final K toKey) {
113 final SortedMap<K, V> map = getSortedMap().headMap(toKey);
114 return new PredicatedSortedMap<K, V>(map, keyPredicate, valuePredicate);
115 }
116
117 public SortedMap<K, V> tailMap(final K fromKey) {
118 final SortedMap<K, V> map = getSortedMap().tailMap(fromKey);
119 return new PredicatedSortedMap<K, V>(map, keyPredicate, valuePredicate);
120 }
121
122 }