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 org.apache.commons.collections4.OrderedMap;
20 import org.apache.commons.collections4.OrderedMapIterator;
21
22 /**
23 * Provides a base decorator that enables additional functionality to be added
24 * to an OrderedMap via decoration.
25 * <p>
26 * Methods are forwarded directly to the decorated map.
27 * </p>
28 * <p>
29 * This implementation does not perform any special processing with the map views.
30 * Instead it simply returns the set/collection from the wrapped map. This may be
31 * undesirable, for example if you are trying to write a validating implementation
32 * it would provide a loophole around the validation.
33 * But, you might want that loophole, so this class is kept simple.
34 * </p>
35 *
36 * @param <K> the type of the keys in this map
37 * @param <V> the type of the values in this map
38 * @since 3.0
39 */
40 public abstract class AbstractOrderedMapDecorator<K, V> extends AbstractMapDecorator<K, V>
41 implements OrderedMap<K, V> {
42
43 /**
44 * Constructor only used in deserialization, do not use otherwise.
45 * @since 3.1
46 */
47 protected AbstractOrderedMapDecorator() {
48 }
49
50 /**
51 * Constructor that wraps (not copies).
52 *
53 * @param map the map to decorate, must not be null
54 * @throws NullPointerException if the map is null
55 */
56 public AbstractOrderedMapDecorator(final OrderedMap<K, V> map) {
57 super(map);
58 }
59
60 /**
61 * Gets the map being decorated.
62 *
63 * @return the decorated map
64 */
65 @Override
66 protected OrderedMap<K, V> decorated() {
67 return (OrderedMap<K, V>) super.decorated();
68 }
69
70 @Override
71 public K firstKey() {
72 return decorated().firstKey();
73 }
74
75 @Override
76 public K lastKey() {
77 return decorated().lastKey();
78 }
79
80 @Override
81 public OrderedMapIterator<K, V> mapIterator() {
82 return decorated().mapIterator();
83 }
84
85 @Override
86 public K nextKey(final K key) {
87 return decorated().nextKey(key);
88 }
89
90 @Override
91 public K previousKey(final K key) {
92 return decorated().previousKey(key);
93 }
94
95 }