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 * https://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 *
46 * @since 3.1
47 */
48 protected AbstractOrderedMapDecorator() {
49 }
50
51 /**
52 * Constructor that wraps (not copies).
53 *
54 * @param map The map to decorate, must not be null
55 * @throws NullPointerException if the map is null
56 */
57 public AbstractOrderedMapDecorator(final OrderedMap<K, V> map) {
58 super(map);
59 }
60
61 /**
62 * Gets the map being decorated.
63 *
64 * @return The decorated map
65 */
66 @Override
67 protected OrderedMap<K, V> decorated() {
68 return (OrderedMap<K, V>) super.decorated();
69 }
70
71 @Override
72 public K firstKey() {
73 return decorated().firstKey();
74 }
75
76 @Override
77 public K lastKey() {
78 return decorated().lastKey();
79 }
80
81 @Override
82 public OrderedMapIterator<K, V> mapIterator() {
83 return decorated().mapIterator();
84 }
85
86 @Override
87 public K nextKey(final K key) {
88 return decorated().nextKey(key);
89 }
90
91 @Override
92 public K previousKey(final K key) {
93 return decorated().previousKey(key);
94 }
95
96 }