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.set;
18
19 import java.util.Comparator;
20 import java.util.Set;
21 import java.util.SortedSet;
22
23 /**
24 * Decorates another <code>SortedSet</code> to provide additional behaviour.
25 * <p>
26 * Methods are forwarded directly to the decorated set.
27 *
28 * @since Commons Collections 3.0
29 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
30 *
31 * @author Stephen Colebourne
32 */
33 public abstract class AbstractSortedSetDecorator extends AbstractSetDecorator implements SortedSet {
34
35 /**
36 * Constructor only used in deserialization, do not use otherwise.
37 * @since Commons Collections 3.1
38 */
39 protected AbstractSortedSetDecorator() {
40 super();
41 }
42
43 /**
44 * Constructor that wraps (not copies).
45 *
46 * @param set the set to decorate, must not be null
47 * @throws IllegalArgumentException if set is null
48 */
49 protected AbstractSortedSetDecorator(Set set) {
50 super(set);
51 }
52
53 /**
54 * Gets the sorted set being decorated.
55 *
56 * @return the decorated set
57 */
58 protected SortedSet getSortedSet() {
59 return (SortedSet) getCollection();
60 }
61
62 //-----------------------------------------------------------------------
63 public SortedSet subSet(Object fromElement, Object toElement) {
64 return getSortedSet().subSet(fromElement, toElement);
65 }
66
67 public SortedSet headSet(Object toElement) {
68 return getSortedSet().headSet(toElement);
69 }
70
71 public SortedSet tailSet(Object fromElement) {
72 return getSortedSet().tailSet(fromElement);
73 }
74
75 public Object first() {
76 return getSortedSet().first();
77 }
78
79 public Object last() {
80 return getSortedSet().last();
81 }
82
83 public Comparator comparator() {
84 return getSortedSet().comparator();
85 }
86
87 }