01: /*
02: * Copyright 2003-2004 The Apache Software Foundation
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16: package org.apache.commons.collections.set;
17:
18: import java.util.Comparator;
19: import java.util.Set;
20: import java.util.SortedSet;
21:
22: /**
23: * Decorates another <code>SortedSet</code> to provide additional behaviour.
24: * <p>
25: * Methods are forwarded directly to the decorated set.
26: *
27: * @since Commons Collections 3.0
28: * @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
29: *
30: * @author Stephen Colebourne
31: */
32: public abstract class AbstractSortedSetDecorator extends
33: 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: }
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