01: /*
02: * Copyright 1999-2004 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.iterators;
17:
18: import org.apache.commons.collections.MapIterator;
19: import org.apache.commons.collections.Unmodifiable;
20:
21: /**
22: * Decorates a map iterator such that it cannot be modified.
23: *
24: * @since Commons Collections 3.0
25: * @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
26: *
27: * @author Stephen Colebourne
28: */
29: public final class UnmodifiableMapIterator implements MapIterator,
30: Unmodifiable {
31:
32: /** The iterator being decorated */
33: private MapIterator iterator;
34:
35: //-----------------------------------------------------------------------
36: /**
37: * Decorates the specified iterator such that it cannot be modified.
38: *
39: * @param iterator the iterator to decorate
40: * @throws IllegalArgumentException if the iterator is null
41: */
42: public static MapIterator decorate(MapIterator iterator) {
43: if (iterator == null) {
44: throw new IllegalArgumentException(
45: "MapIterator must not be null");
46: }
47: if (iterator instanceof Unmodifiable) {
48: return iterator;
49: }
50: return new UnmodifiableMapIterator(iterator);
51: }
52:
53: //-----------------------------------------------------------------------
54: /**
55: * Constructor.
56: *
57: * @param iterator the iterator to decorate
58: */
59: private UnmodifiableMapIterator(MapIterator iterator) {
60: super ();
61: this .iterator = iterator;
62: }
63:
64: //-----------------------------------------------------------------------
65: public boolean hasNext() {
66: return iterator.hasNext();
67: }
68:
69: public Object next() {
70: return iterator.next();
71: }
72:
73: public Object getKey() {
74: return iterator.getKey();
75: }
76:
77: public Object getValue() {
78: return iterator.getValue();
79: }
80:
81: public Object setValue(Object value) {
82: throw new UnsupportedOperationException(
83: "setValue() is not supported");
84: }
85:
86: public void remove() {
87: throw new UnsupportedOperationException(
88: "remove() is not supported");
89: }
90:
91: }
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