01: /**
02: * Copyright (c) 2000-2008 Liferay, Inc. All rights reserved.
03: *
04: * Permission is hereby granted, free of charge, to any person obtaining a copy
05: * of this software and associated documentation files (the "Software"), to deal
06: * in the Software without restriction, including without limitation the rights
07: * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
08: * copies of the Software, and to permit persons to whom the Software is
09: * furnished to do so, subject to the following conditions:
10: *
11: * The above copyright notice and this permission notice shall be included in
12: * all copies or substantial portions of the Software.
13: *
14: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15: * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17: * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18: * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19: * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20: * SOFTWARE.
21: */package com.liferay.util;
22:
23: import com.liferay.portal.kernel.util.StringPool;
24:
25: import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
26:
27: import java.util.AbstractSet;
28: import java.util.Iterator;
29: import java.util.Map;
30: import java.util.Set;
31:
32: /**
33: * <a href="ConcurrentHashSet.java.html"><b><i>View Source</i></b></a>
34: *
35: * @author Brian Wing Shun Chan
36: *
37: */
38: public class ConcurrentHashSet extends AbstractSet {
39:
40: public ConcurrentHashSet() {
41: _map = new ConcurrentHashMap();
42: }
43:
44: public ConcurrentHashSet(int capacity) {
45: _map = new ConcurrentHashMap(capacity);
46: }
47:
48: public ConcurrentHashSet(Set set) {
49: Iterator itr = set.iterator();
50:
51: while (itr.hasNext()) {
52: Object obj = (Object) itr.next();
53:
54: _map.put(obj, StringPool.BLANK);
55: }
56: }
57:
58: public boolean add(Object obj) {
59: if (_map.put(obj, StringPool.BLANK) == null) {
60: return true;
61: } else {
62: return false;
63: }
64: }
65:
66: public void clear() {
67: _map.clear();
68: }
69:
70: public boolean contains(Object obj) {
71: if (_map.containsKey(obj)) {
72: return true;
73: } else {
74: return false;
75: }
76: }
77:
78: public Iterator iterator() {
79: return _map.keySet().iterator();
80: }
81:
82: public boolean remove(Object obj) {
83: if (_map.remove(obj) == null) {
84: return false;
85: } else {
86: return true;
87: }
88: }
89:
90: public int size() {
91: return _map.size();
92: }
93:
94: private Map _map;
95:
96: }
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