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Java > Open Source Codes > org > apache > mina > util > IdentityHashSet


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License. You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied. See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  *
19  */
20 package org.apache.mina.util;
21
22 import java.util.AbstractSet JavaDoc;
23 import java.util.Collection JavaDoc;
24 import java.util.IdentityHashMap JavaDoc;
25 import java.util.Iterator JavaDoc;
26 import java.util.Map JavaDoc;
27 import java.util.Set JavaDoc;
28
29 /**
30  * An {@link IdentityHashMap}-backed {@link Set}.
31  *
32  * @author The Apache Directory Project (mina-dev@directory.apache.org)
33  * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (금, 13 7월 2007) $
34  */
35 public class IdentityHashSet<E> extends AbstractSet JavaDoc<E> {
36     private final Map JavaDoc<E, Boolean JavaDoc> delegate = new IdentityHashMap JavaDoc<E, Boolean JavaDoc>();
37
38     public IdentityHashSet() {
39     }
40
41     public IdentityHashSet(Collection JavaDoc<E> c) {
42         addAll(c);
43     }
44
45     @Override JavaDoc
46     public int size() {
47         return delegate.size();
48     }
49
50     @Override JavaDoc
51     public boolean contains(Object JavaDoc o) {
52         //noinspection SuspiciousMethodCalls
53 return delegate.containsKey(o);
54     }
55
56     @Override JavaDoc
57     public Iterator JavaDoc<E> iterator() {
58         return delegate.keySet().iterator();
59     }
60
61     @Override JavaDoc
62     public boolean add(E arg0) {
63         return delegate.put(arg0, Boolean.TRUE) == null;
64     }
65
66     @Override JavaDoc
67     public boolean remove(Object JavaDoc o) {
68         //noinspection SuspiciousMethodCalls
69 return delegate.remove(o) != null;
70     }
71
72     @Override JavaDoc
73     public void clear() {
74         delegate.clear();
75     }
76 }
77
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