IdentityHashMap


1   /**
2    * Copyright (C) The Apache Software Foundation. All rights reserved.
3    *
4    * This software is published under the terms of the Apache Software License
5    * version 1.1, a copy of which has been included with this distribution in
6    * the docs/licenses/apache-1.1.txt file.
7    */
8   package org.jboss.axis.utils;
9   
10  import java.util.HashMap  ;
11  import java.util.Map  ;
12  
13  /**
14   * IdentityHashMap similar to JDK1.4's java.util.IdentityHashMap
15   *
16   * @author Davanum Srinivas <dims@yahoo.com>
17   */
18  public class IdentityHashMap extends HashMap  
19  {
20     /**
21      * Constructor for IdentityHashMap.
22      *
23      * @param initialCapacity
24      * @param loadFactor
25      */
26     public IdentityHashMap(int initialCapacity, float loadFactor)
27     {
28        super(initialCapacity, loadFactor);
29     }
30  
31     /**
32      * Constructor for IdentityHashMap.
33      *
34      * @param initialCapacity
35      */
36     public IdentityHashMap(int initialCapacity)
37     {
38        super(initialCapacity);
39     }
40  
41     /**
42      * Constructor for IdentityHashMap.
43      */
44     public IdentityHashMap()
45     {
46        super();
47     }
48  
49     /**
50      * Constructor for IdentityHashMap.
51      *
52      * @param t
53      */
54     public IdentityHashMap(Map   t)
55     {
56        super(t);
57     }
58  
59     /**
60      * @see Map#get(Object)
61      */
62     public Object   get(Object   key)
63     {
64        return super.get(new IDKey(key));
65     }
66  
67     /**
68      * @see Map#put(Object, Object)
69      */
70     public Object   put(Object   key, Object   value)
71     {
72        return super.put(new IDKey(key), value);
73     }
74  
75     /**
76      * adds an object to the Map. new Identity(obj) is used as key
77      */
78     public Object   add(Object   value)
79     {
80        Object   key = new IDKey(value);
81        if (!super.containsKey(key))
82        {
83           return super.put(key, value);
84        }
85        else
86           return null;
87  
88     }
89  
90     /**
91      * @see Map#remove(Object)
92      */
93     public Object   remove(Object   key)
94     {
95        return super.remove(new IDKey(key));
96     }
97  
98     /**
99      * @see Map#containsKey(Object)
100     */
101    public boolean containsKey(Object   key)
102    {
103       return super.containsKey(new IDKey(key));
104    }
105 }
106
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