API Overview API Index Package Overview Direct link to this page
JDK 1.6
  java.util. Dictionary View Javadoc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

/*
 * @(#)Dictionary.java	1.24 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.util;

/**
 * The <code>Dictionary</code> class is the abstract parent of any 
 * class, such as <code>Hashtable</code>, which maps keys to values. 
 * Every key and every value is an object. In any one <tt>Dictionary</tt> 
 * object, every key is associated with at most one value. Given a 
 * <tt>Dictionary</tt> and a key, the associated element can be looked up. 
 * Any non-<code>null</code> object can be used as a key and as a value.
 * <p>
 * As a rule, the <code>equals</code> method should be used by 
 * implementations of this class to decide if two keys are the same. 
 * <p>
 * <strong>NOTE: This class is obsolete.  New implementations should
 * implement the Map interface, rather than extending this class.</strong>
 *
 * @author  unascribed
 * @version 1.24, 11/17/05
 * @see	    java.util.Map
 * @see     java.lang.Object#equals(java.lang.Object)
 * @see     java.lang.Object#hashCode()
 * @see     java.util.Hashtable
 * @since   JDK1.0
 */
public abstract
class Dictionary<K,V> {
    /**
     * Sole constructor.  (For invocation by subclass constructors, typically
     * implicit.)
     */
    public Dictionary() {
    }

    /**
     * Returns the number of entries (distinct keys) in this dictionary.
     *
     * @return  the number of keys in this dictionary.
     */
    abstract public int size();

    /**
     * Tests if this dictionary maps no keys to value. The general contract 
     * for the <tt>isEmpty</tt> method is that the result is true if and only 
     * if this dictionary contains no entries. 
     *
     * @return  <code>true</code> if this dictionary maps no keys to values;
     *          <code>false</code> otherwise.
     */
    abstract public boolean isEmpty();

    /**
     * Returns an enumeration of the keys in this dictionary. The general 
     * contract for the keys method is that an <tt>Enumeration</tt> object 
     * is returned that will generate all the keys for which this dictionary 
     * contains entries. 
     *
     * @return  an enumeration of the keys in this dictionary.
     * @see     java.util.Dictionary#elements()
     * @see     java.util.Enumeration
     */
    abstract public Enumeration<K> keys();

    /**
     * Returns an enumeration of the values in this dictionary. The general 
     * contract for the <tt>elements</tt> method is that an 
     * <tt>Enumeration</tt> is returned that will generate all the elements 
     * contained in entries in this dictionary.
     *
     * @return  an enumeration of the values in this dictionary.
     * @see     java.util.Dictionary#keys()
     * @see     java.util.Enumeration
     */
    abstract public Enumeration<V> elements();

    /**
     * Returns the value to which the key is mapped in this dictionary. 
     * The general contract for the <tt>isEmpty</tt> method is that if this 
     * dictionary contains an entry for the specified key, the associated 
     * value is returned; otherwise, <tt>null</tt> is returned. 
     *
     * @return  the value to which the key is mapped in this dictionary;
     * @param   key   a key in this dictionary.
     *          <code>null</code> if the key is not mapped to any value in
     *          this dictionary.
     * @exception NullPointerException if the <tt>key</tt> is <tt>null</tt>.
     * @see     java.util.Dictionary#put(java.lang.Object, java.lang.Object)
     */
    abstract public V get(Object key);

    /**
     * Maps the specified <code>key</code> to the specified 
     * <code>value</code> in this dictionary. Neither the key nor the 
     * value can be <code>null</code>.
     * <p>
     * If this dictionary already contains an entry for the specified 
     * <tt>key</tt>, the value already in this dictionary for that 
     * <tt>key</tt> is returned, after modifying the entry to contain the
     *  new element. <p>If this dictionary does not already have an entry 
     *  for the specified <tt>key</tt>, an entry is created for the 
     *  specified <tt>key</tt> and <tt>value</tt>, and <tt>null</tt> is 
     *  returned.
     * <p>
     * The <code>value</code> can be retrieved by calling the 
     * <code>get</code> method with a <code>key</code> that is equal to 
     * the original <code>key</code>. 
     *
     * @param      key     the hashtable key.
     * @param      value   the value.
     * @return     the previous value to which the <code>key</code> was mapped
     *             in this dictionary, or <code>null</code> if the key did not
     *             have a previous mapping.
     * @exception  NullPointerException  if the <code>key</code> or
     *               <code>value</code> is <code>null</code>.
     * @see        java.lang.Object#equals(java.lang.Object)
     * @see        java.util.Dictionary#get(java.lang.Object)
     */
    abstract public V put(K key, V value);

    /**
     * Removes the <code>key</code> (and its corresponding 
     * <code>value</code>) from this dictionary. This method does nothing 
     * if the <code>key</code> is not in this dictionary. 
     *
     * @param   key   the key that needs to be removed.
     * @return  the value to which the <code>key</code> had been mapped in this
     *          dictionary, or <code>null</code> if the key did not have a
     *          mapping.
     * @exception NullPointerException if <tt>key</tt> is <tt>null</tt>.
     */
    abstract public V remove(Object key);
}

Generated By: JavaOnTracks Doclet 0.1.4     ©Thibaut Colar