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Java > Open Source Codes > net > sf > jga > util > EnumerationIterator


1 // ============================================================================
2 // $Id: EnumerationIterator.java,v 1.7 2005/08/02 23:45:22 davidahall Exp $
3 // Copyright (c) 2003-2005 David A. Hall
4 // ============================================================================
5 // The contents of this file are subject to the Common Development and
6 // Distribution License (CDDL), Version 1.0 (the License); you may not use this
7 // file except in compliance with the License. You should have received a copy
8 // of the the License along with this file: if not, a copy of the License is
9 // available from Sun Microsystems, Inc.
10 //
11 // http://www.sun.com/cddl/cddl.html
12 //
13 // From time to time, the license steward (initially Sun Microsystems, Inc.) may
14 // publish revised and/or new versions of the License. You may not use,
15 // distribute, or otherwise make this file available under subsequent versions
16 // of the License.
17 //
18 // Alternatively, the contents of this file may be used under the terms of the
19 // GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which
20 // case the provisions of the LGPL are applicable instead of those above. If you
21 // wish to allow use of your version of this file only under the terms of the
22 // LGPL, and not to allow others to use your version of this file under the
23 // terms of the CDDL, indicate your decision by deleting the provisions above
24 // and replace them with the notice and other provisions required by the LGPL.
25 // If you do not delete the provisions above, a recipient may use your version
26 // of this file under the terms of either the CDDL or the LGPL.
27 //
28 // This library is distributed in the hope that it will be useful,
29 // but WITHOUT ANY WARRANTY; without even the implied warranty of
30 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
31 // ============================================================================
32
33 package net.sf.jga.util;
34
35 import java.util.Enumeration JavaDoc;
36 import java.util.NoSuchElementException JavaDoc;
37 import java.util.Iterator JavaDoc;
38
39 /**
40  * Adapts an Enumeration to the Iterator and Iterable interfaces.
41  * <p>
42  * Copyright &copy; 2003-2005 David A. Hall
43  *
44  * @author <a HREF="mailto:davidahall@users.sourceforge.net">David A. Hall</a>
45  **/
46
47 public class EnumerationIterator<T> implements Iterator JavaDoc<T>, Iterable JavaDoc<T> {
48
49     // The base enumeration (as if that wasn't self-evident)
50 private Enumeration JavaDoc<T> _base;
51
52     /**
53      * Builds an EnumerationIterator that adapts the given enumeration to the
54      * Iterator and Iterable interfaces.
55      * @throws IllegalArgumentException if the given enumeration is null.
56      */
57     
58     public EnumerationIterator(Enumeration JavaDoc<T> enumeration)
59     {
60         if (enumeration == null)
61             throw new IllegalArgumentException JavaDoc();
62         
63         _base = enumeration;
64     }
65
66     // - - - - - - - - - - -
67 // Iterable<T> interface
68 // - - - - - - - - - - -
69
70     public Iterator JavaDoc<T> iterator() { return this; }
71     
72     // - - - - - - - - - - -
73 // Iterator<T> interface
74 // - - - - - - - - - - -
75
76     /**
77      * Returns true if the base enumeration has elements remaining.
78      * @return true if the base enumeration has elements remaining.
79      */
80
81     public boolean hasNext(){
82         return _base.hasMoreElements();
83     }
84
85     /**
86      * Returns the next element in the base enumeration.
87      * @return the next element in the base enumeration.
88      * @throws NoSuchElementException if the base enumeration is at its end.
89      */
90
91     public T next() {
92         return _base.nextElement();
93     }
94
95     /**
96      * throws UnsupportedOperationException: Enumerations do not support the
97      * removal of elements.
98      * @throws UnsupportedOperationException when called.
99      */
100
101     public void remove() throws UnsupportedOperationException JavaDoc {
102         throw new UnsupportedOperationException JavaDoc();
103     }
104 }
105
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