2 * Copyright (c) 1994, 2005, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
29 * An object that implements the Enumeration interface generates a
30 * series of elements, one at a time. Successive calls to the
31 * <code>nextElement</code> method return successive elements of the
34 * For example, to print all elements of a <tt>Vector<E></tt> <i>v</i>:
36 * for (Enumeration<E> e = v.elements(); e.hasMoreElements();)
37 * System.out.println(e.nextElement());</pre>
39 * Methods are provided to enumerate through the elements of a
40 * vector, the keys of a hashtable, and the values in a hashtable.
41 * Enumerations are also used to specify the input streams to a
42 * <code>SequenceInputStream</code>.
44 * NOTE: The functionality of this interface is duplicated by the Iterator
45 * interface. In addition, Iterator adds an optional remove operation, and
46 * has shorter method names. New implementations should consider using
47 * Iterator in preference to Enumeration.
49 * @see java.util.Iterator
50 * @see java.io.SequenceInputStream
51 * @see java.util.Enumeration#nextElement()
52 * @see java.util.Hashtable
53 * @see java.util.Hashtable#elements()
54 * @see java.util.Hashtable#keys()
55 * @see java.util.Vector
56 * @see java.util.Vector#elements()
61 public interface Enumeration<E> {
63 * Tests if this enumeration contains more elements.
65 * @return <code>true</code> if and only if this enumeration object
66 * contains at least one more element to provide;
67 * <code>false</code> otherwise.
69 boolean hasMoreElements();
72 * Returns the next element of this enumeration if this enumeration
73 * object has at least one more element to provide.
75 * @return the next element of this enumeration.
76 * @exception NoSuchElementException if no more elements exist.