/* * Copyright (c) 1994, 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.util; /** * An object that implements the Enumeration interface generates a * series of elements, one at a time. Successive calls to the * <code>nextElement</code> method return successive elements of the * series. * <p> * For example, to print all elements of a <tt>Vector&lt;E&gt;</tt> <i>v</i>: * <pre> *   for (Enumeration&lt;E&gt; e = v.elements(); e.hasMoreElements();) *       System.out.println(e.nextElement());</pre> * <p> * Methods are provided to enumerate through the elements of a * vector, the keys of a hashtable, and the values in a hashtable. * Enumerations are also used to specify the input streams to a * <code>SequenceInputStream</code>. * <p> * NOTE: The functionality of this interface is duplicated by the Iterator * interface.  In addition, Iterator adds an optional remove operation, and * has shorter method names.  New implementations should consider using * Iterator in preference to Enumeration. * * @see     java.util.Iterator * @see     java.io.SequenceInputStream * @see     java.util.Enumeration#nextElement() * @see     java.util.Hashtable * @see     java.util.Hashtable#elements() * @see     java.util.Hashtable#keys() * @see     java.util.Vector * @see     java.util.Vector#elements() * * @author  Lee Boynton * @since   JDK1.0 */public interface Enumeration<E> {    /**     * Tests if this enumeration contains more elements.     *     * @return  <code>true</code> if and only if this enumeration object     *           contains at least one more element to provide;     *          <code>false</code> otherwise.     */    boolean hasMoreElements();     /**     * Returns the next element of this enumeration if this enumeration     * object has at least one more element to provide.     *     * @return     the next element of this enumeration.     * @exception  NoSuchElementException  if no more elements exist.     */    E nextElement();}