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* 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
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*/
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<E></tt> <i>v</i>:
* <pre>
* for (Enumeration<E> 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();
}