/* * Copyright (c) 1994, 2005, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ 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(); }