001/* Enumeration.java -- Interface for enumerating lists of objects 002 Copyright (C) 1998, 1999, 2001, 2004, 2005 003 Free Software Foundation, Inc. 004 005This file is part of GNU Classpath. 006 007GNU Classpath is free software; you can redistribute it and/or modify 008it under the terms of the GNU General Public License as published by 009the Free Software Foundation; either version 2, or (at your option) 010any later version. 011 012GNU Classpath is distributed in the hope that it will be useful, but 013WITHOUT ANY WARRANTY; without even the implied warranty of 014MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015General Public License for more details. 016 017You should have received a copy of the GNU General Public License 018along with GNU Classpath; see the file COPYING. If not, write to the 019Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02002110-1301 USA. 021 022Linking this library statically or dynamically with other modules is 023making a combined work based on this library. Thus, the terms and 024conditions of the GNU General Public License cover the whole 025combination. 026 027As a special exception, the copyright holders of this library give you 028permission to link this library with independent modules to produce an 029executable, regardless of the license terms of these independent 030modules, and to copy and distribute the resulting executable under 031terms of your choice, provided that you also meet, for each linked 032independent module, the terms and conditions of the license of that 033module. An independent module is a module which is not derived from 034or based on this library. If you modify this library, you may extend 035this exception to your version of the library, but you are not 036obligated to do so. If you do not wish to do so, delete this 037exception statement from your version. */ 038 039package java.util; 040 041/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 042 * "The Java Language Specification", ISBN 0-201-63451-1. 043 * Status: Believed complete and correct 044 */ 045 046/** 047 * Interface for lists of objects that can be returned in sequence. Successive 048 * objects are obtained by the nextElement method. 049 * <p> 050 * As of Java 1.2, the Iterator interface provides the same functionality, but 051 * with shorter method names and a new optional method to remove items from the 052 * list. If writing for 1.2, consider using Iterator instead. Enumerations over 053 * the new collections classes, for use with legacy APIs that require them, can 054 * be obtained by the enumeration method in class Collections. 055 * 056 * @author Warren Levy (warrenl@cygnus.com) 057 * @author Eric Blake (ebb9@email.byu.edu) 058 * @see Iterator 059 * @see Hashtable 060 * @see Vector 061 * @since 1.0 062 * @status updated to 1.4 063 */ 064public interface Enumeration<E> 065{ 066 /** 067 * Tests whether there are elements remaining in the enumeration. 068 * 069 * @return true if there is at least one more element in the enumeration, 070 * that is, if the next call to nextElement will not throw a 071 * NoSuchElementException. 072 */ 073 boolean hasMoreElements(); 074 075 /** 076 * Obtain the next element in the enumeration. 077 * 078 * @return the next element in the enumeration 079 * @throws NoSuchElementException if there are no more elements 080 */ 081 E nextElement(); 082}