001/* NamingEnumeration.java -- The JNDI enumeration
002   Copyright (C) 2000, 2006 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038 
039package javax.naming;
040
041import java.util.Enumeration;
042
043/**
044 * <p>The specific type of enumeration that supports throwing various exceptions by
045 * the hasMore method. The exceptions are only thrown if the enumeration is
046 * scanned using {@link #next()} and {@link #hasMore()}. If the inherited
047 * {@link java.util.Enumeration#nextElement()} and
048 * {@link Enumeration#hasMoreElements()} are used instead, the exceptions are
049 * not throwed, and the enumeration is just iterated over available elements.
050 * </p>
051 * <p>This enumeration becomes invalid after throwing the exception. If the
052 * exception has been thrown, not other method should be called of that
053 * enumeration.</p>
054 */
055public interface NamingEnumeration<T> extends Enumeration<T>
056{
057  /**
058   * Returns the next element in this enumeration. The naming - specific
059   * exceptions are only throws after returning all still available elements of
060   * the enumeration.
061   * 
062   * @return the next element of this enumeration
063   * @throws NamingException
064   */
065  T next() throws NamingException;
066  
067  /**
068   * Checks if there are more unvisited elements in the enumeration, throwing
069   * exceptions if there are some unvisited, but not available elements.
070   * 
071   * @return true if there are some unvisited elements, false otherwise.
072   * @throws PartialResultException if the enumeration, returned by the
073   *           {@link Context#list(Name)} or other similar method contains only
074   *           partial answer.
075   * @throws SizeLimitExceededException if remaining elements are not available
076   *           because of the previously specified size limit.
077   * @throws NamingException
078   */
079  boolean hasMore() throws NamingException;
080  
081  /**
082   * Immediately frees all resources, owned by this enumeration. If invoked, it
083   * must be the last method called for that enumeration.
084   * 
085   * @throws NamingException
086   */  
087  void close() throws NamingException;
088
089}