1 /*
   2  * Copyright (c) 1994, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any

  59  * @see     java.util.Vector#elements()
  60  *
  61  * @author  Lee Boynton
  62  * @since   1.0
  63  */
  64 public interface Enumeration<E> {
  65     /**
  66      * Tests if this enumeration contains more elements.
  67      *
  68      * @return  {@code true} if and only if this enumeration object
  69      *           contains at least one more element to provide;
  70      *          {@code false} otherwise.
  71      */
  72     boolean hasMoreElements();
  73 
  74     /**
  75      * Returns the next element of this enumeration if this enumeration
  76      * object has at least one more element to provide.
  77      *
  78      * @return     the next element of this enumeration.
  79      * @exception  NoSuchElementException  if no more elements exist.
  80      */
  81     E nextElement();
  82 
  83     /**
  84      * Returns an {@link Iterator} that traverses the remaining elements
  85      * covered by this enumeration. Traversal is undefined if any methods
  86      * are called on this enumeration after the call to {@code asIterator}.
  87      *
  88      * @apiNote
  89      * This method is intended to help adapt code that produces
  90      * {@code Enumeration} instances to code that consumes {@code Iterator}
  91      * instances. For example, the {@link java.util.jar.JarFile#entries
  92      * JarFile.entries()} method returns an {@code Enumeration<JarEntry>}.
  93      * This can be turned into an {@code Iterator}, and then the
  94      * {@code forEachRemaining()} method can be used:
  95      *
  96      * <pre>{@code
  97      *     JarFile jarFile = ... ;
  98      *     jarFile.entries().asIterator().forEachRemaining(entry -> { ... });
  99      * }</pre>

   1 /*
   2  * Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any

  59  * @see     java.util.Vector#elements()
  60  *
  61  * @author  Lee Boynton
  62  * @since   1.0
  63  */
  64 public interface Enumeration<E> {
  65     /**
  66      * Tests if this enumeration contains more elements.
  67      *
  68      * @return  {@code true} if and only if this enumeration object
  69      *           contains at least one more element to provide;
  70      *          {@code false} otherwise.
  71      */
  72     boolean hasMoreElements();
  73 
  74     /**
  75      * Returns the next element of this enumeration if this enumeration
  76      * object has at least one more element to provide.
  77      *
  78      * @return     the next element of this enumeration.
  79      * @throws     NoSuchElementException  if no more elements exist.
  80      */
  81     E nextElement();
  82 
  83     /**
  84      * Returns an {@link Iterator} that traverses the remaining elements
  85      * covered by this enumeration. Traversal is undefined if any methods
  86      * are called on this enumeration after the call to {@code asIterator}.
  87      *
  88      * @apiNote
  89      * This method is intended to help adapt code that produces
  90      * {@code Enumeration} instances to code that consumes {@code Iterator}
  91      * instances. For example, the {@link java.util.jar.JarFile#entries
  92      * JarFile.entries()} method returns an {@code Enumeration<JarEntry>}.
  93      * This can be turned into an {@code Iterator}, and then the
  94      * {@code forEachRemaining()} method can be used:
  95      *
  96      * <pre>{@code
  97      *     JarFile jarFile = ... ;
  98      *     jarFile.entries().asIterator().forEachRemaining(entry -> { ... });
  99      * }</pre>