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src/java.base/share/classes/java/util/Iterator.java

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rev 11962 : 8072726: add adapter to convert Enumeration to Iterator
Reviewed-by: redestad, forax, chegar, dfuchs, psandoz
   1 /*
   2  * Copyright (c) 1997, 2013, 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


  26 package java.util;
  27 
  28 import java.util.function.Consumer;
  29 
  30 /**
  31  * An iterator over a collection.  {@code Iterator} takes the place of
  32  * {@link Enumeration} in the Java Collections Framework.  Iterators
  33  * differ from enumerations in two ways:
  34  *
  35  * <ul>
  36  *      <li> Iterators allow the caller to remove elements from the
  37  *           underlying collection during the iteration with well-defined
  38  *           semantics.
  39  *      <li> Method names have been improved.
  40  * </ul>
  41  *
  42  * <p>This interface is a member of the
  43  * <a href="{@docRoot}/../technotes/guides/collections/index.html">
  44  * Java Collections Framework</a>.
  45  *




  46  * @param <E> the type of elements returned by this iterator
  47  *
  48  * @author  Josh Bloch
  49  * @see Collection
  50  * @see ListIterator
  51  * @see Iterable
  52  * @since 1.2
  53  */
  54 public interface Iterator<E> {
  55     /**
  56      * Returns {@code true} if the iteration has more elements.
  57      * (In other words, returns {@code true} if {@link #next} would
  58      * return an element rather than throwing an exception.)
  59      *
  60      * @return {@code true} if the iteration has more elements
  61      */
  62     boolean hasNext();
  63 
  64     /**
  65      * Returns the next element in the iteration.


   1 /*
   2  * Copyright (c) 1997, 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


  26 package java.util;
  27 
  28 import java.util.function.Consumer;
  29 
  30 /**
  31  * An iterator over a collection.  {@code Iterator} takes the place of
  32  * {@link Enumeration} in the Java Collections Framework.  Iterators
  33  * differ from enumerations in two ways:
  34  *
  35  * <ul>
  36  *      <li> Iterators allow the caller to remove elements from the
  37  *           underlying collection during the iteration with well-defined
  38  *           semantics.
  39  *      <li> Method names have been improved.
  40  * </ul>
  41  *
  42  * <p>This interface is a member of the
  43  * <a href="{@docRoot}/../technotes/guides/collections/index.html">
  44  * Java Collections Framework</a>.
  45  *
  46  * @apiNote
  47  * An {@link Enumeration} can be converted into an {@code Iterator} by
  48  * using the {@link Enumeration#asIterator} method.
  49  * 
  50  * @param <E> the type of elements returned by this iterator
  51  *
  52  * @author  Josh Bloch
  53  * @see Collection
  54  * @see ListIterator
  55  * @see Iterable
  56  * @since 1.2
  57  */
  58 public interface Iterator<E> {
  59     /**
  60      * Returns {@code true} if the iteration has more elements.
  61      * (In other words, returns {@code true} if {@link #next} would
  62      * return an element rather than throwing an exception.)
  63      *
  64      * @return {@code true} if the iteration has more elements
  65      */
  66     boolean hasNext();
  67 
  68     /**
  69      * Returns the next element in the iteration.


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