| /* Iterator.java -- Interface for iterating over collections |
| Copyright (C) 1998, 2001, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
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| exception statement from your version. */ |
| |
| |
| package java.util; |
| |
| /** |
| * An object which iterates over a collection. An Iterator is used to return |
| * the items once only, in sequence, by successive calls to the next method. |
| * It is also possible to remove elements from the underlying collection by |
| * using the optional remove method. Iterator is intended as a replacement |
| * for the Enumeration interface of previous versions of Java, which did not |
| * have the remove method and had less conveniently named methods. |
| * |
| * @author Original author unknown |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @see Collection |
| * @see ListIterator |
| * @see Enumeration |
| * @since 1.2 |
| * @status updated to 1.4 |
| */ |
| public interface Iterator |
| { |
| /** |
| * Tests whether there are elements remaining in the collection. In other |
| * words, calling <code>next()</code> will not throw an exception. |
| * |
| * @return true if there is at least one more element in the collection |
| */ |
| boolean hasNext(); |
| |
| /** |
| * Obtain the next element in the collection. |
| * |
| * @return the next element in the collection |
| * @throws NoSuchElementException if there are no more elements |
| */ |
| Object next(); |
| |
| /** |
| * Remove from the underlying collection the last element returned by next |
| * (optional operation). This method can be called only once after each |
| * call to <code>next()</code>. It does not affect what will be returned |
| * by subsequent calls to next. |
| * |
| * @throws IllegalStateException if next has not yet been called or remove |
| * has already been called since the last call to next. |
| * @throws UnsupportedOperationException if this Iterator does not support |
| * the remove operation. |
| */ |
| void remove(); |
| } |