| /* Iterator.java -- Interface for iterating over collections |
| Copyright (C) 1998 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| As a special exception, if you link this library with other files to |
| produce an executable, this library does not by itself cause the |
| resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why the |
| executable file might be covered by the GNU General Public License. */ |
| |
| |
| 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. |
| */ |
| public interface Iterator |
| { |
| /** |
| * Tests whether there are elements remaining in the collection. |
| * |
| * @return true if there is at least one more element in the collection, |
| * that is, if the next call to next will not throw NoSuchElementException. |
| */ |
| boolean hasNext(); |
| |
| /** |
| * Obtain the next element in the collection. |
| * |
| * @return the next element in the collection |
| * @exception NoSuchElementException if there are no more elements |
| */ |
| Object next(); |
| |
| /** |
| * Remove from the underlying collection the last element returned by next. |
| * This method can be called only once after each call to next. It does not |
| * affect what will be returned by subsequent calls to next. This operation is |
| * optional, it may throw an UnsupportedOperationException. |
| * |
| * @exception IllegalStateException if next has not yet been called or remove |
| * has already been called since the last call to next. |
| * @exception UnsupportedOperationException if this Iterator does not support |
| * the remove operation. |
| */ |
| void remove(); |
| } |