package scjlibs.util; /* * %W% %E% * * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ /** * An iterator over a collection. Iterator takes the place of Enumeration in * the Java collections framework. Iterators differ from enumerations in two * ways: <ul> * <li> Iterators allow the caller to remove elements from the * underlying collection during the iteration with well-defined * semantics. * <li> Method names have been improved. * </ul><p> * * This interface is a member of the * <a href="{@docRoot}/../technotes/guides/collections/index.html"> * Java Collections Framework</a>. * * @author Josh Bloch * @version %I%, %G% * @see Collection * @see ListIterator * @see Enumeration * @since 1.2 */ public interface Iterator<E> { /** * Returns <tt>true</tt> if the iteration has more elements. (In other * words, returns <tt>true</tt> if <tt>next</tt> would return an element * rather than throwing an exception.) * * @return <tt>true</tt> if the iterator has more elements. */ boolean hasNext(); /** * Returns the next element in the iteration. * * @return the next element in the iteration. * @exception NoSuchElementException iteration has no more elements. */ E next(); /** * * Removes from the underlying collection the last element returned by the * iterator (optional operation). This method can be called only once per * call to <tt>next</tt>. The behavior of an iterator is unspecified if * the underlying collection is modified while the iteration is in * progress in any way other than by calling this method. * * @exception UnsupportedOperationException if the <tt>remove</tt> * operation is not supported by this Iterator. * @exception IllegalStateException if the <tt>next</tt> method has not * yet been called, or the <tt>remove</tt> method has already * been called after the last call to the <tt>next</tt> * method. */ void remove(); }