Mega Code Archive
Protects an given iterator by preventing calls to remove()
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/*
* JCommon : a free general purpose class library for the Java(tm) platform
*
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ---------------------
* ReadOnlyIterator.java
* ---------------------
* (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
*
* Original Author: Thomas Morgner;
* Contributor(s): -;
*
* $Id: ReadOnlyIterator.java,v 1.2 2005/10/18 13:24:19 mungady Exp $
*
* Changes
* -------------------------
* 18-Jul-2003 : Initial version
*
*/
import java.util.Iterator;
/**
* Protects an given iterator by preventing calls to remove().
*
* @author Thomas Morgner
*/
public class ReadOnlyIterator implements Iterator {
/** The base iterator which we protect. */
private Iterator base;
/**
* Creates a new read-only iterator for the given iterator.
*
* @param it the iterator.
*/
public ReadOnlyIterator(final Iterator it) {
if (it == null) {
throw new NullPointerException("Base iterator is null.");
}
this.base = it;
}
/**
* 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.
*/
public boolean hasNext() {
return this.base.hasNext();
}
/**
* Returns the next element in the iteration.
* Throws NoSuchElementException when iteration has no more elements.
*
* @return the next element in the iteration.
*/
public Object next() {
return this.base.next();
}
/**
* Throws <code>UnsupportedOperationException</code>.
*/
public void remove() {
throw new UnsupportedOperationException();
}
}
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