/**
* Copyright (C) 2010 eXo Platform SAS.
*
* This 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 software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xcmis.spi;
import java.util.NoSuchElementException;
/**
* @author <a href="mailto:andrew00x@gmail.com">Andrey Parfonov</a>
* @version $Id$
*/
public abstract class LazyIterator<T> implements ItemsIterator<T>
{
protected T next;
/**
* {@inheritDoc}
*/
public boolean hasNext()
{
return next != null;
}
/**
* {@inheritDoc}
*/
public T next()
{
if (next == null)
{
throw new NoSuchElementException();
}
T n = next;
fetchNext();
return n;
}
/**
* {@inheritDoc}
*/
public void remove()
{
throw new UnsupportedOperationException("remove");
}
/**
* {@inheritDoc}
*/
public void skip(int skip) throws NoSuchElementException
{
while (skip-- > 0)
{
fetchNext();
if (next == null)
{
throw new NoSuchElementException();
}
}
}
/**
* To fetch next item and set it in field <code>next</code>
*/
protected abstract void fetchNext();
}