/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.security.utils;
import com.hp.hpl.jena.rdf.model.RDFList;
import com.hp.hpl.jena.vocabulary.RDF;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class RDFListIterator implements Iterator<RDFList>
{
private RDFList current;
private Boolean found;
public RDFListIterator( final RDFList start )
{
this.current = start;
}
private boolean endOfList()
{
return current.equals(RDF.nil);
}
@Override
public boolean hasNext()
{
if ((found == null) && !endOfList())
{
found = !endOfList();
}
return found == null ? false : found;
}
private void incrementCurrent()
{
if (!endOfList())
{
current = current.getRequiredProperty(RDF.rest).getResource()
.as(RDFList.class);
}
}
@Override
public RDFList next()
{
if (hasNext())
{
found = null;
final RDFList retval = current;
incrementCurrent();
return retval;
}
throw new NoSuchElementException();
}
@Override
public void remove()
{
throw new UnsupportedOperationException();
}
}