/**
* Copyright (c) 2002-2013 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.helpers.collection;
import java.util.Iterator;
public abstract class CatchingIteratorWrapper<T, U> extends PrefetchingIterator<T>
{
private final Iterator<U> source;
public CatchingIteratorWrapper( Iterator<U> source )
{
this.source = source;
}
@Override
protected T fetchNextOrNull()
{
while ( source.hasNext() )
{
U nextItem = null;
try
{
nextItem = fetchNextOrNullFromSource( source );
if ( nextItem != null )
{
return underlyingObjectToObject( nextItem );
}
}
catch ( Throwable t )
{
if ( exceptionOk( t ) )
{
itemDodged( nextItem );
continue;
}
if ( t instanceof RuntimeException )
{
throw (RuntimeException) t;
}
else if ( t instanceof Error )
{
throw (Error) t;
}
throw new RuntimeException( t );
}
}
return null;
}
protected U fetchNextOrNullFromSource( Iterator<U> source )
{
return source.next();
}
protected void itemDodged( U item )
{
}
protected boolean exceptionOk( Throwable t )
{
return true;
}
protected abstract T underlyingObjectToObject( U object );
}