/*
* 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 com.hp.hpl.jena.sparql.graph;
import org.slf4j.Logger ;
import org.slf4j.LoggerFactory ;
import com.hp.hpl.jena.graph.Graph ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.graph.Triple ;
import com.hp.hpl.jena.graph.TripleMatch ;
import com.hp.hpl.jena.graph.impl.GraphBase ;
import com.hp.hpl.jena.sparql.algebra.Op ;
import com.hp.hpl.jena.sparql.algebra.op.OpBGP ;
import com.hp.hpl.jena.sparql.core.BasicPattern ;
import com.hp.hpl.jena.sparql.core.Var ;
import com.hp.hpl.jena.util.iterator.ExtendedIterator ;
/** This class provides the Jena Graph interface to a remote SPARQL endpoint.
* Efficiency not guaranteed. */
public class GraphSPARQLService extends GraphBase implements Graph
{
private static Logger log = LoggerFactory.getLogger(GraphSPARQLService.class) ;
private String serviceURI ;
private String graphIRI = null ;
// Remote default graph
public GraphSPARQLService(String serviceURI)
{
this.serviceURI = serviceURI ;
this.graphIRI = null ;
}
// Remote named graph
public GraphSPARQLService(String serviceURI, String graphIRI)
{
this.serviceURI = serviceURI ;
this.graphIRI = graphIRI ;
}
// @Override
// public Capabilities getCapabilities()
// {
// if (capabilities == null)
// capabilities = new AllCapabilities()
// { @Override public boolean handlesLiteralTyping() { return false; } };
// return capabilities;
// }
// @SuppressWarnings("null")
// @Override
@Override
protected ExtendedIterator<Triple> graphBaseFind(TripleMatch m)
{
Node s = m.getMatchSubject() ;
Var sVar = null ;
if ( s == null )
{
sVar = Var.alloc("s") ;
s = sVar ;
}
Node p = m.getMatchPredicate() ;
Var pVar = null ;
if ( p == null )
{
pVar = Var.alloc("p") ;
p = pVar ;
}
Node o = m.getMatchObject() ;
Var oVar = null ;
if ( o == null )
{
oVar = Var.alloc("o") ;
o = oVar ;
}
Triple triple = new Triple(s, p ,o) ;
// Evaluate as an algebra expression
BasicPattern pattern = new BasicPattern() ;
pattern.add(triple) ;
Op op = new OpBGP(pattern) ;
// // Make remote execution object.
// System.err.println("GraphSPARQLService.graphBaseFind: Unimplemented : remote service execution") ;
// //Plan plan = factory.create(op, getDataset(), BindingRoot.create(), null) ;
//
// QueryIterator qIter = plan.iterator() ;
// List<Triple> triples = new ArrayList<Triple>() ;
//
//
// for (; qIter.hasNext() ; )
// {
// Binding b = qIter.nextBinding() ;
// Node sResult = s ;
// Node pResult = p ;
// Node oResult = o ;
// if ( sVar != null )
// sResult = b.get(sVar) ;
// if ( pVar != null )
// pResult = b.get(pVar) ;
// if ( oVar != null )
// oResult = b.get(oVar) ;
// Triple resultTriple = new Triple(sResult, pResult, oResult) ;
// if ( log.isDebugEnabled() )
// log.debug(" "+resultTriple) ;
// triples.add(resultTriple) ;
// }
// qIter.close() ;
// return WrappedIterator.createNoRemove(triples.iterator()) ;
return null ;
}
}