Simple Pizza Query

[Andrés Zules]

Hi everyone

I use Protege Version 3.4.7 (Build 620) and execute a simple query in the
SPARQL Query Panel on http://www.co-ode.org/ontologies/pizza/pizza.owl:

SELECT ?NombrePizza
> WHERE {
>  ?NombrePizza ?Relacion pizza:MushroomTopping .
>  ?Relacion owl:inverseOf pizza:isToppingOf .
> }


The result is 4 pizzas:

 DefaultOWLNamedClass(
> http://www.co-ode.org/ontologies/pizza/pizza.owl#FourSeasons)

  DefaultOWLNamedClass(
> http://www.co-ode.org/ontologies/pizza/pizza.owl#Mushroom)

  DefaultOWLNamedClass(
> http://www.co-ode.org/ontologies/pizza/pizza.owl#Giardiniera)

  DefaultOWLNamedClass(
> http://www.co-ode.org/ontologies/pizza/pizza.owl#LaReine)


Then I execute the same query with jena

package Jena;
> import com.hp.hpl.jena.graph.query.Query;
> import com.hp.hpl.jena.query.*;
> import com.hp.hpl.jena.rdf.model.*;
> import com.hp.hpl.jena.reasoner.Reasoner;
> import com.hp.hpl.jena.reasoner.ReasonerRegistry;
> import com.hp.hpl.jena.reasoner.ValidityReport;
> import java.util.Iterator;
> public class Test {
>
>     public static void main(String args[]) {
>         Model model = ModelFactory.createDefaultModel();
>         model.read("http://localhost:8080/volcano/w3/pizza-latest.owl";,
> "RDF/XML");
>
>         model.write(System.out);
>
>         Reasoner reasoner = ReasonerRegistry.getOWLMicroReasoner();
>         InfModel inf = ModelFactory.createInfModel(reasoner, model);
>
>         ValidityReport validity = inf.validate();
>         if (validity.isValid()) {
>             System.out.println("OK: El Modelo Inferido es correcto.");
>         } else {
>             System.out.println("Conflictos");
>             for (Iterator i = validity.getReports(); i.hasNext();) {
>                 System.out.println(" - " + i.next());
>             }
>         }
>
>         inf.write(System.out);
>
>         String prefix = "PREFIX pizza:<
> http://www.co-ode.org/ontologies/pizza/pizza.owl#>"
>                 + " PREFIX owl:<http://www.w3.org/2002/07/owl#>"
>                 + " PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#>";
>
>         String queryString1 = prefix + " SELECT ?NombrePizza WHERE {"
>                 + " ?NombrePizza ?Relacion pizza:MushroomTopping ."
>                 + " ?Relacion owl:inverseOf pizza:isToppingOf }";
>
>         com.hp.hpl.jena.query.Query query =
> QueryFactory.create(queryString1) ;
>         QueryExecution qexec = QueryExecutionFactory.create(query, inf);
>
>         try {
>             ResultSet results = qexec.execSelect() ;
>             ResultSetFormatter.out(results, query);
>         } finally {
>             qexec.close();
>         }
>     }
> }


And the result is empty:

-----------------------
> | NombrePizza |
> ============
> -----------------------


I don't know what is my mistake. Do you have any idea?. Thank you very much.

- - -
FAZA