Hi there,
I'll start this mail with the typical "i'm very new to this semantic web
stuff".
I've been using Jena to develop my thesis to obtain the Computer Engineer
Degree, here in Venezuela. I've been following the tutorials ans, by now,
I'm able to load owl files into Jena InfModels and run Pellet over that
model to make inferences. I can also write RDF or add triplets to an
existent RDF model. But i'm having some trouble by doing the same thing when
I load the triplets from a Database Engine like Virtuoso (I decided to use
it because it supports RDF, RDFS and some OWL-DL by default, or that's what
I've read)
Here's the thing, since i was doing some testing with Jena loading my owl
file on an InfModel and doing the inferences with that, I thought it would
be pretty much the same if I load the model from a database, but for some
reason it just fails when reasoning.
Here's a "step-by-step" of what i've tries:
1.- Load a SPARQL CONSTRUCT on a jena Model
2.- Create a Reasoner and bind it to the Model
3.- Make the Valitidy Report
4.- Print the inferred model
5.- Print the model's size.
Here's the chunk of code there I try to do this:
String construct = "CONSTRUCT { ?s ?p ?o } FROM <http://thesis.com#> WHERE {
?s ?p ?o }";
VirtuosoQueryExecution vqe2 =
VirtuosoQueryExecutionFactory.create(construct, graph);
Model m = vqe2.execConstruct();
Reasoner reasoner = PelletReasonerFactory.theInstance().create();
reasoner = reasoner.bindSchema(m);
InfModel model = ModelFactory.createInfModel(reasoner, m);
ValidityReport rep = model.validate();
printIterator(rep.getReports(), "Validation Reports");
System.out.println(model.size());
Any help will be welcome.
Also, I would like to ask (because I have no person to ask here since this
is the very first Semantic Web related work in my university) if the
architecture i'm planning to develop is the best way to do it. My
dissertation is to develop a Domain-Specific Semantic Web based search
engine. I developed the ontology using Protegé Editor and it's based on the
IEEE and ACM Computer Science Curricula Recommendations. My plan is to
persist the ontology using Virtuoso, retrieve it with jena, make all the
inferences using Pellet and expose all as Web Services, maybe using Joseki,
I Don't know if i'm thinking it well. If anyone can recommend me a better
way i'll be grateful, I don't know if using a database engine like Virtuoso
is too much for this project.
Thanks a lot in advance for taking the time to read this.
--
Israel Felipe Fermín Montilla
http://www.iferminmontilla.net
