将Hermit与ONT-API和SPARQL查询结合使用

Question

我正在使用OWL-API加载带有SWRL规则的owl本体。

我用以下代码加载了一个本体：

IRI iri = IRI.create(BASE_URL);
OntologyManager manager = OntManagers.createManager();
// Load an ontology
Ontology ontologyWithRules = manager.loadOntologyFromOntologyDocument(iri);

然后我实例化一个隐士推理者：

import org.semanticweb.HermiT.ReasonerFactory;

OWLReasonerFactory reasonerFactory = new ReasonerFactory();
OWLReasoner reasoner = reasonerFactory.createReasoner(ontologyWithRules);

最后，我想查询一下这个模型：

try (
    QueryExecution qexec = QueryExecutionFactory.create(QueryFactory
        .create("SELECT ?s ?p ?o WHERE {  ?s ?p ?o }"), ontologyWithRules.asGraphModel())
) {
    ResultSet res = qexec.execSelect();
    while (res.hasNext()) {
        System.out.println(res.next());
    }
}

然而，推理机并没有被使用。有没有一种方法可以在打开推理的情况下在图上使用SPARQL查询？

Answer 1

在模型上运行推理是缺失的一步。因此，我需要使用InferredOntologyGenerator类。

一行代码胜过千言万语：

/** 
* Important imports:
* import org.semanticweb.HermiT.ReasonerFactory;
* import org.semanticweb.owlapi.util.InferredOntologyGenerator;
**/

IRI iri = IRI.create(BASE_URL);
OntologyManager manager = OntManagers.createManager();
// Load an ontology
Ontology ontologyWithRules = manager.loadOntologyFromOntologyDocument(iri);

// Instantiate a Hermit reasoner:
OWLReasonerFactory reasonerFactory = new ReasonerFactory();
OWLReasoner reasoner = reasonerFactory.createReasoner(ontologyWithRules);

OWLDataFactory df = manager.getOWLDataFactory();

// Create an inference generator over Hermit reasoner
InferredOntologyGenerator inference = new  InferredOntologyGenerator(reasoner);

// Infer
inference.fillOntology(df, ontologyWithRules);

// Query
try (
    QueryExecution qexec = QueryExecutionFactory.create(QueryFactory
        .create("SELECT ?s ?p ?o WHERE { ?s ?p ?o } "), ontologyWithRules.asGraphModel())
) {
    ResultSet res = qexec.execSelect();
    while (res.hasNext()) {
        System.out.println(res.next());
    }
}