将 Hermit 与 ONT-API 和 SPARQL 查询结合使用

如何解决将 Hermit 与 ONT-API 和 SPARQL 查询结合使用

我正在使用 owl-api 通过 swrl 规则加载和 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器：

import org.semanticweb.hermit.reasonerFactory;

OWLreasonerFactory reasonerFactory = new reasonerFactory();
OWLreasoner reasoner = reasonerFactory.createreasoner(ontologyWithRules);

最后，我想查询这个模型：

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());
    }
}

但是没有使用推理器。有没有办法在打开推理器的情况下在图形上使用 SPARQL 查询？

解决方法

对模型运行推理是缺失的一步。因此，我需要使用 InferredOntologyGenerator 类。

一行代码说一千多字：

/** 
* 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());
    }
}