Jena 中的具体化和 SPARQL*：兼容性

如何解决Jena 中的具体化和 SPARQL*：兼容性

我可以使用 SPARQL* 查询来查询使用具体化的经典 RDF 模型吗？ 对我来说，Jena documentation 在这里有点含糊。

下面的代码创建了一个具体化的语句：

<< <http://www.mysubject.com> <http://www.mypredicate.com> <http://www.myobject.com> >> <http://www.sayed.de#sayed> <http://www.sayer.de> .

该代码进一步包含两个查询：(i) 一个经典的 SPARQL 查询，(ii) 一个 SPARQL* 查询。 结果都查询 <http://www.sayer.de>。虽然 (i) 返回了解决方案，但 (ii) 没有这样做。

我在做什么/理解错了什么？

import org.apache.jena.ontology.DatatypeProperty;
import org.apache.jena.ontology.OntModel;
import org.apache.jena.ontology.OntModelSpec;
import org.apache.jena.query.*;
import org.apache.jena.rdf.model.*;

import java.io.StringWriter;

public class RdfStar {

    public static void main(String[] args) {

        // let's create an ontModel and fill it with data:
        OntModel model =  ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
        ReifiedStatement s = model.createReifiedStatement(
                model.createStatement(
                        ResourceFactory.createResource("http://www.mysubject.com"),ResourceFactory.createProperty("http://www.mypredicate.com"),ResourceFactory.createResource("http://www.myobject.com"))
        );
        ObjectProperty sayedProperty = model.createObjectProperty("http://www.sayed.de#sayed");
        s.addProperty(sayedProperty,model.createResource("http://www.sayer.de"));

        // write to console
        StringWriter myWriter = new StringWriter();
        model.write(myWriter,"NT");
        String result = myWriter.toString();
        System.out.println(result);

        // Now let's create a regular query
        String queryString = "SELECT ?who WHERE {" +
                "?statement <http://www.sayed.de#sayed> ?who ." +
                "}";
        Query query = QueryFactory.create(queryString) ;
        try (QueryExecution qexec = QueryExecutionFactory.create(query,model)) {
            ResultSet results = qexec.execSelect();
            while (results.hasNext()) {
                QuerySolution soln = results.nextSolution();
                RDFNode x = soln.get("who");
                System.out.println(x);
            }
        } catch (Exception e){
            e.printstacktrace();
        }

        // Now SPARQL STAR

        queryString = "SELECT ?who WHERE {" +
                "<< ?a ?b ?c >> ?d ?who ." +
                "}";
        query = QueryFactory.create(queryString,Syntax.SyntaxARQ) ;
        try (QueryExecution qexec = QueryExecutionFactory.create(query,model)) {
            ResultSet results = qexec.execSelect();
            while (results.hasNext()) {
                QuerySolution soln = results.nextSolution();
                RDFNode x = soln.get("who");
                System.out.println("Star result: " + x);
            }
        } catch (Exception e){
            e.printstacktrace();
        }
    }
}