 本体中添加子类后jena中查询没结果
public void test2(){
OntModel student_ontModel1 = ModelFactory.createOntologyModel();
OntDocumentManager dm1 = student_ontModel1.getDocumentManager();
dm1.addAltEntry("http://www.owl-ontologies.com/OntologyStudent.owl", "file:"+"2011.9.5.rdf-xml.owl");
student_ontModel1.read("file:D:/Program Files/Protege_3.4.5/2011.9.5.rdf-xml.owl");
String prefix = "PREFIX owl:<http://www.w3.org/2002/07/owl#>"+
"PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>"+
"PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#>"+
"PREFIX base:<http://www.owl-ontologies.com/OntologyStudent.owl#>";
String select = "select ?sub ";
String where = " where{?sub base:subClassOf base:Student" +
"}";//原来的本体中有Student类，其个体也可查 询，但是添加子类及子类的个体以后，这里就查不出来了，也没有错误提示，但在protege中直接用Sparql查询却可以得到想要的结果。请大家指点 Query query1=QueryFactory.create(prefix + select + where);
QueryExecution qe1 = QueryExecutionFactory.create(query1, student_ontModel1);
ResultSet results1 = qe1.execSelect();
System.out.print(prefix+select+where+"\n");
while(results1.hasNext()){
QuerySolution qs = results1.nextSolution();
System.out.print(qs.get("sub").toString());
System.out.print("\t");
System.out.print("Student");
System.out.print("\n");
}
qe1.close();
}
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2011/9/14 15:20:00
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