my code:
String sparqlQueryString8="prefix sumo:" +
"prefix rdf:"+
"select ?c where {?c rdf:type sumo:City }";
OntModel modelcity=ModelFactory.createOntologyModel();
modelcity.read("SUMO.owl");
Query querycity = QueryFactory.create(sparqlQueryString8);
QueryExecution qexeccity = QueryExecutionFactory.create(sparqlQueryString8, modelcity);
ResultSet resultcity = qexeccity.execSelect() ;
for (; resultcity.hasNext();) {
QuerySolution sltcity=resultcity.next();
System.out.println(sltcity.toString());
}
please help me.
First of all, there is a small syntax error in your SPARQL, remove the ";" at the end of the first line. Second, SUMO does not specify a proper URL as ontology identifier (look at SUMO.owl, it contains the following: ). In Jena, the proper prefix then is the file URL, e.g.:
prefix sumo:
If that's not what you want, you could work around using Jena's prefix mapping capabilitites (use something like ParameterizedSparqlString).
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