我正在使用Jena向遠程端點發送SPARQL查詢。這適用於大多數端點。但是,它並不適用於我需要的http://ff-news.ontotext.com/sparql,因爲它提供了HttpException: 404
。但是,代碼適用於DBpedia
和許多其他端點。Jena查詢特定遠程SPARQL端點引發HttpException:404
這裏是我的代碼:
import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.ResultSet;
import org.apache.jena.query.ResultSetFormatter;
import org.apache.jena.rdf.model.NodeIterator;
import org.apache.jena.rdf.model.RDFNode;
import at.jku.dke.hilal.analysis_graphs.DimensionsToAnalysisSituation;
import at.jku.dke.hilal.md_elements.Dimension;
import at.jku.dke.hilal.owl_handler.BasicOWLHandler;
import org.apache.jena.graph.NodeFactory;
import org.apache.jena.graph.Triple;
import org.apache.jena.ontology.Individual;
import org.apache.jena.graph.Node;
import org.apache.jena.sparql.syntax.ElementTriplesBlock;
public class SparqlQuery extends Query {
public static void main (String [] args){
String queryString = "select distinct ?Concept where {[] a ?Concept} LIMIT 10";
Query query = QueryFactory.create(queryString) ;
System.out.println(queryString);
QueryExecution qexec = QueryExecutionFactory.sparqlService("http://ff-news.ontotext.com/sparql", query);
ResultSet results = qexec.execSelect();
ResultSetFormatter.out(System.out, results, query) ;
}
}