2016-10-04 27 views
1

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) ; 
    } 
} 

回答

1

404表示請求了遠程服務器和遠程服務器「未找到」拒絕它。

http://ff-news.ontotext.com/sparql」是某種HTML/webapp頁面。尚不清楚它是否是SPARQL端點。 「查詢鏈接」按鈕顯示一個URL,但是也不起作用。