Dear Pan, did you try add namespace declarations into your query?
Best regards Max Am Mo., 11. März 2024 um 14:45 Uhr schrieb Anna P < [email protected]>: > Dear Jena support team, > > Currently I just started to work on a SPARQL project using Jena and I could > not get a solution when I query a model. > I imported a turtle file and ran a simple query, and the snippet code is > shown below. However, I got the error. > > public class App { > public static void main(String[] args) { > try { > Model model = RDFDataMgr.loadModel('data.ttl', Lang.TURTLE); > RDFDataMgr.write(System.out, model, Lang.TURTLE); > String queryString = "SELECT * { ?s ?p ?o }"; > Query query = QueryFactory.create(queryString); > QueryExecution qe = QueryExecutionFactory.create(query, model); > ResultSet results = qe.execSelect(); > ResultSetFormatter.out(System.out, results, query); > qe.close(); > } catch (Exception e) { > e.printStackTrace(); > } > } > } > > Here is the error message: > > org.apache.jena.riot.RiotException: Not registered as a SPARQL result set > output syntax: Lang:SPARQL-Results-JSON > at > > org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:179) > at > > org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:156) > at > > org.apache.jena.sparql.resultset.ResultsWriter.write(ResultsWriter.java:149) > at > > org.apache.jena.sparql.resultset.ResultsWriter$Builder.write(ResultsWriter.java:96) > at > > org.apache.jena.query.ResultSetFormatter.output(ResultSetFormatter.java:308) > at > > org.apache.jena.query.ResultSetFormatter.outputAsJSON(ResultSetFormatter.java:516) > at de.unistuttgart.ki.esparql.App.main(App.java:46) > > > Thank you for your time and help! > > Best regards, > > Pan >
