Hi,
how did you setup your project? Which Jena version? Do you use Maven?
Which dependencies? It looks like ARQ.init() hasn't been called which
should happen automatically if the setup of the project is correct.
Cheers,
Lorenz
On 11.03.24 14:44, Anna P wrote:
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
--
Lorenz Bühmann
Research Associate/Scientific Developer
Email buehm...@infai.org
Institute for Applied Informatics e.V. (InfAI) | Goerdelerring 9 | 04109
Leipzig | Germany
