Local sparql endpoint (Loading an n-triples file in jena TDB)

Asked Mar 11 '16 at 14:03

Active Mar 11 '16 at 17:29

Viewed 258 times

I'm new with using Jena TDB with Java. I'm trying to load an .nt file to create a local sparql endpoint to be able to send locally sparql queries.

This is where I got so far :

public static final String tdbDirectory = "D:\\TDB";
public static final String dbdump = "D:\\RDFdump.nt"; 
...

Dataset tdbModel =  TDBFactory.createDataset(tdbDirectory);    
FileManager.getModel().read(dbdump, tdbDirectory, "N-TRIPLES");


String q = "SELECT DISTINCT * WHERE { ?s ?p ?o } LIMIT 10";

Query query = QueryFactory.create(q);

QueryExecution qexec = QueryExecutionFactory.create(query, tdbModel);
ResultSet results2 = qexec.execSelect();
...

But this shows me the following error:

Exception in thread "main" java.lang.NullPointerException

Please, can anyone help me with the issue or help me understand the correct way to load locally an .nt file as a sparql endpoint using Jena TDB and Java? I tried a couple of things but I'm a bit lost.

edited Mar 11 '16 at 14:19

asked Mar 11 '16 at 14:03

ichmode

1

Without seeing the line number where the exception occurs it's impossible. But one of the objects your invoking a method on is `null` that's all. Please post the stack trace. – UninformedUser Mar 11 '16 at 14:55
The exception points to this line : FileManager.getModel().read(dbdump, tdbDirectory, "N-TRIPLES"); – ichmode Mar 11 '16 at 14:57
Please, which object is null? – ichmode Mar 11 '16 at 14:59
1

Again, please post the whole stack trace. – UninformedUser Mar 11 '16 at 21:21

Local sparql endpoint (Loading an n-triples file in jena TDB)

0 Answers0