ResultSet iterations duration

[Jérôme]

Hi all,

I am currently working with Jena and Fuseki. My web application queries 
the remote fuseki server with a
"QueryExecutionFactory.sparqlService(url, query)" call.
The server answers quickly, but the resultSet iteration is really slow.


            QueryExecution qExec = 
QueryExecutionFactory.sparqlService(url, query);
            ResultSet set = qExec.execSelect();
            log.info("start");
            while (set.hasNext()) {
                set.next();
            }
            log.info("done");

between 2 and 6 seconds from "start" to "done".

1-Why is it so long? How can i boost it?
2-Is there a way to know the number of solutions without iterate over 
the resultSet?

Thanks.

Jérôme.