Ah okay, case solved. An healthy look into API and this works just fine:
final QueryExecution queryExecution =
>> QueryExecutionFactory.create(QueryFactory.create(queryString),
>
> requestModel);
>
>
>> queryExecution.getContext().set(Symbol.create("TransportSection") ,
>> transportSection);
>
>
My "transportSection" is then available within the QueryContext of the
property function execution.
-- Martin
2011/11/8 Martin Weitzel <[email protected]>
> Hi there,
>
> I am using Jena within a Spring MVC web application as interface for a rdf
> knowledge base. The main application for this knowledge base is to be
> queried with SPARQL for the best fitting (logistic) service provider for a
> certain conext.
>
> I extended the ARQ with a property function, which task is to calculate a
> "fitness" value for each service provider. The problem is, that the
> calculation is depending on information that is only available within the
> requesting query method (i.e. a given transportation path, that is
> needed to calculate the distance from a service provider (stored in the
> knowledge base) to the path (a request-thing)).
>
> So, I am looking for a best practice to pass:
>
> a) The object (reference) itself or
> b) A Key for a ConcurrentMap
>
> to the property function calculating the fitness. I tried to extend the
> SPARQL query by binding a string literal to a new variable, so that it
> would be available in the binding or the context, but without success. My
> current solution is not threadsafe: The FitnessCalculator is registered via
> a factory as shown here (http://jena.sourceforge.net/ARQ/extension.html).
> The factory is a spring service and injects the query service reference to
> the property function. The query method then saves the transport path
> object in a public variable, that is accessable by the Property Function.
> Obviously, this will have side effects in a multi-threaded environment.
>
> I would appreciate any best practice tips!
>
> -- Martin
>
