You are viewing a plain text version of this content. The canonical link for it is here.

Posted to users@jena.apache.org by Eric Scott <er...@att.net> on 2011/08/11 18:18:50 UTC

Null pointer exception with update on named graph.

Hi all -

When I execute this query (taken verbatim from 
http://www.w3.org/Submission/SPARQL-Update/):

"PREFIX dc: <http://purl.org/dc/elements/1.1/>
  INSERT DATA INTO <http://example/bookStore>
  { <http://example/book3>  dc:title  \"Fundamentals of Compiler Design\" }
"

I get a null pointer exception in this context:

   0: 
com.hp.hpl.jena.sparql.core.DatasetGraphCollection.add(DatasetGraphCollection.java:27)
   1: 
com.hp.hpl.jena.sparql.core.DatasetGraphWrapper.add(DatasetGraphWrapper.java:57)
   2: 
com.hp.hpl.jena.sparql.modify.UpdateEngineWorker.visit(UpdateEngineWorker.java:215)
   3: 
com.hp.hpl.jena.sparql.modify.request.UpdateDataInsert.visit(UpdateDataInsert.java:15)
   4: 
com.hp.hpl.jena.sparql.modify.UpdateEngineMain.execute(UpdateEngineMain.java:28)
   5: 
com.hp.hpl.jena.sparql.modify.UpdateProcessorBase.execute(UpdateProcessorBase.java:48)
   6: com.hp.hpl.jena.update.UpdateAction.execute$(UpdateAction.java:319)
   7: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:312)
   8: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:272)
   9: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:226)


Here's a minimal pairing that works just fine:

            "PREFIX dc: <http://purl.org/dc/elements/1.1/>
  INSERT DATA
  { <http://example/book3>  dc:title  \"Fundamentals of Compiler Design\" }
"

I'm new to this. Do I need to somehow declare this named graph 
<http://example/bookStore> before inserting into it?

Versions: Jena 2.6.4, arq 2.8.8.

Any help appreciated!

Regards,

Re: Null pointer exception with update on named graph.

Posted by Eric Scott <er...@att.net>.

Apologies for this. I sent this before subscribing to the list. Please 
see my other post 'null pointer exception when inserting into a named 
graph', which is a better statement of the problem.

- ES

On 08/11/2011 09:18 AM, Eric Scott wrote:
> Hi all -
>
> When I execute this query (taken verbatim from 
> http://www.w3.org/Submission/SPARQL-Update/):
>
> "PREFIX dc: <http://purl.org/dc/elements/1.1/>
>  INSERT DATA INTO <http://example/bookStore>
>  { <http://example/book3>  dc:title  \"Fundamentals of Compiler 
> Design\" }
> "
>
> I get a null pointer exception in this context:
>
>   0: 
> com.hp.hpl.jena.sparql.core.DatasetGraphCollection.add(DatasetGraphCollection.java:27)
>   1: 
> com.hp.hpl.jena.sparql.core.DatasetGraphWrapper.add(DatasetGraphWrapper.java:57)
>   2: 
> com.hp.hpl.jena.sparql.modify.UpdateEngineWorker.visit(UpdateEngineWorker.java:215)
>   3: 
> com.hp.hpl.jena.sparql.modify.request.UpdateDataInsert.visit(UpdateDataInsert.java:15)
>   4: 
> com.hp.hpl.jena.sparql.modify.UpdateEngineMain.execute(UpdateEngineMain.java:28)
>   5: 
> com.hp.hpl.jena.sparql.modify.UpdateProcessorBase.execute(UpdateProcessorBase.java:48)
>   6: com.hp.hpl.jena.update.UpdateAction.execute$(UpdateAction.java:319)
>   7: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:312)
>   8: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:272)
>   9: com.hp.hpl.jena.update.UpdateAction.execute(UpdateAction.java:226)
>
>
> Here's a minimal pairing that works just fine:
>
>            "PREFIX dc: <http://purl.org/dc/elements/1.1/>
>  INSERT DATA
>  { <http://example/book3>  dc:title  \"Fundamentals of Compiler 
> Design\" }
> "
>
> I'm new to this. Do I need to somehow declare this named graph 
> <http://example/bookStore> before inserting into it?
>
> Versions: Jena 2.6.4, arq 2.8.8.
>
> Any help appreciated!
>
> Regards,
>
>
>
>
>