On 29/04/15 07:06, Claude Warren wrote:
Information I should have provided:

The error occurs at:

Caused by: java.lang.NullPointerException: null
     at
org.apache.jena.n3.N3JenaWriterPP.preparePropertiesForSubject(N3JenaWriterPP.java:257)

FYI - that is the old Turtle-writer and is to be retired.

The RIOT one won't work either.

        Andy


at that line we find
if ( p.getURI().startsWith(RDF.getURI()) ||

since "p" is an anonymous node the getURI() returns null.

Claude

On Tue, Apr 28, 2015 at 10:47 PM, Claude Warren <[email protected]> wrote:

I'm not sure this is an error so I thought I'd see what the consensus is
here before I do anything.

My understanding is that the Graph interface has no restrictions on the
types of objects in the subject, predicate or object.  That is that I could
store an anonymous node as the predicate in a triple even though this is
not allowed in a model.

The FileGraph implementation uses a model internally and when it writes
the data out the model restrictions seem to apply -- that is I can not
store an anonymous node as a predicate.

All other graphs tested thus far allow saving the anonymous node as a
predicate.

It may be that the format of the output is enforcing the restrictions.  I
am currently using a TURTLE format.  However any functional format would be
acceptable.  Is there a way to write the filegraph output when the graph
does not meet the model restrictions?

Claude

--
I like: Like Like - The likeliest place on the web
<http://like-like.xenei.com>
LinkedIn: http://www.linkedin.com/in/claudewarren





Reply via email to