Problem with Tutorial11.java from "An Introduction to RDF and the Jena RDF API”

[Panián Pazán <pa...@gmail.com>]

Hi,

I’ve just started learning Jena, so I’ve been doing the tutorials I've
found at “An Introduction to RDF and the Jena RDF API”
<http://jena.apache.org/tutorials/rdf_api.html>. Everything was working
fine until I got into Tutorial11. The last part of the code:

// create an empty graph
model = ModelFactory.createDefaultModel();

 // create the resource
Resource r = model.createResource();

// add the property
r.addProperty(RDFS.label, "11")
 .addLiteral(RDFS.label, 11);

// write out the graph
model.write( System.out, "N-TRIPLE");

It’s supposed to produce this output:

_:A... <http://www.w3.org/2000/01/rdf-schema#label> "11" .

But what I get after running it is:

_:B… <http://www.w3.org/2000/01/rdf-schema#label> "11"^^<
http://www.w3.org/2001/XMLSchema#long> .
_:B… <http://www.w3.org/2000/01/rdf-schema#label> "11" .

So they are different literals.

Did I misunderstood anything? Am I doing something different as expected?
I’m using IntelliJ IDEA 2018.2.2 Ultimate edition.

I don’t know if this is the right list to notify it but I think there is
also a typo in that part of the page “An Introduction to RDF and the Jena
RDF API” <http://jena.apache.org/tutorials/rdf_api.html>. The code that
appears there is:

// create the resource
Resource r = model.createResource();

// add the property
r.addProperty(RDFS.label, "11")
 .*addProperty*(RDFS.label, 11);

// write out the Model
model.write(system.out, "N-TRIPLE");

But in the Tutorial11.java the correspondent (working) code is:

 // create the resource
 r = model.createResource();

// add the property
r.addProperty(RDFS.label, "11")
 .*addLiteral*(RDFS.label, 11);

// write out the graph
model.write( System.out, "N-TRIPLE");

Thanks in advance!!
 Panian.

Re: Problem with Tutorial11.java from "An Introduction to RDF and the Jena RDF API”

[Panián Pazán <pa...@gmail.com>]

Yeahp...

Looks like it's something wrong in the turorial. Indeed, according to
Jena's JavaDoc, is the paragraph preceding the code also wrong?

"Jena's interfaces also support typed literals. The old-fashioned way
(shown below) treats typed literals as shorthand for strings: *typed values
are converted in the usual Java way to strings and these strings are stored
in the Model*. For example, try (noting that for simple literals, we can
omit the model.createLiteral(...) call):"

Thanks!!
 Panian.



El mar., 25 sept. 2018 a las 7:43, Lorenz B. (<
buehmann@informatik.uni-leipzig.de>) escribió:

>
>
> > // add the property
> > r.addProperty(RDFS.label, "11")
> >  .addLiteral(RDFS.label, 11);
> I'm wondering whether the tutorial is correct here given the fact that
> the method addLiteral will handle argument 11 in the second call as a
> proper number and thus create a typed literal of type xsd:long, see [1]
>
> [1]
>
> https://jena.apache.org/documentation/javadoc/jena/org/apache/jena/rdf/model/Resource.html#addLiteral-org.apache.jena.rdf.model.Property-long-
>
> --
> Lorenz Bühmann
> AKSW group, University of Leipzig
> Group: http://aksw.org - semantic web research center
>
>

Re: Problem with Tutorial11.java from "An Introduction to RDF and the Jena RDF API”

["Lorenz B." <bu...@informatik.uni-leipzig.de>]

> // add the property
> r.addProperty(RDFS.label, "11")
>  .addLiteral(RDFS.label, 11);
I'm wondering whether the tutorial is correct here given the fact that
the method addLiteral will handle argument 11 in the second call as a
proper number and thus create a typed literal of type xsd:long, see [1]

[1]
https://jena.apache.org/documentation/javadoc/jena/org/apache/jena/rdf/model/Resource.html#addLiteral-org.apache.jena.rdf.model.Property-long-

-- 
Lorenz Bühmann
AKSW group, University of Leipzig
Group: http://aksw.org - semantic web research center