problem on creating classes with Jena

[朱曼 <zh...@gmail.com>]

Hi all,

I have a problem on creating classes with Jena. I created an anonymous
OntClass with OntClass con = model.createClass(), and I want this class to
be existancial restricted like "exists property.owlthing", how should I
further modify this OntClass con?

Many thanks!

All my best!

June

Re: problem on creating classes with Jena

[Ian Dickinson <ia...@epimorphics.com>]

Hi June,
On 27/04/11 05:50, 朱曼 wrote:
> I have a problem on creating classes with Jena. I created an anonymous
> OntClass with OntClass con = model.createClass(), and I want this class to
> be existancial restricted like "exists property.owlthing", how should I
> further modify this OntClass con?

If you want to create a new class description, use the various 
createXXRestriction methods in OntModel, e.g: http://goo.gl/R6CLI

If instead you have an existing resource denoting an owl:Class, and you 
want to change it to be an owl:Restriction, you can use the 
convertToRestriction() method on OntClass, and subsequently the various 
convertToXXRestriction methods on Restriction.

Failing that, you can just add the triple you need directly to the 
model, since all state in an OntModel is contained in the model itself, 
not in the various OntClass, etc, wrapper classes.

Please note that Jena doesn't yet support OWL 2.0 specific restriction 
types with convenience classes, though you can of course add the 
necessary triples to the model.

Ian




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