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Posted to users@jena.apache.org by 朱曼 <mz...@seu.edu.cn> on 2011/04/30 07:05:48 UTC
problem on using jena to create ontology classes
Dear all,
Hi!
Currently I am using Jena to process ontology and create ontology classes.
But I confront a problem: how can I create a class which is existentially
restricted by the inverse of an existed property(hasValue inverseOf
Property)? I tried "property.getInverse()", but I get a
NullPointerException, I think that is because the inverse property doesn't
really exist in the current ontology. And I also notice there is a
createInverseFunctionalProperty method in OntModel, but how can I create an
inverse property based on an existed property, so far as the
createInverseFunctionalProperty method only have "uri" and "functional"
parameters?
Thanks very much for your time and help!
All my best!
Yours,
June
Re: problem on using jena to create ontology classes
Posted by Ian Dickinson <ia...@epimorphics.com>.
On 01/05/11 21:28, Dave Reynolds wrote:
> On Sat, 2011-04-30 at 13:05 +0800, 朱曼 wrote:
>> Currently I am using Jena to process ontology and create ontology classes.
>> But I confront a problem: how can I create a class which is existentially
>> restricted by the inverse of an existed property(hasValue inverseOf
>> Property)? I tried "property.getInverse()", but I get a
>> NullPointerException, I think that is because the inverse property doesn't
>> really exist in the current ontology. And I also notice there is a
>> createInverseFunctionalProperty method in OntModel, but how can I create an
>> inverse property based on an existed property, so far as the
>> createInverseFunctionalProperty method only have "uri" and "functional"
>> parameters?
>
> You want OntProperty#addInverseOf
Or OntProperty#setInverseOf, which will replace any existing
owl:inverseOf assertions for that property.
> (not sure why it is called "add.."
> rather than "create..")
Because that call is only adding an owl:inverseOf triple, not creating
the inverse property itself. To actually create the property which is
the inverse of the property in question, June would need a separate
OntModel#createObjectProperty method call. Perhaps there could be a
shortcut method which performs both steps in one go, but currently there
isn't.
Ian
--
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cell: +44-7786-850536 landline: +44-1275-399069
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Portishead, Bristol BS20 6PT, UK
Re: problem on using jena to create ontology classes
Posted by Dave Reynolds <da...@gmail.com>.
On Sat, 2011-04-30 at 13:05 +0800, 朱曼 wrote:
> Dear all,
>
> Hi!
>
> Currently I am using Jena to process ontology and create ontology classes.
> But I confront a problem: how can I create a class which is existentially
> restricted by the inverse of an existed property(hasValue inverseOf
> Property)? I tried "property.getInverse()", but I get a
> NullPointerException, I think that is because the inverse property doesn't
> really exist in the current ontology. And I also notice there is a
> createInverseFunctionalProperty method in OntModel, but how can I create an
> inverse property based on an existed property, so far as the
> createInverseFunctionalProperty method only have "uri" and "functional"
> parameters?
You want OntProperty#addInverseOf (not sure why it is called "add.."
rather than "create..")
Dave