model.isEmpty() should be enough:
http://jena.apache.org/documentation/javadoc/jena/com/hp/hpl/jena/rdf/model/Model.html#isEmpty()
On Mon, Mar 2, 2015 at 6:58 PM, Maarten van Dessel
<maarten.vandes...@ugent.be> wrote:
> I'm sorry for the inconvenience, it was a mistake on my end.
> Apparently " model.listStatements.hasNext() " does seem to test correctly if
> a model is empty.
>
>
>> Op 2-mrt.-2015, om 18:04 heeft Martynas Jusevičius <marty...@graphity.org>
>> het volgende geschreven:
>>
>> What's the query code? You are probably querying from an inferencing
>> model that imports example.com ontology.
>>
>> On Mon, Mar 2, 2015 at 4:58 PM, Maarten van Dessel
>> <maartenvandes...@hotmail.com> wrote:
>>> Hi everyone,
>>>
>>> I'm using construct queries in a project. I want to make decisions based on
>>> wether the constructed model contains any data. Is there any way on how
>>> this can be known?
>>>
>>> Example query:
>>> CONSTRUCT
>>> { ?person <http://example.com#hasStatus> <http://example.com#Occupied> .}
>>> WHERE
>>> { ?person <http://example.com#hasStatus> <http://example.com#Free> .}
>>>
>>> Printing the resulting model (which seems empty):
>>> <rdf:RDF
>>> xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
>>> xmlns:owl="http://www.w3.org/2002/07/owl#";
>>> xmlns:example="http://example.com#";
>>> xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#";
>>> xmlns:xsd="http://www.w3.org/2001/XMLSchema#"; >
>>> </rdf:RDF>
>>>
>>> My attempt to check wether a model is empty:
>>> StmtIterator nodeIterator = model.listStatements();
>>> if (nodeIterator.hasNext()) {
>>> // do something
>>> }
>>>
>>> This however doesn't work, since there are still triples returned in the
>>> iterator:
>>> [http://example.com#hasStatus,
>>> http://www.w3.org/1999/02/22-rdf-syntax-ns#type,
>>> http://www.w3.org/2002/07/owl#ObjectProperty]
>>>
>>> Any thoughts are appreciated.
>>>
>>> Thanks,
>>>
>>> Maarten
>
