Hello Dave, though I have Student class in my owl and GoodStudent as the
subclass of Student but this statement gives me error and does not
recognize GoodStudent.
for (Iterator i = inf.listResourcesWithProperty(RDF.type, *GoodStudent*);
i.hasNext();) {
System.out.println("Good student: " + i.next());
On Sun, Sep 18, 2016 at 1:36 PM, javed khan <[email protected]> wrote:
> Thanks a lot Dave, let me try it. I hope it will help.
>
> Regards
>
> On Sun, Sep 18, 2016 at 1:28 PM, Dave Reynolds <[email protected]>
> wrote:
>
>> On 18/09/16 21:24, javed khan wrote:
>>
>>> Thanks Lorenz and Dave, I have corrected the
>>> http://www.semanticweb.org#
>>> <http://www.semanticweb.org/#GPA>Student to ?x but it does not
>>> work.Actually it does not save the updated marks/GPA of student and when
>>> I
>>> remove the Jena rules part, it then updates and save the GPA.
>>> I also try the SPARQL query inside Protege Query tab but it does not give
>>> me any instance of the GoodStudent class.
>>>
>>
>> The example I showed does work. If you write inf to file or std out you
>> can see the class, if you run your sparql query it lists s1.
>>
>> Dave
>>
>>
>> On Sun, Sep 18, 2016 at 12:40 PM, Lorenz Buehmann <
>>> [email protected]> wrote:
>>>
>>> The second condition of your rule doesn't make any sense as the subject
>>>> is Student and it should be ?x.
>>>>
>>>>
>>>> On 18.09.2016 17:41, javed khan wrote:
>>>>
>>>>> This code does not work. I want to save student marks/GPA in the file
>>>>> and
>>>>> based on GPA assign students to GoodStudent or WorstStudents sub
>>>>> classes
>>>>>
>>>> of
>>>>
>>>>> Student via Jena rules.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> OntModel model=ModelFactory.createOntologyModel();
>>>>>
>>>>> InputStream in =FileManager.get().open("C://std.owl");
>>>>> if (in==null) {
>>>>> throw new IllegalArgumentException( "File: " + " not
>>>>> found");
>>>>> } model.read(in,"");
>>>>>
>>>>> String ns="http://www.semanticweb.org#";;
>>>>>
>>>>> OntClass user1 = model.getOntClass(ns + "Student");
>>>>>
>>>>> Individual indiv = user1.createIndividual(ns + name); //name
>>>>>
>>>> is
>>>>
>>>>> variable
>>>>>
>>>>> Property prop= model.getProperty(ns,"GPA");
>>>>>
>>>>> indiv.addLiteral(prop, marks); //marks also variable having
>>>>> some value i-e 3.0
>>>>>
>>>>>
>>>>>
>>>>> String rule="[rule1:(?x http://www.w3.org/1999/02/22-
>>>>>
>>>> rdf-syntax-ns#type
>>>>
>>>>> http://www.semanticweb.org#Student) " +
>>>>> "( http://www.semanticweb.org#Student
>>>>> http://www.semanticweb.org#GPA ?marks + )" + "greaterThan(?marks,
>>>>>
>>>> 2) "+
>>>>
>>>>> " -> (?x http://www.w3.org/1999/02/22-rdf-syntax-ns#type
>>>>> http://www.semanticweb.org#GoodStudent )]";
>>>>>
>>>>> String queryString= "PREFIX std:<http://www.semanticweb.
>>>>>
>>>> org#>
>>>>
>>>>> "+
>>>>> "PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#> " +
>>>>> "PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> "+
>>>>> "SELECT * " +
>>>>> " WHERE { ?x rdf:type std:GoodStudent}";
>>>>>
>>>>> Reasoner reasoner2 = new
>>>>> GenericRuleReasoner(Rule.parseRules(rule));
>>>>> InfModel inf = ModelFactory.createInfModel(reasoner2, model);
>>>>> Query query = QueryFactory.create(queryString);
>>>>> QueryExecution qe = QueryExecutionFactory.create(query,
>>>>> inf);
>>>>> ResultSet results = qe.execSelect();
>>>>> ResultSetFormatter.out(System.out, results, query);
>>>>> qe.close();
>>>>>
>>>>>
>>>>>
>>>>> try (FileOutputStream writer = new
>>>>> FileOutputStream("C://std.owl")) {
>>>>> model.write(writer, "RDF/XML");
>>>>> } catch (IOException ex) {
>>>>> Logger.getLogger(stdinfo.class
>>>>> .getName()).log(Level.SEVERE,
>>>>> null, ex);
>>>>> }
>>>>> model.write(System.out, "N3");
>>>>>
>>>>> }
>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>
