> Dear friends of jena community,
I am testing the syntax of apache jena rules, with a very simple example, where I create the following model and classes: OntModel m = ModelFactory.createOntologyModel(); OntClass c0 = m.createClass( NS + "c0" ); OntClass c1 = m.createClass( NS + "c1" ); OntClass c2 = m.createClass( NS + "c2" ); and the following individuals as members of the its respective classes: //creation of individual Individual i0 = m.createIndividual( NS + "individual0", c0 ); Individual i1 = m.createIndividual( NS + "individual1", c1 ); when I run the rule, that says: if individual* i? *is member of c0, then has to be member of *c2* String *ruleSrc* = "[rule1: (?a http://www.w3.org/1999/02/22-rdf-syntax-ns#type www.example.com#c0) -> " + "(?a http://www.w3.org/1999/02/22-rdf-syntax-ns#type www.example.com#c2) ]"; the rule is triggered as expected and give me the following result: [www.example.com#individual0, http://www.w3.org/1999/02/22-rdf-syntax-ns#type, www.example.com#c2]> Nevertheless, when I add more information to the model, and say that individuals i0 and i1 have birthday: i0.addProperty(born_in, date1.toString()); i1.addProperty(born_in, date2.toString()); The behavior of rule output changed, and I obtain a different result: <ModelCom org.apache.jena.reasoner.rulesys.impl [ www.example.com#individual1, http://www.w3.org/1999/02/22-rdf-syntax-ns#type, www.example.com#c2] [www.example.com#individual0, http://www.w3.org/1999/02/22-rdf-syntax-ns#type, www.example.com#c2]> Where individual 1 is declared as member of c2, it means that individual1 is member of c0, something that I did not declared. I changed model declaration as follows: OntModel m = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM); and obtained the expected result, however the documentation says there is not reasoning there, thus I implemented a reasoner model and obtained an unexpected result again. My main concern is that when I inspect the *asserted model , *I see it contains individual 1 declared as part of c0, something that, according to my understanding should not occur, because I have not declared that. Any comment and recommendation is welcomed. Bellow is the whole java code. Luis Ramos ****************************************CODE ********************************************** import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.List; import org.apache.jena.ontology.DatatypeProperty; import org.apache.jena.ontology.Individual; import org.apache.jena.ontology.OntClass; import org.apache.jena.ontology.OntModel; import org.apache.jena.ontology.OntModelSpec; import org.apache.jena.rdf.model.InfModel; import org.apache.jena.rdf.model.Model; import org.apache.jena.rdf.model.ModelFactory; import org.apache.jena.reasoner.Reasoner; import org.apache.jena.reasoner.rulesys.GenericRuleReasoner; import org.apache.jena.reasoner.rulesys.Rule; import org.apache.jena.vocabulary.XSD; public class OntGenRule { public static void main(String[] args) throws ParseException { String URL = "www.example.com"; String NS = URL+"#"; String rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns";; String rdf_ns = rdf+"#"; //creation of the model OntModel m = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM); //addition of classes OntClass c0 = m.createClass( NS + "c0" ); OntClass c1 = m.createClass( NS + "c1" ); OntClass c2 = m.createClass( NS + "c2" ); //creation of individual Individual i0 = m.createIndividual( NS + "individual0", c0 ); Individual i1 = m.createIndividual( NS + "individual1", c1 ); //date property DatatypeProperty born_in = m.createDatatypeProperty( NS + "birthday" ); born_in.addDomain( m.getOntClass( NS + "c0" ) ); born_in.addDomain( m.getOntClass( NS + "c1" ) ); born_in.addRange( XSD.dateTime ); //create a date SimpleDateFormat sdf = new SimpleDateFormat("dd-M-yyyy hh:mm:ss");//-uncomment for test String date1toString = "31-08-1982 10:20:56";//-uncomment for test String date2toString = "12-02-1977 10:20:56";//-uncomment for test Date date1 = sdf.parse(date1toString);//-uncomment for test Date date2 = sdf.parse(date2toString);//-uncomment for test //addition of date to individuals i0.addProperty(born_in, date1.toString());//-uncomment for test i1.addProperty(born_in, date2.toString());//-uncomment for test //System.out.println(p0.getProperty(born_in).getObject()); //System.out.println(p1.getProperty(born_in).getObject()); OntModel testModel = ModelFactory.createOntologyModel(OntModelSpec.OWL_DL_MEM_RULE_INF, m);//onto model, to hold ontology String ruleSrc = "[rule1: (?a http://www.w3.org/1999/02/22-rdf-syntax-ns#type www.example.com#c0) -> " + "(?a http://www.w3.org/1999/02/22-rdf-syntax-ns#type www.example.com#c2) ]"; List rules = Rule.parseRules(ruleSrc); Reasoner reasoner = new GenericRuleReasoner(rules); InfModel inf = ModelFactory.createInfModel(reasoner, testModel); Model deducedM = ModelFactory.createOntologyModel(); deducedM = inf.getDeductionsModel(); System.out.println(testModel); System.out.println(deducedM); } }
