我正在使用Protege OWL API 4.3(OWL API 3.4.2)。
它安装了HermiT Reasoner插件。
我的问题是,无论我对推理机的查询如何,都没有输出,它不提供任何实例。
这是我的本体的样子:
<Ontology xmlns="http://www.w3.org/2002/07/owl#"
xml:base="http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:xml="http://www.w3.org/XML/1998/namespace"
ontologyIRI="http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17">
<Prefix name="" IRI="http://www.w3.org/2002/07/owl#"/>
<Prefix name="owl" IRI="http://www.w3.org/2002/07/owl#"/>
<Prefix name="rdf" IRI="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<Prefix name="xsd" IRI="http://www.w3.org/2001/XMLSchema#"/>
<Prefix name="rdfs" IRI="http://www.w3.org/2000/01/rdf-schema#"/>
<Declaration>
<Class IRI="#Person"/>
</Declaration>
<Declaration>
<Class IRI="#PersonWithPosition1"/>
</Declaration>
<Declaration>
<DataProperty IRI="#position"/>
</Declaration>
<Declaration>
<NamedIndividual IRI="#mary"/>
</Declaration>
<Declaration>
<NamedIndividual IRI="#peter"/>
</Declaration>
<EquivalentClasses>
<Class IRI="#PersonWithPosition1"/>
<ObjectIntersectionOf>
<Class IRI="#Person"/>
<DataHasValue>
<DataProperty IRI="#position"/>
<Literal datatypeIRI="http://www.w3.org/2001/XMLSchema#integer">1</Literal>
</DataHasValue>
</ObjectIntersectionOf>
</EquivalentClasses>
<SubClassOf>
<Class IRI="#PersonWithPosition1"/>
<Class IRI="#Person"/>
</SubClassOf>
<ClassAssertion>
<Class IRI="#Person"/>
<NamedIndividual IRI="#mary"/>
</ClassAssertion>
<ClassAssertion>
<Class IRI="#Person"/>
<NamedIndividual IRI="#peter"/>
</ClassAssertion>
<DataPropertyAssertion>
<DataProperty IRI="#position"/>
<NamedIndividual IRI="#mary"/>
<Literal datatypeIRI="http://www.w3.org/2001/XMLSchema#int">1</Literal>
</DataPropertyAssertion>
<DataPropertyAssertion>
<DataProperty IRI="#position"/>
<NamedIndividual IRI="#peter"/>
<Literal datatypeIRI="http://www.w3.org/2001/XMLSchema#int">2</Literal>
</DataPropertyAssertion>
<DataPropertyDomain>
<DataProperty IRI="#position"/>
<Class IRI="#Person"/>
</DataPropertyDomain>
<DataPropertyRange>
<DataProperty IRI="#position"/>
<Datatype abbreviatedIRI="xsd:int"/>
</DataPropertyRange>
这是我的代码:
public class OWLAPIDemoApplication {
public static void main(String[] args) {
OWLOntologyManager manager = OWLManager.createOWLOntologyManager();
try {
OWLOntology ontology;
File file = new File("ontology.owl");
ontology = manager.loadOntologyFromOntologyDocument(file);
System.out.println("Loaded ontology: " + ontology);
// Create an HermiT reasoner.
Reasoner reasoner = new Reasoner(ontology);
OWLDataFactory factory = manager.getOWLDataFactory();
PrefixManager pm = new DefaultPrefixManager("#");
// Get reference to the class PersonWithinPosition1
OWLClass person = factory.getOWLClass(":Person", pm);
OWLDataProperty position = factory.getOWLDataProperty(":position",
pm);
OWLClassExpression query = factory.getOWLObjectIntersectionOf(
person,
factory.getOWLDataHasValue(position,
factory.getOWLLiteral(1)));
// Create a fresh name for the query.
OWLClass newName = factory.getOWLClass(IRI.create("temp001"));
// Make the query equivalent to the fresh class
OWLAxiom definition = factory.getOWLEquivalentClassesAxiom(newName,
query);
manager.addAxiom(ontology, definition);
manager.saveOntology(ontology, new SystemOutDocumentTarget());
reasoner.flush();
NodeSet<OWLNamedIndividual> w = reasoner
.getInstances(newName, true);
Set<OWLNamedIndividual> e;
for (Node<OWLNamedIndividual> n : w) {
for (OWLNamedIndividual i : n.getEntities()) {
System.out.println(i.getIRI().toString());
}
}
// After you are done with the query, you should remove the
// definition
manager.removeAxiom(ontology, definition);
reasoner.dispose();
} catch (OWLOntologyCreationException | OWLOntologyStorageException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
2
该查询查找位置为“ 1”的人员。 System.out.println应该显示单个的“ Mary”,但没有结果。有人可以告诉我我想念什么吗?
我认为我已经按照http://code.google.com/p/elk-reasoner/wiki/QueryingComplexClasses进行了所有操作。该代码几乎是1:1。
干杯,
S.
最佳答案
您是在手动而不是通过工厂创建推理机。这可能会使它无法监听本体的更新,因此对reasoner.flush()
的调用可能无法正常工作。
尝试使用Reasoner.ReasonerFactory
创建实例,看看是否可以解决您的问题。
另一种可能性是您代码中的IRI与本体中的IRI不匹配。通过打印出您的IRI和ontology.getSignature()
中的IRI,确保它们可以执行此操作。
编辑:确认第二种可能性。我在测试中复制了您的本体片段和您的代码。本体中的IRI类为:
<http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17#Person>
<http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17#PersonWithPosition1>
您代码中的Person类具有IRI:
<#Person>
不匹配是由前缀管理器将
"#"
作为默认名称空间引起的。那不是您的本体的默认名称空间。