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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，无论我对推理器有什么查询，都没有输出，它不提供任何实例。

这就是我的本体的样子：

    <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 查询查找位置为“1”的人。System.out.println 应该显示单个“Mary”，但没有结果。有人可以告诉我我错过了什么吗？我想我按照http://code.google.com/p/elk-reasoner/wiki/QueryingComplexClasses做了所有事情。代码几乎是 1:1。

干杯，S。

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1 回答 1

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您正在手动创建推理器，而不是通过其工厂。这可能会导致它无法侦听本体的更新，因此调用reasoner.flush()可能无法正常工作。尝试使用Reasoner.ReasonerFactory来创建实例，看看这是否能解决您的问题。

另一种可能性是代码中的 IRI 与本体中的 IRI 不匹配。通过打印出您的 IRI 和ontology.getSignature().

编辑：第二种可能性得到确认。我在测试中复制了您的本体片段和代码。您的本体中的 IRI 类是：

<http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17#Person>
<http://www.semanticweb.org/sabse/ontologies/2013/11/untitled-ontology-17#PersonWithPosition1>

代码中的 Person 类具有 IRI：

<#Person>

不匹配是由具有"#"默认命名空间的前缀管理器引起的。这不是您的本体的默认命名空间。

于 2013-12-15T22:36:09.673 回答