java - 如何将 RDF 三元组添加到 OWLOntology？

Question

我有一些数据来自 RabbitMQ。数据被格式化为三元组，因此来自队列的消息可能如下所示:

:Tom foaf:knows :Anna

其中 : 是我要将数据导入其中的本体的标准命名空间，但导入的其他前缀也是可能的。三元组由主语、属性/谓语和宾语组成，我在每条消息中都知道哪个是哪个。

在接收方，我有一个带有 OWLOntology 的 Java 程序表示本体的对象，新到达的三元组应临时存储在其中以用于推理和其他内容。我设法把三元组变成了耶拿 OntModel但这就是它结束的地方。我尝试使用 OWLRDFConsumer但我找不到任何关于如何应用它的信息。

我的函数看起来像这样:

public void addTriple(RDFTriple triple) {

    //OntModel model = ModelFactory.createOntologyModel();

    String subject = triple.getSubject().toString();
    subject = subject.substring(1,subject.length()-1);
    Resource s = ResourceFactory.createResource(subject);

    String predicate = triple.getPredicate().toString();
    predicate = predicate.substring(1,predicate.length()-1);
    Property p = ResourceFactory.createProperty(predicate);

    String object = triple.getObject().toString();
    object = object.substring(1,object.length()-1);
    RDFNode o = ResourceFactory.createResource(object);

    Statement statement = ResourceFactory.createStatement(s, p, o);
    //model.add(statement);

    System.out.println(statement.toString());
}

我执行了子字符串操作，因为 RDFTriple 类在三元组的参数周围添加了 <>，结果 Statement 的构造函数失败了。

如果有人能给我指出一个很好的例子。也许有一种我没有想到的更好的方法来实现同样的目标？

Answer 1

OWLRDFConsumer 似乎通常用于连接 RDF 解析器和 OWL 感知处理器。以下代码似乎有效，但是，正如我在评论中指出的那样，有几个地方我需要一个参数并放入我唯一可以使用的东西。

以下代码:创建本体；宣布两个有名字的人，汤姆和安娜；声明一个对象属性，喜欢；并声明一个数据属性，年龄。一旦声明了这些，我们就打印本体只是为了确保它是我们所期望的。然后它创建一个 OWLRDFConsumer。消费者构造函数需要一个本体，一个 AnonymousNodeChecker , 和一个 OWLOntologyLoaderConfiguration .对于配置，我只使用了一个由无参数构造函数创建的配置，我认为这没问题。对于节点检查器，唯一方便的实现器是 TurtleParser，因此我创建了其中一个，将 null 作为 Reader 传递。我认为这没问题，因为不会调用解析器来读取任何内容。那么消费者的handle(IRI,IRI,IRI)和 handle(IRI,IRI,OWLLiteral)方法用于一次处理一个三元组。我们添加三元组

:Tom :likes :Anna
:Tom :age 35

然后再次打印出本体以确保添加了断言。由于您已经获得 RDFTriples，因此您应该能够提取 handle() 所需的参数。在处理三元组之前，本体包含:

<NamedIndividual rdf:about="http://example.org/Tom"/>

然后是:

<NamedIndividual rdf:about="http://example.org/Tom">
  <example:age rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">35</example:age>
  <example:likes rdf:resource="http://example.org/Anna"/>
</NamedIndividual>

代码如下:

import java.io.Reader;

import org.coode.owlapi.rdfxml.parser.OWLRDFConsumer;
import org.semanticweb.owlapi.apibinding.OWLManager;
import org.semanticweb.owlapi.model.IRI;
import org.semanticweb.owlapi.model.OWLDataFactory;
import org.semanticweb.owlapi.model.OWLDataProperty;
import org.semanticweb.owlapi.model.OWLEntity;
import org.semanticweb.owlapi.model.OWLNamedIndividual;
import org.semanticweb.owlapi.model.OWLObjectProperty;
import org.semanticweb.owlapi.model.OWLOntology;
import org.semanticweb.owlapi.model.OWLOntologyCreationException;
import org.semanticweb.owlapi.model.OWLOntologyLoaderConfiguration;
import org.semanticweb.owlapi.model.OWLOntologyManager;
import org.semanticweb.owlapi.model.OWLOntologyStorageException;

import uk.ac.manchester.cs.owl.owlapi.turtle.parser.TurtleParser;


public class ExampleOWLRDFConsumer {
    public static void main(String[] args) throws OWLOntologyCreationException, OWLOntologyStorageException {
        // Create an ontology.
        OWLOntologyManager manager = OWLManager.createOWLOntologyManager();
        OWLDataFactory factory = manager.getOWLDataFactory();
        OWLOntology ontology = manager.createOntology();

        // Create some named individuals and an object property.
        String ns = "http://example.org/";
        OWLNamedIndividual tom = factory.getOWLNamedIndividual( IRI.create( ns+"Tom" ));
        OWLObjectProperty likes = factory.getOWLObjectProperty( IRI.create( ns+"likes" ));
        OWLDataProperty age = factory.getOWLDataProperty( IRI.create( ns+"age" ));
        OWLNamedIndividual anna = factory.getOWLNamedIndividual( IRI.create( ns+"Anna" ));

        // Add the declarations axioms to the ontology so that the triples involving
        // these are understood (otherwise the triples will be ignored).
        for ( OWLEntity entity : new OWLEntity[] { tom, likes, age, anna } ) {
            manager.addAxiom( ontology, factory.getOWLDeclarationAxiom( entity ));
        }

        // Print the the ontology to see that the entities are declared. 
        // The important result is
        //  <NamedIndividual rdf:about="http://example.org/Tom"/>
        // with no properties
        manager.saveOntology( ontology, System.out );

        // Create an OWLRDFConsumer for the ontology.  TurtleParser implements AnonymousNodeChecker, so 
        // it was a candidate for use here (but I make no guarantees about whether it's appropriate to 
        // do this).  Since it won't be reading anything, we pass it a null InputStream, and this doesn't
        // *seem* to cause any problem.  Hopefully the default OWLOntologyLoaderConfiguration is OK, too.
        OWLRDFConsumer consumer = new OWLRDFConsumer( ontology, new TurtleParser((Reader) null), new OWLOntologyLoaderConfiguration() );

        // The consumer handles (IRI,IRI,IRI) and (IRI,IRI,OWLLiteral) triples.
        consumer.handle( tom.getIRI(), likes.getIRI(), anna.getIRI() );
        consumer.handle( tom.getIRI(), age.getIRI(), factory.getOWLLiteral( 35 ));

        // Print the ontology to see the new object and data property assertions.  The import contents is
        // still Tom: 
        //   <NamedIndividual rdf:about="http://example.org/Tom">
        //     <example:age rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">35</example:age>
        //     <example:likes rdf:resource="http://example.org/Anna"/>
        //  </NamedIndividual>
        manager.saveOntology( ontology, System.out );
    }
}