RDF/XML本体：在Java中转换为JSON（-LD）树

Question

<?xml version="1.0"?>
<rdf:RDF xmlns="urn:absolute:example.com/"
     xml:base="urn:absolute:example.com/"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:owl="http://www.w3.org/2002/07/owl#"
     xmlns:xml="http://www.w3.org/XML/1998/namespace"
     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
    <owl:Ontology rdf:about="urn:absolute:example.com/"/>



    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Classes
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->




    <!-- urn:absolute:example.com/#CPU -->

    <owl:Class rdf:about="urn:absolute:example.com/#CPU">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Hardware"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Enduser_Application -->

    <owl:Class rdf:about="urn:absolute:example.com/#Enduser_Application">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Software"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#GPU -->

    <owl:Class rdf:about="urn:absolute:example.com/#GPU">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Hardware"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#HDD -->

    <owl:Class rdf:about="urn:absolute:example.com/#HDD">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Storage"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Hardware -->

    <owl:Class rdf:about="urn:absolute:example.com/#Hardware"/>



    <!-- urn:absolute:example.com/#Keyboard -->

    <owl:Class rdf:about="urn:absolute:example.com/#Keyboard">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Peripherals"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Mainboard -->

    <owl:Class rdf:about="urn:absolute:example.com/#Mainboard">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Hardware"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Monitor -->

    <owl:Class rdf:about="urn:absolute:example.com/#Monitor">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Peripherals"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Mouse -->

    <owl:Class rdf:about="urn:absolute:example.com/#Mouse">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Peripherals"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Operating_System -->

    <owl:Class rdf:about="urn:absolute:example.com/#Operating_System">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Software"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Peripherals -->

    <owl:Class rdf:about="urn:absolute:example.com/#Peripherals">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Hardware"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Printer -->

    <owl:Class rdf:about="urn:absolute:example.com/#Printer">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Peripherals"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#SSD -->

    <owl:Class rdf:about="urn:absolute:example.com/#SSD">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Storage"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Software -->

    <owl:Class rdf:about="urn:absolute:example.com/#Software"/>



    <!-- urn:absolute:example.com/#Storage -->

    <owl:Class rdf:about="urn:absolute:example.com/#Storage">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Hardware"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Video_Game -->

    <owl:Class rdf:about="urn:absolute:example.com/#Video_Game">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Enduser_Application"/>
    </owl:Class>



    <!-- urn:absolute:example.com/#Word_Processor -->

    <owl:Class rdf:about="urn:absolute:example.com/#Word_Processor">
        <rdfs:subClassOf rdf:resource="urn:absolute:example.com/#Enduser_Application"/>
    </owl:Class>
</rdf:RDF>



<!-- Generated by the OWL API (version 4.2.8.20170104-2310) https://github.com/owlcs/owlapi -->

Thing
|-- Hardware
  |-- CPU
  |-- GPU
  |-- Mainboard
  |-- Peripherals
    |-- Keyboard
    |-- Monitor
    |-- Mouse
    |-- Printer
  |-- Storage
    |-- HDD
    |-- SSD
|-- Software
  |-- Enduser_Application
    |-- Video_Game
    |-- Word_Processor
  |-- Operating_System

我已经试过几种不同的方法了。

>

使用Apache Jena

Model model = ModelFactory.createOntologyModel();
model.read(ontology, "OWL");
model.write(new BufferedWriter(f), "JSON-LD");

这似乎是目前“最好的”工作。我最终得到一个包含JSON-LD数据的字符串，它是一个树状表示。但是类关系是颠倒的：

我注意到JSON-LD有一个所谓的“框架”特性，它基本上允许您将数据重新放入定义的框架中。

我将JSON-LD的@reverse关键字与rdfs:subclassof结合起来进行了修改，希望从本质上颠倒关系。但是，我也不能让它起作用，而且我对JSON-LD也不是很有经验。因此，我有些挣扎。

这已经导致了我的一些不眠之夜。如果有人知道这个问题的解决方法，或者只是能给我如何解决这个问题的提示，我会很高兴的。

Answer 1

我检查了一下，我确实能够使用OWL API加载您的本体并将其保存为JsonLD格式。不过，我怀疑它能解决你的问题，就像@Ignazio指出的那样。为了打印出树结构，您需要访问一个推理器，从中可以查询包含关系。

这里有一个代码样例，装载和保存你的本体，并将它打印在树状结构中。

private static Logger logger = LoggerFactory
        .getLogger(owl.api.test.StandaloneOWLNamedIndividualRetrievalv5.AppHardwareTest.class);
// Why This Failure marker
private static final Marker WTF_MARKER = MarkerFactory.getMarker("WTF");

static OWLReasoner reasoner;

static void printChildren(NodeSet<OWLClass> owlClasses) {
    for (Node<OWLClass> node : owlClasses) {
        logger.trace(node.getRepresentativeElement().toString());
        if (!node.getRepresentativeElement().isBottomEntity())
            printChildren(reasoner.getSubClasses(node.getRepresentativeElement()));
    }       
}

public static void main(String[] args) {
    try {
        // Setup physical IRI for storing ontology
        Path path = Paths.get(".").toAbsolutePath().normalize();
        IRI loadDocumentIRI = IRI.create("file:" + path.toFile().getAbsolutePath() + "/hardware.owl");
        IRI saveDocumentIRI = IRI.create("file:" + path.toFile().getAbsolutePath() + "/hardwareSave.txt");

        // Initialize
        OWLOntologyManager manager = OWLManager.createOWLOntologyManager();
        OWLOntology ontology = manager.loadOntologyFromOntologyDocument(loadDocumentIRI);

        // Write to JsonLD format
        OWLDocumentFormat ontologyFormat = new RDFJsonLDDocumentFormat();
        manager.saveOntology(ontology, ontologyFormat, saveDocumentIRI);        

        // Print tree structure
        OWLReasonerFactory reasonerFactory = new JFactFactory();
        reasoner = reasonerFactory.createReasoner(ontology);            
        Node<OWLClass> top = reasoner.getTopClassNode();
        logger.trace(top.getRepresentativeElement().toString());
        printChildren(reasoner.getSubClasses(top.getRepresentativeElement()));          
    } catch (Throwable t) {
        logger.error(WTF_MARKER, t.getMessage(), t);
    }
}

希望有帮助。祝你好运.