如何使用耶拿将诸如floatintdate的数值添加到Resource中?

我假设我必须使用resource.addProperty(Property, String, RDFDataType),但是如何为上述数据类型实例化正确的RDFDataType呢?

最佳答案

有关键入文字的“官方”文档在这里:
http://incubator.apache.org/jena/documentation/notes/typed-literals.html

您可以使用Jena 模型 addLiteral add 方法,例如:

    Model model = ...

    model.addLiteral (subject, predicate, 10);
    model.addLiteral (subject, predicate, 0.5);
    model.addLiteral (subject, predicate, (float)0.5);
    model.addLiteral (subject, predicate, ResourceFactory.createTypedLiteral(20));
    model.addLiteral (subject, predicate, ResourceFactory.createTypedLiteral(0.99));
    model.addLiteral (subject, predicate, true);
    model.add (subject, predicate, ResourceFactory.createTypedLiteral("2012-03-11", XSDDatatype.XSDdate));
    model.add (subject, predicate, ResourceFactory.createTypedLiteral("P2Y", XSDDatatype.XSDduration));

RDFDatatype 是一个接口,因此无法直接实例化它。但是,请看实现该接口的类。您会发现XSDDatatype是这些类之一。还有其他

如果要查看完整示例,请在此处查看:
https://github.com/castagna/jena-examples/blob/master/src/main/java/org/apache/jena/examples/ExampleDataTypes_01.java。 ExampleDataTypes_01.java的输出是以下RDF(使用Turtle格式序列化):
@prefix xsd:     <http://www.w3.org/2001/XMLSchema#> .
@prefix example:  <http://example.org/> .

example:s
      example:p1 "10"^^xsd:int ;
      example:p2 "0.5"^^xsd:double ;
      example:p3 "0.5"^^xsd:float ;
      example:p4 "20"^^xsd:int ;
      example:p5 "0.99"^^xsd:double ;
      example:p6 "true"^^xsd:boolean ;
      example:p7 "2012-03-11"^^xsd:date ;
      example:p8 "P2Y"^^xsd:duration .

10-07 19:13
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