Java RDF+；XML响应-缺少XML版本标记

我在Java中有一个sevlet，它创建了一个RDF/XML-ABBREV模型。我的问题是响应不包含xml版本标记

目前的答复：

<rdf:RDF
    xmlns:myNS="http://www.sap.de/research/BusinessObjectOntology#"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:owl="http://www.w3.org/2002/07/owl#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
  <myNS:Resource rdf:about="http://localhost/myResource">
    ...
  </myNS:Resource>
</rdf:RDF>

---

谢谢

声明是可选的，但您可以要求它

根据：

默认行为仅在要求写入使用UTF-8或UTF-16以外编码的OutputStreamWriter时提供XML声明

要自定义输出，请尝试：

...
RDFWriter writer = model.getWriter("RDF/XML-ABBREV");
writer.setProperty("showXmlDeclaration","true");
writer.write(model, resp.getWriter(), null);

...
RDFWriter writer = model.getWriter("RDF/XML-ABBREV");
writer.setProperty("showXmlDeclaration","true");
writer.write(model, resp.getWriter(), null);