如何将RDF转换为字符串

时间:2012-04-11 21:17:09

标签: java rdf jena

我使用JENA库创建了一些RDF文件:Model model = ModelFactory.createDefaultModel(); ... 现在我怎么能把它转换成字符串?

THX

2 个答案:

答案 0 :(得分:13)

尝试这样的事情:

String syntax = "RDF/XML-ABBREV"; // also try "N-TRIPLE" and "TURTLE"
StringWriter out = new StringWriter();
model.write(out, syntax);
String result = out.toString();

这使用Jena的内置编写器,这些编写器已经可以在各种支持的RDF语法中输出RDF图,例如RDF / XML和Turtle和N-Triples。如果你只想转储到System.out,那就更容易了:

model.write(System.out, "RDF/XML-ABBREV");

答案 1 :(得分:0)

RDF模型是一组语句。每次向模型添加属性时,都会创建一个Statement ...并且RDF模型中的Statement也称为“ Triple ”,因为它有3个部分:Subject(Resource),谓词(属性)和对象(RDFNode - 可以是资源)。您可以在这些对象上调用toString方法,如下面的代码所示:

// list the statements in the Model
StmtIterator iter = model.listStatements();

// print out the predicate, subject and object of each statement
while (iter.hasNext()) {
    Statement stmt      = iter.nextStatement();  // get next statement
    Resource  subject   = stmt.getSubject();     // get the subject
    Property  predicate = stmt.getPredicate();   // get the predicate
    RDFNode   object    = stmt.getObject();      // get the object

    System.out.print(subject.toString());
    System.out.print(" " + predicate.toString() + " ");
    if (object instanceof Resource) {
       System.out.print(object.toString());
    } else {
        // object is a literal
        System.out.print(" \"" + object.toString() + "\"");
    }

    System.out.println(" .");
} 

请注意上面代码中的'toString'方法。

来源/参考:Jena - RDF(查看“声明”部分)。