CODEWITHSUNDEEP
javardfjena
hudi
hudi

Reputation: 16525

How to convert RDF to string

I create some RDF file wih JENA library: Model model = ModelFactory.createDefaultModel();... now how I can I convert this to string ?

thx

Upvotes: 4

Views: 4321

Answers (2)

cygri
cygri

Reputation: 9472

Try something like this:

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

This uses Jena's built-in writers that can already output RDF graphs in the various supported RDF syntaxes, such as RDF/XML and Turtle and N-Triples. If you just want to dump to System.out, then it's even easier:

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

Upvotes: 14

bchetty
bchetty

Reputation: 2241

A RDF model is a set of Statements. Every time you add a property to the model, a Statement is created...and a Statement in RDF model is also called as a 'Triple', coz it has 3 parts: Subject (Resource), Predicate (Property) and Object (RDFNode - can be a Resource). You can call the toString method on these objects, as shown in the code below:

// 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(" .");
}

Note the 'toString' method in the above code.

Source/Ref: Jena - RDF (Check the 'Statements' section).

Upvotes: 0

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