Replacing blank node IDs

[simon]

I've Triples extracted from the web like:

_:na43d612388514fcfaaa74771e40a879cxb0
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/Product> .
_:na43d612388514fcfaaa74771e40a879cxb0 <http://schema.org/brand>
_:na43d612388514fcfaaa74771e40a879cxb2 .
_:na43d612388514fcfaaa74771e40a879cxb0 <http://schema.org/mpn> "925872" .
_:na43d612388514fcfaaa74771e40a879cxb0 <http://schema.org/name>
"Executive Anvil" .
...

but would like to replace the blank node IDs with non-blank IDs that
reflect the URI where the data came from. I've loaded the data in a
RDF4J Model successfully but don't know if what I want to do is
possible or how to proceed from there.

Thanking you in advance for your help and suggestions, Simon.

[Jeen Broekstra]

Off the top of my head a simple way to do this for a Model is something like this:

Model model = ... // your model with blank nodes

Model converted = model.stream.map(st -> convert(st)).collect(ModelCollector.toModel());

Statement convert(Statement st) {

        var subject = st.getSubject();

        var object = st.getObject();

        if (!(subject.isBNode() || object.isBNode())) {            

            return st;

        }

        IRI newSubject = subject.isBNode() ? Values.iri("http://example.org/", subject.stringValue()) : (IRI) subject;

        Value newObject = object.isBNode() ? Values.iri("http://example.org/", object.stringValue()) : object;

        return Values.statement(newSubject, st.getPredicate(), newObject, st.getContext());

}

Of course, what's also possible is to do the conversion while parsing (so before you even have created a Model object for it), something like this:

       

        RDFParser parser = Rio.createParser(RDFFormat.TURTLE);

        parser.getParserConfig().set(BasicParserSettings.SKOLEMIZE_ORIGIN, "http://example.org/");

        Model model = new TreeModel();

        parser.setRDFHandler(new StatementCollector(model));

        parser.parse(input);

        model.forEach(System.out::println); // will print out the model to show all bnodes converted to IRIs

Cheers,

Jeen

[simon t]

I wanted more control of the IDs than SKOLEMIZE_ORIGIN provided so went something closer to the convert() approach, streaming and map-ing worked great.

Thanks for saving me some time figuring this out, Simon