java - JENA : Create a single Statement based on a String object -

i have parse n-triple content , apply modification on every literal of given type.

for example, have modify every wktliteral make them using referential. triples such :

"point (0.0 0.0)"^^<http://www.opengis.net/ont/geosparql#wktliteral> 

must become :

"<http://www.opengis.net/def/crs/epsg/0/4326> point (0.0 0.0)"^^<http://www.opengis.net/ont/geosparql#wktliteral> 

i got each triple line line string object , create jena statement string. aim use jena parsers avoid dirty string manipulation such split error prone.

for way find :

string line = "%a triple here%"; //create empty model final model model = modelfactory.createdefaultmodel(); //parse , store rdf triple in model rdfdatamgr.read(model, new bytearrayinputstream(line.getbytes(standardcharsets.utf_8)), lang.ntriples); //get statements - 1 if final stmtiterator liststatements = model.liststatements(); //got statement final statement statement = liststatements.next(); 

i tried use rdfreader don't know use rdfoutputstream... statement object automatically created string have create model,use reader , iterator. seems overkill in opinion (i cutted off of test such testing there next statement...) .

do know kicker/simpler way achieve ?

arthur.

you'll find using streams more efficient. streamrdf instances sent triples encountered. can rewrite appropriate.

streams use spi level of jena -- nodes, triples , quads rather statements, resources, etc -- lack niceities tasks ideal.

given you've written suspect writing out fixed n-triples want? here's example that. 1) create stream output triples, 2) create stream waits triples, corrects object (if needed), , writes results , 3) starts whole parse going:

final string wkt = "http://www.opengis.net/ont/geosparql#wktliteral";  // stream result stdout final streamrdf outputhandler = streamrdflib.writer(system.out);  streamrdf inputhandler = new streamrdfbase() {     @override     public void triple(triple triple) { // got triple         node object = triple.getobject();          node transformed;         // if object literal , has wkt type         if (object.isliteral() &&                 wkt.equals(object.getliteraldatatypeuri())) {             // make new node, suitably modified             transformed = nodefactory.createliteral(                     "<http://www.opengis.net/def/crs/epsg/0/4326> "                              + object.getliterallexicalform(),                      object.getliteraldatatype());         } else { // nothing             transformed = object;         }          // write out corrected object         outputhandler.triple(                 triple.create( triple.getsubject(), triple.getpredicate(),                         transformed                         ));     } };  // parse  rdfdatamgr.parse(inputhandler, rdfdatamgr.open("file"));