ishmaelMakitla ishmaelMakitla - 26 days ago 8
Java Question

Inserting an OntModel instance into a Triple Store (like TDB) using ARQ (SPARQL processor for Jena)

How can I insert an OntModel instance into a Triple Store (like TDB) using ARQ (SPARQL processor for Jena? I have the following code which simply creates books, and add these into an OntModel. Now I want to insert this into a Triple Store:

public static void createDummyBooks(){
// Create an empty ontology model
OntModel ontModel = ModelFactory.createOntologyModel();
String ns = new String("http://www.iexample.com/book#");
String baseURI = new String("http://www.iexample.com/book");
Ontology onto = ontModel.createOntology(baseURI);

//creating a book
OntClass book = ontModel.createClass(ns + "Book");
OntClass nonFinctionBook = ontModel.createClass(ns + "NonFictionBook");
OntClass fictionBook = ontModel.createClass(ns + "FictionBook");

// Create datatype property 'hasAge'
DatatypeProperty hasTtitle = ontModel.createDatatypeProperty(ns + "hasTitle");
// 'hasAge' takes integer values, so its range is 'integer'
// Basic datatypes are defined in the ‘vocabulary’ package
hasTtitle.setDomain(book);
hasTtitle.setRange(XSD.xstring); // com.hp.hpl.jena.vocabulary.XSD

// Create individuals
Individual theProgrammingBook = nonFinctionBook.createIndividual(ns + "ProgrammingBook");
Individual theFantasyBook = fictionBook.createIndividual(ns + "FantasyBook");


Literal bookTitle = ontModel.createTypedLiteral("Programming with Ishmael", XSDDatatype.XSDstring);
Literal fantasyBookTitle = ontModel.createTypedLiteral("The adventures of Ishmael", XSDDatatype.XSDstring);
// Create statement 'ProgrammingBook hasTitle "Programming with Ishmael" '
Statement theProgrammingBookHasTitle = ontModel.createStatement(nonFinctionBook, hasTtitle, bookTitle);
// Create statement 'FantasyBook hasTitle "The adventures of Ishmael" '
Statement theFantasyBookHasTitle = ontModel.createStatement(theFantasyBook, hasTtitle, fantasyBookTitle);
List<Statement> statements = new ArrayList<Statement>();
statements.add(theProgrammingBookHasTitle);
statements.add(theFantasyBookHasTitle);

ontModel.add(statements);
//just displaying here - but how do I now write/insert this into my Triple Store/TDB using AQR API?
ontModel.write(System.out, "RDF/XML-ABBREV");

}


Any ideas? Much appreciated.

Answer Source

After some searching and playing around with the API. I came across this very useful tutorial - although it had a specific focus, it did give me some good idea about what I needed to do. So this is how I eventually managed to insert/add my OntModel into my existing dataset on Fuseki Server using HTTP Dataset Accessor DatasetAccessor.

//The Graph Store protocol for sem_tutorials (my dummy dataset) is http://localhost:3030/sem_tutorials/data
private static final String FUSEKI_SERVICE_DATASETS_URI = "http://localhost:3030/sem_tutorials/data";
private void testSavingModel(OntModel model){
  DatasetAccessor accessor = DatasetAccessorFactory.createHTTP(FUSEKI_SERVICE_DATASETS_URI);
 if(accessor != null){
    //because I already had a number of Triples there already - I am only adding this model
    accessor.add(model);
  }
}

It was that easy! So when I checked by running SPARQL query select * {?s ?p ?o} - the data was there! I hope this will also be useful to those who are working on Semantic Web applications using Jena.