/**
* LDP-Style to serialize a resource.
*
* @param writer the writer to serialize to
* @param subject the resource to serialize
* @param iteration the Iteration containing the data
* @throws RDFHandlerException
* @throws RepositoryException
*/
public static void exportIteration(
RDFWriter writer, URI subject, CloseableIteration<Statement, RepositoryException> iteration)
throws RDFHandlerException, RepositoryException {
writer.startRDF();
writer.handleNamespace(LDP.PREFIX, LDP.NAMESPACE);
writer.handleNamespace(RDF.PREFIX, RDF.NAMESPACE);
writer.handleNamespace(XSD.PREFIX, XSD.NAMESPACE);
writer.handleNamespace(DCTERMS.PREFIX, DCTERMS.NAMESPACE);
writer.handleNamespace("parent", subject.getNamespace());
writer.handleNamespace("child", subject.stringValue().replaceFirst("/*$", "/"));
writer.handleNamespace("this", subject.stringValue().replaceFirst("/*$", "#"));
while (iteration.hasNext()) {
writer.handleStatement(iteration.next());
}
writer.endRDF();
}
public static void writeNanopub(Nanopub nanopub, OutputStream out, RDFFormat format)
throws RDFHandlerException {
RDFWriter writer = Rio.createWriter(format, out);
writer.startRDF();
String s = nanopub.getUri().toString();
writer.handleNamespace("this", s);
writer.handleNamespace("sub", s + ".");
writer.handleNamespace("blank", s + "..");
writer.handleNamespace("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
writer.handleNamespace("rdfs", "http://www.w3.org/2000/01/rdf-schema#");
writer.handleNamespace("rdfg", "http://www.w3.org/2004/03/trix/rdfg-1/");
writer.handleNamespace("xsd", "http://www.w3.org/2001/XMLSchema#");
writer.handleNamespace("owl", "http://www.w3.org/2002/07/owl#");
writer.handleNamespace("dc", "http://purl.org/dc/terms/");
writer.handleNamespace("pav", "http://swan.mindinformatics.org/ontologies/1.2/pav/");
writer.handleNamespace("np", "http://www.nanopub.org/nschema#");
for (Statement st : NanopubUtils.getStatements(nanopub)) {
writer.handleStatement(st);
}
writer.endRDF();
}
public void test_query() throws Exception {
final BigdataSail sail = getSail();
try {
sail.initialize();
if (!((BigdataSail) sail).database.getStatementIdentifiers()) {
log.warn("Statement identifiers are not enabled");
return;
}
/*
* Load data into the sail.
*/
{
final DataLoader dataLoader = sail.database.getDataLoader();
dataLoader.loadData(
"/com/bigdata/rdf/sail/provenance01.ttlx",
"" /*baseURL*/,
ServiceProviderHook.TURTLE_RDR);
}
/*
* Serialize as RDF/XML.
*
* Note: This is just for debugging.
*/
if (log.isInfoEnabled()) {
final BigdataStatementIterator itr = sail.database.getStatements(null, null, null);
final String rdfXml;
try {
final Writer w = new StringWriter();
// final RDFXMLWriter rdfWriter = new RDFXMLWriter(w);
final RDFWriterFactory writerFactory =
RDFWriterRegistry.getInstance().get(RDFFormat.RDFXML);
assertNotNull(writerFactory);
final RDFWriter rdfWriter = writerFactory.getWriter(w);
rdfWriter.startRDF();
while (itr.hasNext()) {
final BigdataStatementImpl stmt = (BigdataStatementImpl) itr.next();
// only write the explicit statements.
if (!stmt.isExplicit()) continue;
rdfWriter.handleStatement(stmt);
}
rdfWriter.endRDF();
rdfXml = w.toString();
} finally {
itr.close();
}
// write the rdf/xml
log.info(rdfXml);
}
final SailConnection conn = sail.getConnection();
try {
final URI y = new URIImpl("http://www.foo.org/y");
final URI B = new URIImpl("http://www.foo.org/B");
final URI dcCreator = new URIImpl("http://purl.org/dc/terms/creator");
final Literal bryan = new LiteralImpl("bryan");
final Literal mike = new LiteralImpl("mike");
/*
* This is a hand-coded query.
*
* Note: When statement identifiers are enabled, the only way to
* bind the context position is to already have a statement on hand -
* there is no index which can be used to look up a statement by its
* context and the context is always a blank node.
*/
// final TupleExpr tupleExpr =
// new Projection(
// new Join(//
// new StatementPattern(//
// new Var("X", y),//
// new Var("1", RDF.TYPE),//
// new Var("2", B),//
// new Var("SID")),// unbound.
// new StatementPattern(//
// new Var("SID"),//
// new Var("3", dcCreator),//
// new Var("Y"))),
// new ProjectionElemList(new ProjectionElem[] { new ProjectionElem( "Y"
// )}));
// final String q = "select ?Y where { ?SID <"+dcCreator+"> ?Y . graph ?SID {
// <"+y+"> <"+RDF.TYPE+"> <"+B+"> . } }";
final String q =
"select ?Y where { <<<"
+ y
+ "> <"
+ RDF.TYPE
+ "> <"
+ B
+ ">>> <"
+ dcCreator
+ "> ?Y . }";
/*
* Create a data set consisting of the contexts to be queried.
*
* Note: a [null] DataSet will cause context to be ignored when the
* query is processed.
*/
// final DatasetImpl dataSet = null; //new DatasetImpl();
//
// final BindingSet bindingSet = new QueryBindingSet();
//
// final CloseableIteration<? extends BindingSet, QueryEvaluationException> itr =
// conn
// .evaluate(tupleExpr, dataSet, bindingSet, true/* includeInferred */);
final TupleQuery tq =
new BigdataSailRepository(sail)
.getReadOnlyConnection()
.prepareTupleQuery(QueryLanguage.SPARQL, q);
final TupleQueryResult itr = tq.evaluate();
if (log.isInfoEnabled()) log.info("Verifying query.");
/*
* These are the expected results for the query (the bindings for Y).
*/
final Set<Value> expected = new HashSet<Value>();
expected.add(bryan);
expected.add(mike);
/*
* Verify that the query results is the correct solutions.
*/
final int nresults = expected.size();
try {
int i = 0;
while (itr.hasNext()) {
final BindingSet solution = itr.next();
if (log.isInfoEnabled()) log.info("solution[" + i + "] : " + solution);
final Value actual = solution.getValue("Y");
assertTrue("Not expecting Y=" + actual, expected.remove(actual));
i++;
}
assertEquals("#results", nresults, i);
} finally {
itr.close();
}
} finally {
conn.close();
}
} finally {
sail.__tearDownUnitTest();
}
}
