/**
* Constant-valued term maps can be expressed more concisely using the constant shortcut
* properties rr:subject, rr:predicate, rr:object and rr:graph. Occurrances of these properties
* must be treated exactly as if the following triples were present in the mapping graph instead.
*
* @param r2rmlMappingGraph
*/
private static void replaceShortcuts(SesameDataSet r2rmlMappingGraph) {
Map<URI, URI> shortcutPredicates = new HashMap<URI, URI>();
shortcutPredicates.put(
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.SUBJECT),
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.SUBJECT_MAP));
shortcutPredicates.put(
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.PREDICATE),
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.PREDICATE_MAP));
shortcutPredicates.put(
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.OBJECT),
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.OBJECT_MAP));
shortcutPredicates.put(
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.GRAPH),
vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.GRAPH_MAP));
for (URI u : shortcutPredicates.keySet()) {
List<Statement> shortcutTriples = r2rmlMappingGraph.tuplePattern(null, u, null);
log.debug(
"[RMLMappingFactory:replaceShortcuts] Number of R2RML shortcuts found "
+ "for "
+ u.getLocalName()
+ " : "
+ shortcutTriples.size());
for (Statement shortcutTriple : shortcutTriples) {
r2rmlMappingGraph.remove(
shortcutTriple.getSubject(), shortcutTriple.getPredicate(), shortcutTriple.getObject());
BNode blankMap = vf.createBNode();
URI pMap = vf.createURI(shortcutPredicates.get(u).toString());
URI pConstant = vf.createURI(Vocab.R2RML_NAMESPACE + R2RMLTerm.CONSTANT);
r2rmlMappingGraph.add(shortcutTriple.getSubject(), pMap, blankMap);
r2rmlMappingGraph.add(blankMap, pConstant, shortcutTriple.getObject());
}
}
}
