private Node walkTree(
Model model,
Dataset oldDataset,
Node node,
Node predicate,
Query query,
QuerySolution initialBinding,
Set<Node> reached) {
QuerySolutionMap localBinding = new QuerySolutionMap();
localBinding.addAll(initialBinding);
localBinding.add("arg1", model.asRDFNode(node));
Dataset dataset = new DatasetWithDifferentDefaultModel(model, oldDataset);
QueryExecution qexec = ARQFactory.get().createQueryExecution(query, dataset, localBinding);
ResultSet rs = qexec.execSelect();
try {
if (rs.hasNext()) {
List<String> resultVars = rs.getResultVars();
String varName = resultVars.get(0);
RDFNode resultNode = rs.next().get(varName);
if (resultNode != null) {
return resultNode.asNode();
}
}
} finally {
qexec.close();
}
// Recurse into parents
ExtendedIterator<Triple> it = createIterator(model.getGraph(), node, predicate);
try {
while (it.hasNext()) {
Node next = getNext(it.next());
if ((next.isBlank() || next.isURI()) && !reached.contains(next)) {
reached.add(next);
Node nextResult =
walkTree(model, oldDataset, next, predicate, query, initialBinding, reached);
if (nextResult != null) {
return nextResult;
}
}
}
} finally {
it.close();
}
return null;
}
