public static Resource getSubject(Model r, Resource predicate, RDFNode object)
throws ModelException {
Model m = r.find(null, predicate, object);
if (m == null || m.size() == 0) return null;
// if(m.size() > 1)
// throw new RuntimeException("Model contains more than one triple");
return ((Statement) m.elements().nextElement()).subject();
}
public static RDFNode getObject(Model r, Resource subject, Resource predicate)
throws ModelException {
Model m = r.find(subject, predicate, null);
if (m == null || m.size() == 0) return null;
// if(m.size() > 1)
// throw new RuntimeException("Model contains more than one triple");
// FIXME: we do not check whether it is a resource or literal
return ((Statement) m.elements().nextElement()).object();
}
// FIXME: use digest instead of size
static void getReachable(Resource r, Model m, Model result) throws ModelException {
int oldSize = result.size();
Model directlyReachable = m.find(r, null, null);
SetOperations.unite(result, directlyReachable);
if (result.size() == oldSize) return;
for (Enumeration en = directlyReachable.elements(); en.hasMoreElements(); ) {
Statement t = (Statement) en.nextElement();
if (t.object() instanceof Resource) getReachable((Resource) t.object(), m, result);
}
}
/** returns true if old triples from r were removed */
public static boolean setUniqueObject(
Model r, Resource subject, Resource predicate, RDFNode object) throws ModelException {
Model old = r.find(subject, predicate, null);
SetOperations.subtract(r, old);
Statement stmt = get1(old);
if (subject == null && stmt != null) subject = stmt.subject();
if (predicate == null && stmt != null) predicate = stmt.predicate();
r.add(r.getNodeFactory().createStatement(subject, predicate, object));
return !old.isEmpty();
}
public static List getObjects(Model m, Resource subject, Resource predicate)
throws ModelException {
List result = new ArrayList();
if (m == null || m.size() == 0) return result;
for (Enumeration en = m.find(subject, predicate, null).elements(); en.hasMoreElements(); ) {
Statement st = (Statement) en.nextElement();
result.add(st.object());
}
return result;
}
public static boolean isInstanceOf(Model r, Resource i, Resource cls) throws ModelException {
return !r.find(i, RDF.type, cls).isEmpty();
}