public void testDoesNotReify(String title, Resource r) {
try {
r.as(ReifiedStatement.class);
fail(title + " (" + r + ")");
} catch (DoesNotReifyException e) {
/* that's what we expect */
}
}
/**
* Answer the lowest common ancestor of two classes in a given ontology. This is the class that is
* farthest from the root concept (defaulting to <code>owl:Thing</code> which is a super-class of
* both <code>u</code> and <code>v</code>. The algorithm is based on <a
* href="http://en.wikipedia.org/wiki/Tarjan's_off-line_least_common_ancestors_algorithm">Tarjan's
* off-line LCA</a>. The current implementation expects that the given model:
*
* <ul>
* <li>is transitively closed over the <code>subClassOf</code> relation
* <li>can cheaply determine <em>direct sub-class</em> relations
* </ul>
*
* <p>Both of these conditions are true of the built-in Jena OWL reasoners, such as {@link
* OntModelSpec#OWL_MEM_MICRO_RULE_INF}, and external DL reasoners such as Pellet.
*
* @param m The ontology model being queried to find the LCA, which should conform to the reasoner
* capabilities described above
* @param u An ontology class
* @param v An ontology class
* @return The LCA of <code>u</code> and <code>v</code>
* @exception JenaException if the language profile of the given model does not define a top
* concept (e.g. <code>owl:Thing</code>)
*/
public static OntClass getLCA(OntModel m, OntClass u, OntClass v) {
Resource root = m.getProfile().THING();
if (root == null) {
throw new JenaException(
"The given OntModel has a language profile that does not define a generic root class (such as owl:Thing)");
}
root = root.inModel(m);
return getLCA(m, root.as(OntClass.class), u, v);
}
/**
* the simplest case: if we assert all the components of a reification quad, we can get a
* ReifiedStatement that represents the reified statement.
*/
public void testBasicReification() {
if (model.getReificationStyle() != ModelFactory.Minimal) {
Resource R = model.createResource(aURI);
model.add(R, RDF.type, RDF.Statement);
model.add(R, RDF.subject, S);
model.add(R, RDF.predicate, P);
model.add(R, RDF.object, O);
RDFNode rs = R.as(ReifiedStatement.class);
assertEquals("can recover statement", SPO, ((ReifiedStatement) rs).getStatement());
}
}
/**
* check that, from a model with any combination of the statements given, we can convert R into a
* ReifiedStatement iff the four components of the quad are in the model.
*/
public void testReificationCombinations() {
Resource RR = model.createResource(aURI), SS = model.createResource(anotherURI);
Property PP = (Property) RR.as(Property.class);
Object[][] statements = {
{model.createStatement(RR, RDF.type, RDF.Statement), new Integer(1)},
{model.createStatement(RR, RDF.subject, SS), new Integer(2)},
{model.createStatement(RR, RDF.predicate, PP), new Integer(4)},
{model.createStatement(RR, RDF.object, O), new Integer(8)},
{model.createStatement(SS, PP, O), new Integer(16)},
{model.createStatement(RR, PP, O), new Integer(32)},
{model.createStatement(SS, RDF.subject, SS), new Integer(64)},
{model.createStatement(SS, RDF.predicate, PP), new Integer(128)},
{model.createStatement(SS, RDF.object, O), new Integer(256)},
{model.createStatement(SS, RDF.type, RDF.Statement), new Integer(512)}
};
if (model.getReificationStyle() != ModelFactory.Minimal)
testCombinations(model, RR, 0, statements, statements.length);
}
/**
* walk down the set of statements (represented as an array), recursing with and without each
* statement being present. The mask bits record those statements that are in the model. At the
* bottom of the recursion (n == 0), check that R can be reified exactly when all four quad
* components are present; the other statements don't matter.
*/
private void testCombinations(Model m, Resource R, int mask, Object[][] statements, int n) {
if (n == 0) {
try {
// System.err.println( "| hello. mask = " + mask );
ReifiedStatement rs = (ReifiedStatement) R.as(ReifiedStatement.class);
// System.err.println( "+ we constructed " + rs );
assertTrue(
"should not reify: not all components present [" + mask + "]: " + rs,
(mask & 15) == 15);
// System.err.println( "+ and we passed the assertion." );
} catch (DoesNotReifyException e) { // System.err.println( "+ we exploded" );
assertFalse("should reify: all components present", mask == 15);
}
} else {
int i = n - 1;
Statement s = (Statement) statements[i][0];
int bits = ((Integer) statements[i][1]).intValue();
testCombinations(m, R, mask, statements, i);
m.add(s);
testCombinations(m, R, mask + bits, statements, i);
m.remove(s);
}
}
private static List<RDFNode> asJavaList(Resource resource) {
return (resource.as(RDFList.class)).asJavaList();
}