private static List<Resource> equivalentTypes(Resource type) {
List<Resource> types = new ArrayList<Resource>();
types.add(type);
for (StmtIterator it = type.getModel().listStatements(ANY, OWL.equivalentClass, type);
it.hasNext(); ) types.add(it.nextStatement().getSubject());
return types;
}
/**
* Answer the shortest path from the <code>start</code> resource to the <code>end</code> RDF node,
* such that every step on the path is accepted by the given filter. A path is a {@link List} of
* RDF {@link Statement}s. The subject of the first statement in the list is <code>start</code>,
* and the object of the last statement in the list is <code>end</code>.
*
* <p>The <code>onPath</code> argument is a {@link Filter}, which accepts a statement and returns
* true if the statement should be considered to be on the path. To search for an unconstrained
* path, pass {@link Filter#any} as an argument. To search for a path whose predicates match a
* fixed restricted set of property names, pass an instance of {@link PredicatesFilter}.
*
* <p>If there is more than one path of minimal length from <code>start</code> to <code>end</code>
* , this method returns an arbitrary one. The algorithm is blind breadth-first search, with loop
* detection.
*
* @param m The model in which we are seeking a path
* @param start The starting resource
* @param end The end, or goal, node
* @param onPath A filter which determines whether a given statement can be considered part of the
* path
* @return A path, consisting of a list of statements whose first subject is <code>start</code>,
* and whose last object is <code>end</code>, or null if no such path exists.
*/
public static Path findShortestPath(
Model m, Resource start, RDFNode end, Filter<Statement> onPath) {
List<Path> bfs = new LinkedList<Path>();
Set<Resource> seen = new HashSet<Resource>();
// initialise the paths
for (Iterator<Statement> i = m.listStatements(start, null, (RDFNode) null).filterKeep(onPath);
i.hasNext(); ) {
bfs.add(new Path().append(i.next()));
}
// search
Path solution = null;
while (solution == null && !bfs.isEmpty()) {
Path candidate = bfs.remove(0);
if (candidate.hasTerminus(end)) {
solution = candidate;
} else {
Resource terminus = candidate.getTerminalResource();
if (terminus != null) {
seen.add(terminus);
// breadth-first expansion
for (Iterator<Statement> i = terminus.listProperties().filterKeep(onPath);
i.hasNext(); ) {
Statement link = i.next();
// no looping allowed, so we skip this link if it takes us to a node we've seen
if (!seen.contains(link.getObject())) {
bfs.add(candidate.append(link));
}
}
}
}
}
return solution;
}
public Collection<URI> getSupportedFacets(URI needUri) throws NoSuchNeedException {
List<URI> ret = new LinkedList<URI>();
Need need = DataAccessUtils.loadNeed(needRepository, needUri);
Model content = rdfStorageService.loadContent(need);
if (content == null) return ret;
Resource baseRes = content.getResource(content.getNsPrefixURI(""));
StmtIterator stmtIterator = baseRes.listProperties(WON.HAS_FACET);
while (stmtIterator.hasNext()) {
RDFNode object = stmtIterator.nextStatement().getObject();
if (object.isURIResource()) {
ret.add(URI.create(object.toString()));
}
}
return ret;
}
private static ResultSetRewindable unique(ResultSetRewindable results) {
// VERY crude. Utilises the fact that bindings have value equality.
List<Binding> x = new ArrayList<Binding>();
Set<Binding> seen = new HashSet<Binding>();
for (; results.hasNext(); ) {
Binding b = results.nextBinding();
if (seen.contains(b)) continue;
seen.add(b);
x.add(b);
}
QueryIterator qIter = new QueryIterPlainWrapper(x.iterator());
ResultSet rs =
new ResultSetStream(results.getResultVars(), ModelFactory.createDefaultModel(), qIter);
return ResultSetFactory.makeRewindable(rs);
}
private ResultSetRewindable convertToStrings(ResultSetRewindable resultsActual) {
List<Binding> bindings = new ArrayList<Binding>();
while (resultsActual.hasNext()) {
Binding b = resultsActual.nextBinding();
BindingMap b2 = BindingFactory.create();
for (String vn : resultsActual.getResultVars()) {
Var v = Var.alloc(vn);
Node n = b.get(v);
String s;
if (n == null) s = "";
else if (n.isBlank()) s = "_:" + n.getBlankNodeLabel();
else s = NodeFunctions.str(n);
b2.add(v, NodeFactory.createLiteral(s));
}
bindings.add(b2);
}
ResultSet rs =
new ResultSetStream(
resultsActual.getResultVars(), null, new QueryIterPlainWrapper(bindings.iterator()));
return ResultSetFactory.makeRewindable(rs);
}
