/**
* Returns set of all effective interfaces implied by a given interface. This set is constructed
* by traversing the interface inheritance hierarchy from the given interface to the root(s) of
* the hierarchy, collecting all interfaces along the way, including the starting interface.
*
* @param itfClass interface class where the traversal should start
* @return set of all effective interfaces implied by the given interface
*/
public static Set<Class<?>> getEffectiveInterfaces(final Class<?> itfClass) {
//
// Traverse the hierarchy in a breadth-first manner. Add newly visited
// interfaces to the result set and their super interfaces to the queue
// of interfaces to visit.
//
final Set<Class<?>> result = Sets.newHashSet();
final Queue<Class<?>> queue = Lists.newLinkedList();
queue.add(itfClass);
while (!queue.isEmpty()) {
final Class<?> itf = queue.poll();
result.add(itf);
for (final Class<?> superItf : itf.getInterfaces()) {
if (!result.contains(superItf)) {
queue.add(superItf);
}
}
}
return result;
}
