File moduleFile = new File(Catalog.class.getProtectionDomain().getCodeSource().getLocation().toURI());
final ClassFinder finder = new ClassFinder();
finder.clear();
assertTrue(finder.add(moduleFile));
final ClassFilter filter = new AndClassFilter(new NotClassFilter(new InterfaceOnlyClassFilter()), new NotClassFilter(new AbstractClassFilter()), new SubclassClassFilter(UpdateTask.class));
Collection<ClassInfo> foundClasses = new ArrayList<ClassInfo>();
finder.findClasses(foundClasses, filter);

Using http://www.clapper.org/software/java/util/javadocs/util/api/org/clapper/util/classutil/ClassFinder.html in order to find a class in class path.

Finding classes

class, java

Java