A resource (in a jar file, usually) in the format "/java/lang/String.
A resource (in a jar file, usually) in the format "/java/lang/String.class". This returns an initial URL that leads to the JAR file we search for classes.
Returns true if this is a "valid" class, i.
Returns true if this is a "valid" class, i.e. one we want to return in a set. Note that all found classes are loaded into the current thread's classloader, even they are not returned.
true if this class should be returned in the set of findClasses, false otherwise.
Loads a set of classes from a package (including ones which are NOT already in the classloader) and return the set that