A system and method for providing a filtering classloader within a Java-based or other application environment. In one embodiment, a filtering classloader is placed between two other classloaders, e.g. between the system classloader and the application classloader. The filtering classloader is provided with a set of patterns which throw a “class not found exception” if an application makes a request for that class or package. The exception leads the application classloader to believe (perhaps correctly) that there is no class with that name in the system classloader. The application classloader then loads the class itself. The class may or may not exist in the system classloader; the filtering classloader in essence overrides any retrieval from that classloader in favor of the application classloader, for certain specified patterns of request.