Jersey ExceptionMapper doesn't map exceptions

Answer that solved my problems:

I've put packages("package.name"); which is my root package name and exception mappers work like a charm.

@Component
@ApplicationPath("/api")
public class JerseyConfig extends ResourceConfig
{
public JerseyConfig()
{
    packages("package.name");
    register(UserController.class);
    register(TimezoneController.class);
}
}