@Path("a")
class A {}

Class ConfigA extends jersey.server.ResourceConfig...{
    public ConfigA {
      register(A.class)
    }
}

@Path("a") //SAME PATH as A
Class B extends A{}

Class ConfigB extends ConfigA{
      public ConfigB(){
        super();
        //TODO Unregister the class A
        register(B.class)
      }
}