where you are getting null pointer exception exactly, be remember interceptors follow the order how you defined it.
ocjp 6 — Feeding a person with food is a great thing in this world. Feeding the same person by transferring the knowledge is far more better thing. The reason is the amount of satisfaction which we get through food is of only one minute or two. But the satisfaction which we can get through the knowledge is of life long.
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.