Q:

Spring injection for REST servlet - java.lang.NullPointerException error

I am using Spring injection a REST servlet and it looks like something is going wrong with the injection. This is the error:
01/03/14 11:43:02:260 GMT] 0000001e ContainerResp E   The RuntimeException could not be mapped to a response, re-throwing to the HTTP container                                 java.lang.NullPointerException

A:

You seem to have two problems, not sure which one affects you most.

You're missing an ExceptionMapper that should map exception types on your backend to HTTP responses.
You're getting a NullPointerException, regardless of the fact that the code runs within a REST container. Maybe if you look down to the stack trace of this NullPointerException, you can get a hint on what's going wrong.

