Testing thrown exception in controller

I want to perform a test on a controller method which throws an exception. The method is something like this:

@RequestMapping("/do")
public ResponseEntity doIt(@RequestBody Request request) throws Exception {
    throw new NullPointerException();
}

When I try to test this method with following code part,

 mockMvc.perform(post("/do")
                .contentType(MediaType.APPLICATION_JSON)
                .content(JSON.toJson(request)))

NestedServletException is thrown from Spring libraries. How can I test that NullPointerException is thrown instead of NestedServletException?