how to properly send a header and a status code

gistfile1.txt

    @RequestMapping(value = USER_COLLECTION_URL, method = RequestMethod.POST)
    public ResponseEntity<User> registerUser(@RequestParam("username") String username,
                                             @RequestParam("password") String password,
                                             @RequestParam("firstname") String fn,
                                             @RequestParam("lastname") String ln,
                                             @RequestParam("imported") boolean importedFromServiceProvider,
                                             UriComponentsBuilder componentsBuilder) throws Throwable {

        User user = this.userService.createOrGet(username, password, fn, ln, importedFromServiceProvider);

        UriComponents uriComponents = componentsBuilder.path(USER_COLLECTION_ENTRY_URL).buildAndExpand(user.getId());

        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setLocation(uriComponents.toUri());

        return new ResponseEntity<User>(user, httpHeaders, HttpStatus.CREATED);
    }