@RequestMapping(method = RequestMethod.PUT, value = "/add/{label}/{amount}")
 public void addEarning(
     @PathVariable String label, @PathVariable int amount, HttpServletResponse response)
     throws JsonGenerationException, JsonMappingException, IOException {
   log.info("Add new earnings...");
   long id = earningsService.addEarning(label, amount, null);
   response.setContentType(MediaType.APPLICATION_JSON_VALUE);
   new ObjectMapper().writeValue(response.getOutputStream(), id);
 }