@RequestMapping(method = RequestMethod.DELETE, value = "/delete/{id}")
 public void removeEarning(@PathVariable Long id, HttpServletResponse response)
     throws JsonGenerationException, JsonMappingException, IOException {
   log.info("Delete earnings...");
   boolean result = earningsService.removeEarning(id);
   response.setContentType(MediaType.APPLICATION_JSON_VALUE);
   new ObjectMapper().writeValue(response.getOutputStream(), result);
 }
 @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);
 }
 @RequestMapping(method = RequestMethod.GET, value = "/all")
 public void getAllEarnings(HttpServletRequest request, HttpServletResponse response)
     throws JsonGenerationException, JsonMappingException, IOException {
   log.info("Retrieving earnings...");
   List<Earning> l = earningsService.getEarnings();
   log.info("Write JSON in the output stream of the servlet");
   response.setContentType(MediaType.APPLICATION_JSON_VALUE);
   new ObjectMapper().writeValue(response.getOutputStream(), l);
 }