@POST
 @Consumes(MediaType.APPLICATION_JSON)
 @Produces(MediaType.APPLICATION_JSON)
 @Path("producers")
 public Producer saveProducer(Producer producer) throws BusinessException {
   if (producer.getId() == null) {
     return wineServiceFacade.saveProducer(producer);
   }
   throw new RuntimeException();
 }
 @POST
 @Consumes(MediaType.APPLICATION_JSON)
 @Produces(MediaType.APPLICATION_JSON)
 @Path("producers/{id}")
 public Producer saveProducer(@PathParam("id") int id, Producer producer)
     throws BusinessException {
   if ((id == producer.getId()) && (wineServiceFacade.getProducerById(id) != null)) {
     return wineServiceFacade.saveProducer(producer);
   }
   throw new RuntimeException();
 }