private void deleteOne(RoutingContext routingContext) {
   Long id = getId(routingContext);
   if (id == null) {
     routingContext.response().setStatusCode(400).end();
   } else {
     service.remove(id);
   }
   routingContext.response().setStatusCode(204).end();
 }
 private void addOne(RoutingContext routingContext) {
   FactorizationTask task =
       Json.decodeValue(routingContext.getBodyAsString(), FactorizationTask.class);
   task = service.create(task.getNumber());
   routingContext
       .response()
       .setStatusCode(201)
       .putHeader("content-type", "application/json; charset=utf-8")
       .end(Json.encodePrettily(task));
 }
 private void getOne(RoutingContext routingContext) {
   Long id = getId(routingContext);
   if (id == null) {
     routingContext.response().setStatusCode(400).end();
   } else {
     FactorizationTask task = service.getOne(id);
     if (task == null) {
       routingContext.response().setStatusCode(404).end();
     } else {
       routingContext
           .response()
           .putHeader("content-type", "application/json; charset=utf-8")
           // TODO don't serialize null values
           .end(Json.encodePrettily(task));
     }
   }
 }
 private void getAll(RoutingContext routingContext) {
   routingContext
       .response()
       .putHeader("content-type", "application/json; charset=utf-8")
       .end(Json.encodePrettily(service.getAll()));
 }