Return response messages in spring boot - spring-boot

Question

I am working with spring boot with a h2 database. I would like to return a 201 message when the register is inserted succesfully and a 400 when is duplicated. I am using ResponseEntity to achieve this, fot example , the next is my create method from the Service:
#Override
public ResponseEntity<Object> createEvent(EventDTO eventDTO) {
if (eventRepository.findOne(eventDTO.getId()) != null) {
//THis is a test, I am looking for the correct message
return new ResponseEntity(HttpStatus.IM_USED);
}
Actor actor = actorService.createActor(eventDTO.getActor());
Repo repo = repoService.createRepo(eventDTO.getRepo());
Event event = new Event(eventDTO.getId(), eventDTO.getType(), actor, repo, createdAt(eventDTO));
eventRepository.save(event);
return new ResponseEntity(HttpStatus.CREATED);
}
This is my controller:
#PostMapping(value = "/events")
public ResponseEntity addEvent(#RequestBody EventDTO body) {
return eventService.createEvent(body);
}
But I'm not getting any message in the browser, I am doing different tests with postman and when I consult for all the events, the result is correct, but each time that I make a post I dont get any message in the browser, I am not pretty sure what is the cause of this issue. Any ideas?

Answer 1

The ideal way to send Response to the client is to create DTO/DAO with ResponseEntity in Controller
Controller.java
#PostMapping("/test")
public ResponseEntity<Object> testApi(#RequestBody User user)
{
System.out.println("User: "+user.toString());
return assetService.testApi(user);
}
Service.java
public ResponseEntity testApi(User user) {
if(user.getId()==1)
return new ResponseEntity("Created",HttpStatus.CREATED);
else
return new ResponseEntity("Used",HttpStatus.IM_USED);
// for BAD_REQUEST(400) return new ResponseEntity("Bad Request",HttpStatus.BAD_REQUEST);
}
Tested using Postman
Status 201 Created
Status 226 IM Used

Answer 2

Okay, I really don't feel good that service sending the ResponseEntity but not Controller.You could use #ResponseStatus and ExceptionHandler classes for these cases, like below.
Create a class in exception package
GlobalExceptionHandler.java
#ControllerAdvice
public class GlobalExceptionHandler {
#ResponseStatus(HttpStatus.BAD_REQUEST)
#ExceptionHandler(DataIntegrityViolationException.class) // NOTE : You could create a custom exception class to handle duplications
public void handleConflict() {
}
}
Controller.java
#PostMapping(value = "/events")
#ResponseStatus(HttpStatus.CREATED) // You don't have to return any object this will take care of the status
public void addEvent(#RequestBody EventDTO body) {
eventService.createEvent(body);
}
Now changing the service would look like,
Service.java
#Override
public void createEvent(EventDTO eventDTO) { // No need to return
if (eventRepository.findOne(eventDTO.getId()) != null) {
throw new DataIntegrityViolationException("Already exists"); // you have to throw the same exception which you have marked in Handler class
}
Actor actor = actorService.createActor(eventDTO.getActor());
Repo repo = repoService.createRepo(eventDTO.getRepo());
Event event = new Event(eventDTO.getId(), eventDTO.getType(), actor, repo, createdAt(eventDTO));
eventRepository.save(event);
}