Diffrence b/w #ResponseStatus and ResponseEntity.created(location).build() in post method of rest controller in spring boot - spring

Question

For a POST method in Rest controller I want to return status code 201.
I saw two approaches for that.
First one is:
#PostMapping("/offers")
#ResponseStatus(HttpStatus.CREATED)
public Offer createOffer(#Valid #RequestBody Offer offer) {
return offerRepository.Save(offer);
}
Second approach is:
#PostMapping("/offers")
public ResponseEntity<Object> createOffer(#Valid #RequestBody Offer offer) {
return offerService.createOffer(offer);
}
Below is my service class:
#Override
public ResponseEntity<Object> createOffer(Offer offer) {
Offer uOffer=OfferRepository.save(offer);
URI location = ServletUriComponentsBuilder.fromCurrentRequest().path("/{jobTitle}").
buildAndExpand(uOffer.getJobTitle()).toUri();
return ResponseEntity.created(location).build();
}
So my question is: for first approach we are not using any ResponseEntity.created as we are simply returning #ResponseStatus(HttpStatus.CREATED) from controller. But in the second we are not using #ResponseStatus(HttpStatus.CREATED) and we are handling that status code 201 by using uri and response entity.
What is the difference b/w the both approaches? Both seems to be same as they are returning the same response code 201. which one is preferred?

Answer 1

In my opinion you should apply the following rules. If you want to return a ResponseEntity then use that to affect the status. Thus something like:
#PostMapping("/offers")
public ResponseEntity<Offer> createOffer(#Valid #RequestBody Offer offer) {
Offer offer = offerService.createOffer(offer);
URI location = ServletUriComponentsBuilder.fromCurrentRequest().path("/{jobTitle}").
buildAndExpand(uOffer.getJobTitle()).toUri();
return ResponseEntity.created(location)
.body(offer)
.build();
}
Do not allow your service to generate the ResponseEntity as this is a view class for controllers and should not be in a service.
The second option is by using the class rather then response entity. Then the example would be something like:
#PostMapping("/offers")
#ResponseStatus(HttpStatus.CREATED)
public Offer createOffer(#Valid #RequestBody Offer offer) {
// Do not return response entity but the offer
return offerService.createOffer(offer);
}

Answer 2

There is no difference in general when it comes to status codes. In the end, you still get an HTTP response with 201 status code.
However, in second approach you're also returning a Location header which is a preferred way to do. From Mozilla's HTTP guide:
The HTTP 201 Created success status response code indicates that the request has succeeded and has led to the creation of a resource. The new resource is effectively created before this response is sent back and the new resource is returned in the body of the message, its location being either the URL of the request, or the content of the Location header.

Answer 3

The first approach is the preferred one, since it allows you to keep your service layer decoupled from your web layer (service layer should not know about HttpEntity and all that stuff, so it could potentially be reused without the web layer).
You should refactor you service method to return Object instead of ResponseEntity<Object>.

Answer 4

What is the difference b/w the both approaches?
Using return ResponseEntity.created(location).build(); adds the Location header to the response.
Is also recommended to return the new resource in the body of the response.
201 Created
The HTTP 201 Created success status response code indicates that the request has succeeded and has led to the creation of a resource. The new resource is effectively created before this response is sent back and the new resource is returned in the body of the message, its location being either the URL of the request, or the content of the Location header.
Thus the best option would be:
ResponseEntity.created(location).body(uOffer);