Spring Boot Rest Controller how to return different HTTP status codes? - spring

Question

I am using Spring Boot for a simple REST API and would like to return a correct HTTP statuscode if something fails.
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
#ResponseBody
#ResponseStatus( HttpStatus.OK )
public RestModel create(#RequestBody String data) {
// code ommitted..
// how do i return a correct status code if something fails?
}
Being new to Spring and Spring Boot, the basic question is how do i return different status codes when something is ok or fails?

Answer 1

There are several options you can use. Quite good way is to use exceptions and class for handling called #ControllerAdvice:
#ControllerAdvice
class GlobalControllerExceptionHandler {
#ResponseStatus(HttpStatus.CONFLICT) // 409
#ExceptionHandler(DataIntegrityViolationException.class)
public void handleConflict() {
// Nothing to do
}
}
Also you can pass HttpServletResponse to controller method and just set response code:
public RestModel create(#RequestBody String data, HttpServletResponse response) {
// response committed...
response.setStatus(HttpServletResponse.SC_ACCEPTED);
}
Please refer to the this great blog post for details: Exception Handling in Spring MVC
NOTE
In Spring MVC using #ResponseBody annotation is redundant - it's already included in #RestController annotation.

Answer 2

One of the way to do this is you can use ResponseEntity as a return object.
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
public ResponseEntity<?> create(#RequestBody String data) {
if(everything_fine) {
return new ResponseEntity<>(RestModel, HttpStatus.OK);
} else {
return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
}
}

Answer 3

A nice way is to use Spring's ResponseStatusException
Rather than returning a ResponseEntityor similar you simply throw the ResponseStatusException from the controller with an HttpStatus and cause, for example:
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Cause description here");
This results in a response to the client containing the HTTP status:
{
"timestamp": "2020-07-09T04:43:04.695+0000",
"status": 400,
"error": "Bad Request",
"message": "Cause description here",
"path": "/test-api/v1/search"
}
Note: HttpStatus provides many different status codes for your convenience.

Answer 4

In case you want to return a custom defined status code, you can use the ResponseEntity as here:
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
public ResponseEntity<?> create(#RequestBody String data) {
int customHttpStatusValue = 499;
Foo foo = bar();
return ResponseEntity.status(customHttpStatusValue).body(foo);
}
The CustomHttpStatusValue could be any integer within or outside of standard HTTP Status Codes.

Answer 5

Try this code:
#RequestMapping(value = "/validate", method = RequestMethod.GET, produces = "application/json")
public ResponseEntity<ErrorBean> validateUser(#QueryParam("jsonInput") final String jsonInput) {
int numberHTTPDesired = 400;
ErrorBean responseBean = new ErrorBean();
responseBean.setError("ERROR");
responseBean.setMensaje("Error in validation!");
return new ResponseEntity<ErrorBean>(responseBean, HttpStatus.valueOf(numberHTTPDesired));
}

Answer 6

There are different ways to return status code,
1 : RestController class should extends BaseRest class, in BaseRest class we can handle exception and return expected error codes.
for example :
#RestController
#RequestMapping
class RestController extends BaseRest{
}
#ControllerAdvice
public class BaseRest {
#ExceptionHandler({Exception.class,...})
#ResponseStatus(value=HttpStatus.INTERNAL_SERVER_ERROR)
public ErrorModel genericError(HttpServletRequest request,
HttpServletResponse response, Exception exception) {
ErrorModel error = new ErrorModel();
resource.addError("error code", exception.getLocalizedMessage());
return error;
}

Answer 7

I think the easiest way is to make return type of your method as
ResponseEntity<WHATEVER YOU WANT TO RETURN>
and for sending any status code, just add return statement as
return ResponseEntity.status(HTTP STATUS).build();
For example, if you want to return a list of books,
public ResponseEntity<List<books>> getBooks(){
List<books> list = this.bookService.getAllBooks();
if(list.size() <= 0)
return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
else
return ResponseEntity.of(Optional.of(list));
}