Spring manage http status of custom DTO class without ResponseEntity - spring

Question

public class ApiResponse {
long timestamp;
int status;
String error;
String message;
String path;
public ApiResponse(HttpStatus status, String message) {
super();
this.status = status.value();
this.message = message;
}
}
I have this class and what i want to do is set response status based on status value of ApiResponse object
return new ApiResponse(HttpStatus.CREATED, "Success");
I want response status to be 201.
Is something like this possible?
I know there is ResponseEntity class but i want to handle it without using this class.

Answer 1

Use the ResponseBodyAdvice interface to process the response uniformly.
#RestControllerAdvice
public class TransformStatusBodyAdvice implements ResponseBodyAdvice<ApiResponse> {
#Override
public boolean supports(MethodParameter returnType, Class converterType) {
// check return type is ApiResponse
return returnType.getParameterType().isAssignableFrom(ApiResponse.class);
}
#Override
public ApiResponse beforeBodyWrite(ApiResponse body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
if (body != null) {
// change something if you want
// set the response status code
response.setStatusCode(HttpStatus.valueOf(body.getStatus()));
}
return body;
}
}
Test Controller
#RestController
#RequestMapping("/test")
public class TestController {
#PostMapping
public ApiResponse create() {
return new ApiResponse(HttpStatus.CREATED, "Success");
}
}
Use curl to test result. Now the http response code is 201. If you change your HttpStatus in the ApiResponse, the http status response code will be change.
$ curl -v -X POST http://localhost:8080/test
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> POST /test HTTP/1.1
> ...
>
< HTTP/1.1 201
< Content-Type: application/json
< Transfer-Encoding: chunked
< Date: Mon, 05 Jul 2021 03:45:00 GMT
<
{"timestamp":0,"status":201,"error":null,"message":"Success","path":null}* Connection #0 to host localhost left intact