Changing a 404 response for REST API to a 200 empty response

Question

I have a Spring Boot application written in Java that is a REST API. This service (Svc A) calls a REST API service (Svc B) with is also a Spring Boot Application written in Java. Svc B returns a 404 status code when no data was found. I need to change this response to a 200 status code and return an empty response object. I am not sure if or how to do this.

I can catch the error and determine if the 404 is this no data found error. However, I don't know how to change the response to a 200 empty response. I am using a FeignClient to call the service. This is the error code that catches the 404:

@Component
public class FeignErrorDecoder implements ErrorDecoder {

    Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public Exception decode(String methodKey, Response response) {
        Reader reader = null;
        String messageText = null;
        switch (response.status()){
            case 400:
                logger.error("Status code " + response.status() + ", methodKey = " + methodKey);
            case 404:
            {
                logger.error("Error took place when using Feign client to send HTTP Request. Status code " + response.status() + ", methodKey = " + methodKey);
                try {
                    reader = response.body().asReader();
                    //Easy way to read the stream and get a String object
                    String result = CharStreams.toString(reader);
                    logger.error("RESPONSE BODY: " + result);
                    ObjectMapper mapper = new ObjectMapper();
                    //just in case you missed an attribute in the Pojo
                    mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
                    //init the Pojo
                    ExceptionMessage exceptionMessage = mapper.readValue(result,
                            ExceptionMessage.class);

                    messageText = exceptionMessage.getMessage();
                    logger.info("message: " + messageText);

                } catch(IOException ex) {
                    logger.error(ex.getMessage());
                }
                finally {
                    try {

                        if (reader != null)
                            reader.close();

                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

                return new ResponseStatusException(HttpStatus.valueOf(200), messageText);
            }
            default:
                return new Exception(response.reason());
        }
    }
}

I can change the status code to a 200 and it returns a 200 but I need to the response to have an empty response object. The above code will return this response body of an error response object:

{
   "statusCd" : "200",
   "message" : "The Location not found for given Location Number and Facility Type Code",
   "detailDesc" : "The Location not found for given Location Number and Facility Type Code. Error Timestamp : 2020-01-31 18:19:13"
}

I need it to return a response body like this: 200 - Empty Response

{
  "facilityNumber": "923",
  "facilityTimeZone": null,
  "facilityAbbr": null,
  "scheduledOperations": []
}

Answer 1

如果 404 只是尝试

return new ResponseStatusException(HttpStatus.valueOf(200));

Answer 2

For anyone that has to do something this crazy...here is my solution: Removed the FeignErrorCode file. Added an exception to ControllerAdvice class like this:

@ExceptionHandler(FeignException.class)
    public ResponseEntity<?> handleFeignException(FeignException fe, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(new Date(), HttpStatus.valueOf(fe.status()), fe.getMessage(), request.getDescription(false));
        String response = fe.contentUTF8();

        if(response != null) {
            ScheduledOperationsViewResponse scheduledOperationsViewResponse = new ScheduledOperationsViewResponse();
            if (response.contains("Scheduled") || response.contains("Location")) {
                HttpHeaders headers = new HttpHeaders();
                scheduledOperationsViewResponse.setFacilityNumber(request.getParameter("facilityNumber"));
                return new ResponseEntity<ScheduledOperationsViewResponse>(scheduledOperationsViewResponse, headers, HttpStatus.OK);
            }
        }
        return new ResponseEntity<>(errorDetails, errorDetails.getStatus());
    }