Not able to return error code with message from rest API in Spring boot

Question

I am new to Spring boot. I have implemented following rest api in Spring boot:

 @GetMapping(value = "/output")
 public ResponseEntity<?> getListOfPOWithItem(@QueryParam("input1") String input1,
                                        @QueryParam("input2") String input2)
                                   throws  BusinessException {
 if (input1 == null) {
  throw new BusinessException("Query param input1 is null or invalid");
 }
 if (input2 == null) {
  throw new BusinessException("Query param input2 is null or invalid");
 }


 List<Output> outputList = 

   myService.getDetails(input1, input2);

   if (outputList != null) {
       return new ResponseEntity<List<Ouput>>(outputList, HttpStatus.OK);
   }
   return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
 }

getDetails() in Myservice is defined as below:

public List<Output> getDetails(String input1, String input2)
      throws BusinessException {
String path = new StringBuilder().append(getBaseUrl()).append("/input1/")
        .append(input1).append("/input2/").append(input2).toString();
try {
  ResponseEntity<List<Output>> responseEntityList = restTemplate.exchange(path,
          HttpMethod.GET, null, new ParameterizedTypeReference<List<Output>>() {});
  List<Output> outputList = responseEntity.getBody();

  if (responseEntityList.isEmpty()) {
    throw new EntityNotFoundException("Input not found",
        ExternalServicesErrorCode.NO_DATA_FOUND);
  }
  return outputList;

} catch (HttpStatusCodeException e) {
  int statusCode = e.getStatusCode().value();

  if (statusCode == Status.NOT_FOUND.getStatusCode()) {
    throw new EntityNotFoundException("Data not found",
        ExternalServicesErrorCode.NO_DATA_FOUND);

  } else {
    throw new BusinessException("Error in getting data", ExternalServicesErrorCode.SERVICE_ERROR);
  }
}

}

Problem is: while invoking this API for invalid inputs, I am getting 500, not 404 and error message "No data found". Can anyone please suggest what change should I make in the above code ?

EDIT: As suggested, I have added following class:

@RestControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

 @ExceptionHandler(Exception.class)
 public final ResponseEntity<ExceptionResponse> 
  handleAllExceptions(Exception ex,
  WebRequest request) {

 ExceptionResponse exceptionResponse = new ExceptionResponse(Instant.now().toEpochMilli(),
    ex.getMessage(), request.getDescription(true));
  return new ResponseEntity<>(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
 }

@ExceptionHandler(EntityNotFoundException.class)
 public final ResponseEntity<ExceptionResponse> handleEntityNotFoundException(
  EntityNotFoundException ex, WebRequest request) {

   ExceptionResponse exceptionResponse = new ExceptionResponse(Instant.now().toEpochMilli(),
    ex.getMessage(), request.getDescription(true));
   return new ResponseEntity<>(exceptionResponse, HttpStatus.NO_CONTENT);
}

Even after that I am unable to get the error code and error message as expected.

Answer 1

As per your controller it uses to throw "BusinessException" exception. But you have not implemented a method to catch that exception in controller adviser which is "GlobalExceptionHandler ". Please include below method in your controller adviser as test was successful.

    @ExceptionHandler(BusinessException.class)
    public ResponseEntity<String> handleBusinessException(BusinessException businessException ) {

        return new ResponseEntity<>("Your specific error", HttpStatus.NOT_FOUND);
    }

Below is the test outcome

Answer 2

Instead of throwing business exception you should create a combined message if both inputs are invalid error message and then you can return a responseEntity as a quick fix:
return new ResponseEntity<>("Invalid input", HttpStatus.NOT_FOUND);

Answer 3

To handle this fix through @RestControllerAdvice , you should create a custom exception which contains the httpStatus Code and the message which you want to return

public class CustomBusinessException extends Exception{

/**
 * 
 */
private static final long serialVersionUID = 1L;

private final String status;
private final String requestMessage;
private final String description;


    public CustomBusinessException (Throwable ex,String status, String requestMessage, String description) {
    super(ex);
    this.status = status;
    this.requestMessage = requestMessage;
    this.description = description;
}
//create getter and setter

}

handle this exception through your custom exception handler(@RestCOntrollerAdvice) and prepare a custom response to be sent like this

@ExceptionHandler({ CustomBusinessException .class })
public ResponseEntity<CustomBusinessResponse> handleAll(CustomBusinessException customBusinessException , WebRequest request) {

    logger.error("Exception occured in NRACustomExceptionHandler :"+ExceptionUtils.getStackTrace(nraGatewayException));
    CustomBusinessResponse response = new CustomBusinessResponse();
    response.setMessage(customBusinessException.getRequestMessage());
    response.setDescription(customBusinessException.getDescription());

    return new ResponseEntity<>(response, new HttpHeaders(), HttpStatus.valueOf(Integer.parseInt(customBusinessException.getStatus())));
}

Create a custom response class

public class NRAExceptionResponse {

private String message;

private String description;


//create getter and setter
}

throw the custom exception with status to be sent like this

  throw new NRAGatewayException(e, "404","Invalid Input", "Invalid input 1 and input 2");