Spring Boot how to return my own validation constraint error messages
If this can help, I found the solution for this issue here: https://howtodoinjava.com/spring-boot2/spring-rest-request-validation/
You have to add this method to your CustomResponseEntityExceptionHandler class:
@Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
List<String> details = new ArrayList<>();
for(ObjectError error : ex.getBindingResult().getAllErrors()) {
details.add(error.getDefaultMessage());
}
ErrorMessage error = new ErrorMessage(new Date(), details.toString());
return new ResponseEntity<>(error, HttpStatus.BAD_REQUEST);
}
Yes it is doable & spring very well supports it. You are just missing some configuration to enable it in spring.
- Use Spring
@Validated
annotation to enable spring to validate controller- Handle
ConstraintViolationException
in yourControllerAdvice
to catch all failed validation messages.- Mark
required=false
in@RequestParam
, so it will not throw MissingServletRequestParameterException and rather move to next step of constraint validation.
@ControllerAdvice
public class CustomResponseEntityExceptionHandler {
@ExceptionHandler
public ResponseEntity<ApiError> handle(ConstraintViolationException exception) {
//you will get all javax failed validation, can be more than one
//so you can return the set of error messages or just the first message
String errorMessage = new ArrayList<>(exception.getConstraintViolations()).get(0).getMessage();
ApiError apiError = new ApiError(errorMessage, errorMessage, 1000);
return new ResponseEntity<ApiError>(apiError, null, HttpStatus.BAD_REQUEST);
}
}
@RestController
@Validated
public class MinimumStockController {
@RequestMapping(value = "/minimumstock")
public Product product(
@RequestParam(value = "product.sku", required=false) @NotEmpty(message = "Product.sku cannot be empty") String sku,
@RequestParam(value = "stock.branch.id", required=false) String branchID) {
return null;
}
}
NOTE: MissingServletRequestParameterException
won't have access to javax validation messages, as it is thrown before constraint validation occurs in the request lifecycle.