Manually call Spring Annotation Validation

Question

I\'m doing a lot of our validation with Hibernate and Spring Annotations like so:

public class Account {
    @NotEmpty(groups = {Step1.class, Step2.class})
          


        

Answer 1

This link gives pretty good examples of using validations in Spring apps. https://reflectoring.io/bean-validation-with-spring-boot/

I have found an example to run the validation programmitically in this article.

class MyValidatingService {

  void validatePerson(Person person) {
    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
    Validator validator = factory.getValidator();
    Set> violations = validator.validate(person);
    if (!violations.isEmpty()) {
      throw new ConstraintViolationException(violations);
    }
  } 
}

It throws 500 status, so it is recommended to handle it with custom exception handler.

@ControllerAdvice(annotations = RestController.class)
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
    @ExceptionHandler(ConstraintViolationException.class)
    public ResponseEntity constraintViolationException(HttpServletResponse response, Exception ex) throws IOException {
        CustomErrorResponse errorResponse = new CustomErrorResponse();
        errorResponse.setTimestamp(LocalDateTime.now());
        errorResponse.setStatus(HttpStatus.BAD_REQUEST.value());
        errorResponse.setError(HttpStatus.BAD_REQUEST.getReasonPhrase());
        errorResponse.setMessage(ex.getMessage());
        return new ResponseEntity<>(errorResponse, HttpStatus.BAD_REQUEST);
    }
}

Second example is from https://www.mkyong.com/spring-boot/spring-rest-error-handling-example/

Update: Using validation is persistence layer is not recommended: https://twitter.com/odrotbohm/status/1055015506326052865