Get error messages from Spring BindingResult

ValidationUtils.java

public List<String> getErrorMessages(BindingResult bindingResult) {
  return bindingResult.getAllErrors()
    .stream()
    .map(error -> {
      var defaultMessage = error.getDefaultMessage();
      if (error instanceof FieldError) {
        var fieldError = (FieldError) error;
        return String.format("%s %s", fieldError.getField(), defaultMessage);
      } else {
        return defaultMessage;
      }
    })
    .collect(Collectors.toList());
}