case FILE -> ComponentUtil.getFessConfig().getCrawlerFileProtocolsAsArray();
        default -> throw new ConstraintDefinitionException("protocolType is emtpy.");
        };
    }

    @Override
    public boolean isValid(final String value, final ConstraintValidatorContext context) {
        if (StringUtil.isNotBlank(value)) {
            return check(protocols, value);
        }
        return true;
    }