public static Mono<Void> fail(final String mode, final ServerWebExchange exchange) {
        Object error = Optional.ofNullable(mode)
                .filter(CryptorStrategyFactory.DECRYPT::equals)
                .map(mod -> ShenyuResultWrap.error(exchange, ShenyuResultEnum.DECRYPTION_ERROR))
                .orElse(ShenyuResultWrap.error(exchange, ShenyuResultEnum.ENCRYPTION_ERROR));
        return WebFluxResultUtils.result(exchange, error);
    }
error handling.

@param mode     decrypt or encrypt
@param exchange exchange
@return Mono
shenyu-plugin/shenyu-plugin-security/shenyu-plugin-cryptor/src/main/java/org/apache/shenyu/plugin/cryptor/utils/CryptorUtil.java