能收到回到通知，但是取不到HTTP响应头，导致获取的签名信息是null,那验签就过不去了；

@PostMapping("/wechatPayNotice")
@ResponseBody
public String payNotify(HttpServletRequest request,
                      HttpServletResponse response) {
    Map<String,String> headers = new HashMap<>();
    String wechatpayTimestamp = response.getHeader("Wechatpay-Timestamp");
    String wechatpayNonce = response.getHeader("Wechatpay-Nonce");
    String wechatpaySerial = response.getHeader("Wechatpay-Serial");
    String wechatpaySignature = response.getHeader("Wechatpay-Signature"）;

为啥我从response取出来的头信息都是null?