code: public static boolean checkSign(PayResultInfo rst, String pubKey) {
  
          if (rst == null || pubKey == null) {
              return false;
          }
  
          Map<String, Object> paramsa = new HashMap<String, Object>();
  
          // 必选参数
          paramsa.put("returnCode", rst.getReturnCode());
          paramsa.put("userName", rst.getUserName());
          paramsa.put("requestId", rst.getRequestId());
          paramsa.put("amount", rst.getAmount());
          paramsa.put("time", rst.getTime());
  
          // 可选参数
          paramsa.put("orderID", rst.getOrderID());
          paramsa.put("withholdID", rst.getWithholdID());
          paramsa.put("errMsg", rst.getErrMsg());
  
          String noSignStr = getNoSign(paramsa, false);
          return doCheck(noSignStr, rst.getSign(), pubKey);
      }
docs: 对支付结果的签名进行校验
  @param rst 支付结果
  @param pubKey 公钥
  @return 是否校验通过