为什么调用时报：{"errcode" : 268490003,"errmsg" : "支付签名(pay_sig)校验失败 rid: 69d613a1-399abd25-5f3c9197"}

已经仔细排查了所有可能存在的问题，但问题依旧，生成签名时直接使用JSON字符串，不经过转换也试过了：

String jsonData= "{\"upload_item\":[{\"id\":\"0105\",\"item_url\":\"https://zszb-img.oss-cn-hangzhou.aliyuncs.com/zszb_v3/virtualImages/200X200.png\",\"name\":\"月卡（30天）\",\"price\":770,\"remark\":\"月卡（30天）\"}],\"env\":0}";

最终请求的接口地址为：

https://api.weixin.qq.com/xpay/start_upload_goods?access_token=102_lq4i3abHK0uBgAphxdyXQfVZ_BfgTlxHdYBflnthYBH37lvKmOqhRYGVnp5aDXB_v2KXDGOOaUil7jHsnaIZaic4QWJPIhbE-co8E7LolQ2QnWSy_rQfzGg7HGALFPjADAHBL&pay_sig=a3fbdde931ec17e065612611a41bf96754205940c0f7e01c138bf168aa00b5e5

上传的道具对象：

{
    "upload_item" : [ {
    "id" : "0105",
    "item_url" : "https://zszb-img.oss-cn-hangzhou.aliyuncs.com/zszb_v3/virtualImages/200X200.png",
    "name" : "月卡（30天）",
    "price" : 770,
    "remark" : "月卡（30天）"
    } ],
    "env" : 0
}

上传主方法：

private String uploadGoods(List<UploadGoodsInfo> uploadGoodsInfo,String accessToken,String appKey,int env) {
    Map<String,Object> reqMap = new LinkedHashMap<>();
    reqMap.put("upload_item",uploadGoodsInfo);
    reqMap.put("env",env);
    //生成支付签名
    String jsonData = JSON.toJSONString(reqMap);
    log.info("待签名的数据：{}",jsonData);"remark\":\"月卡（30天）\"}],\"env\":0}";
    String paySig = weiXinPayService.generatePaySign(appKey,"/xpay/start_upload_goods", jsonData);
    String url = BASE_WEIXING_PAY_URL + "start_upload_goods?access_token=" + accessToken + "&pay_sig=" + paySig;
    String resp = HttpUtil.post(url, jsonData);
    log.info("上传结果：{}",resp);
    return resp;
}
支付签名实现：
/**
 * 支付签名
 * @param appKey
 * @param uri
 * @param signData
 * @return
 */
public String generatePaySign(String appKey,String uri,String signData){
    logger.info("signData:{}",signData);
    HMac mac = SecureUtil.hmacSha256(appKey);
    //这里默认使用&拼接，官网示例中使用的是&amp;
    //为了避免歧义，在编写 HTML 代码时，需要把文本中单纯的 “&” 符号写成 &amp;。
    return mac.digestHex(uri +"&" + signData);
}

调用：
UploadGoodsInfo uploadGoodsInfo = new UploadGoodsInfo();
uploadGoodsInfo.setPrice(memberGoodsInfo.getMemberPrice());
uploadGoodsInfo.setId(memberGoodsInfo.getProductId());
uploadGoodsInfo.setName(memberGoodsInfo.getProductName());
uploadGoodsInfo.setRemark(memberGoodsInfo.getProductName());
uploadGoodsInfo.setItem_url("https://zszb-img.oss-cn-hangzhou.aliyuncs.com/zszb_v3/virtualImages/200X200.png");
log.info("正在上传商品：{}",uploadGoodsInfo.getName());
List<UploadGoodsInfo> uploadGoodsInfoList = new ArrayList<>();
uploadGoodsInfoList.add(uploadGoodsInfo);
String resp = uploadGoods(uploadGoodsInfoList,accessToken.getAccess_token(),virtualPayInfo.getAppKey(),virtualPayEnvironment.getVirtualEnvironment());