2.配置说明
要记住这几个重要的配置

appId 这个是appId
privateKey 商户私钥
publicKey 支付宝公钥, 即对应APPID下的支付宝公钥
notifyUrl 支付成功后异步回调地址(注意是必须是公网地址)
returnUrl #支付后回调地址
signType 签名类型 一般写 RSA2
charset utf-8
format json
#网关地址 在支付宝开发平台复制拷贝下来
gatewayUrl: https://openapi.alipaydev.com/gateway.do
logPath: F:\ 日志路径

（1）在官网注册账户，获取appId，公钥，私钥等信息

（2）引入依赖

（3）编写支付宝配置类

（4）复制官网的生成订单信息代码，导入到自己的项目中

（5）编写支付的业务代码，调用controller接口实现支付

@RequestMapping(value = "/pay", method = RequestMethod.GET)
    // http://localhost:8888/alipay/pay?subject=支付&totalAmount=1&traceNo=1758852777989246976
    public String pay(AliPayDTO aliPayDTO) throws AlipayApiException {
        // 随机一个订单id
//        Random random = new Random();
//        int tradeNo = random.nextInt(1000000);
        //获取订单id
        Long tradeNo = Long.parseLong(aliPayDTO.getTraceNo());
        // 设置请求参数
        AlipayTradePagePayRequest alipayRequest = new AlipayTradePagePayRequest();
        // 同步回调地址
         alipayRequest.setReturnUrl(returnUrl);
        // 异步回调地址
        alipayRequest.setNotifyUrl(notifyUrl);
        // 订单过期时间
        LocalDateTime now = LocalDateTime.now();
        LocalDateTime plusOneMinute = now.plusMinutes(1L);
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String expireTime = plusOneMinute.format(formatter);

        alipayRequest.setBizContent("{\"out_trade_no\":\"" + tradeNo + "\","
                + "\"total_amount\":\"" + aliPayDTO.getTotalAmount() + "\","
                + "\"subject\":\"" + aliPayDTO.getSubject() + "\","
                + "\"body\":\"" + aliPayDTO.getBody() + "\","
                + "\"product_code\":\"FAST_INSTANT_TRADE_PAY\","
                + "\"timeout_express\":\"1m\","                 // 设置订单过期时间为1分钟
                + "\"time_expire\":\"" + expireTime + "\"}");   // 设置订单过期时间
        return alipayClient.pageExecute(alipayRequest).getBody();
    }

    @PostMapping("/notifyUrl")  // 注意这里必须是POST接口
    public String payNotify(HttpServletRequest request) throws MQClientException {
        if (request.getParameter("trade_status").equals("TRADE_SUCCESS")) {
            System.out.println("=========支付宝异步回调========");



            Map<String, String> params = new HashMap<>();
            Map<String, String[]> requestParams = request.getParameterMap();
            for (String name : requestParams.keySet()) {
                params.put(name, request.getParameter(name));
            }
            System.out.println("交易名称: " + params.get("subject"));
            System.out.println("交易状态: " + params.get("trade_status"));
            System.out.println("支付宝交易凭证号: " + params.get("trade_no"));
            System.out.println("商户订单号: " + params.get("out_trade_no"));
            System.out.println("交易金额: " + params.get("total_amount"));
            System.out.println("买家在支付宝唯一id: " + params.get("buyer_id"));
            System.out.println("买家付款时间: " + params.get("gmt_payment"));
            System.out.println("买家付款金额: " + params.get("buyer_pay_amount"));
            Long orderId = Long.parseLong(params.get("out_trade_no"));
            //修改订单状态
            orderService.updateOrder(orderId);

            Order order = ordermapper.queryById(orderId);
            //扣减数据库库存
            productMapper.updateStock(order.getProduct_id(), order.getQuantity());
            //增加积分,自动执行
            //释放锁  redison

        }
        return "success";
    }