Day-08

微信支付

在项目中，支付方式选择小程序的微信支付。

微信小程序支付时序图（微信开发文档提供）

详见开发指引-小程序支付 | 微信支付商户平台文档中心 (qq.com)

获取临时域名

即获取一个公网IP

下载安装cpolar软件

业务功能

微信支付

（1）完成相关配置

（2）service层代码

 	@Autowired
    private UserMapper userMapper;
    // 微信支付工具类，包括获取调用微信接口的客户端工具对象、jsapi下单、小程序支付、申请退款等方法
	@Autowired
    private WeChatPayUtil weChatPayUtil;

    /**
     * 订单支付
     *
     * @param ordersPaymentDTO
     * @return
     */
    public OrderPaymentVO payment(OrdersPaymentDTO ordersPaymentDTO) throws Exception {
        // 当前登录用户id
        Long userId = BaseContext.getCurrentId();
        User user = userMapper.getById(userId);

        //调用微信支付接口，生成预支付交易单
        JSONObject jsonObject = weChatPayUtil.pay(
                ordersPaymentDTO.getOrderNumber(), //商户订单号
                new BigDecimal(0.01), //支付金额，单位 元
                "苍穹外卖订单", //商品描述
                user.getOpenid() //微信用户的openid
        );

        if (jsonObject.getString("code") != null && jsonObject.getString("code").equals("ORDERPAID")) {
            throw new OrderBusinessException("该订单已支付");
        }

        OrderPaymentVO vo = jsonObject.toJavaObject(OrderPaymentVO.class);
        vo.setPackageStr(jsonObject.getString("package"));

        return vo;
    }

    /**
     * 支付成功，修改订单状态
     *
     * @param outTradeNo
     */
    public void paySuccess(String outTradeNo) {
        // 当前登录用户id
        Long userId = BaseContext.getCurrentId();

        // 根据订单号查询当前用户的订单
        Orders ordersDB = orderMapper.getByNumberAndUserId(outTradeNo, userId);

        // 根据订单id更新订单的状态、支付方式、支付状态、结账时间
        Orders orders = Orders.builder()
                .id(ordersDB.getId())
                .status(Orders.TO_BE_CONFIRMED)
                .payStatus(Orders.PAID)
                .checkoutTime(LocalDateTime.now())
                .build();

        orderMapper.update(orders);
    }

（3）微信支付工具类

/**
 * 微信支付工具类
 */
@Component
public class WeChatPayUtil {

    //微信支付下单接口地址
    public static final String JSAPI = "https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi";

    //申请退款接口地址
    public static final String REFUNDS = "https://api.mch.weixin.qq.com/v3/refund/domestic/refunds";

    @Autowired
    private WeChatProperties weChatProperties;

    /**
     * 获取调用微信接口的客户端工具对象
     *
     * @return
     */
    private CloseableHttpClient getClient() {
        PrivateKey merchantPrivateKey = null;
        try {
            //merchantPrivateKey商户API私钥，如何加载商户API私钥请看常见问题
            merchantPrivateKey = PemUtil.loadPrivateKey(new FileInputStream(new File(weChatProperties.getPrivateKeyFilePath())));
            //加载平台证书文件
            X509Certificate x509Certificate = PemUtil.loadCertificate(new FileInputStream(new File(weChatProperties.getWeChatPayCertFilePath())));
            //wechatPayCertificates微信支付平台证书列表。你也可以使用后面章节提到的“定时更新平台证书功能”，而不需要关心平台证书的来龙去脉
            List wechatPayCertificates = Arrays.asList(x509Certificate);

            WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create()
                    .withMerchant(weChatProperties.getMchid(), weChatProperties.getMchSerialNo(), merchantPrivateKey)
                    .withWechatPay(wechatPayCertificates);

            // 通过WechatPayHttpClientBuilder构造的HttpClient，会自动的处理签名和验签
            CloseableHttpClient httpClient = builder.build();
            return httpClient;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 发送post方式请求
     *
     * @param url
     * @param body
     * @return
     */
    private String post(String url, String body) throws Exception {
        CloseableHttpClient httpClient = getClient();

        HttpPost httpPost = new HttpPost(url);
        httpPost.addHeader(HttpHeaders.ACCEPT, ContentType.APPLICATION_JSON.toString());
        httpPost.addHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString());
        httpPost.addHeader("Wechatpay-Serial", weChatProperties.getMchSerialNo());
        httpPost.setEntity(new StringEntity(body, "UTF-8"));

        CloseableHttpResponse response = httpClient.execute(httpPost);
        try {
            String bodyAsString = EntityUtils.toString(response.getEntity());
            return bodyAsString;
        } finally {
            httpClient.close();
            response.close();
        }
    }

    /**
     * 发送get方式请求
     *
     * @param url
     * @return
     */
    private String get(String url) throws Exception {
        CloseableHttpClient httpClient = getClient();

        HttpGet httpGet = new HttpGet(url);
        httpGet.addHeader(HttpHeaders.ACCEPT, ContentType.APPLICATION_JSON.toString());
        httpGet.addHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString());
        httpGet.addHeader("Wechatpay-Serial", weChatProperties.getMchSerialNo());

        CloseableHttpResponse response = httpClient.execute(httpGet);
        try {
            String bodyAsString = EntityUtils.toString(response.getEntity());
            return bodyAsString;
        } finally {
            httpClient.close();
            response.close();
        }
    }

    /**
     * jsapi下单
     *
     * @param orderNum    商户订单号
     * @param total       总金额
     * @param description 商品描述
     * @param openid      微信用户的openid
     * @return
     */
    private String jsapi(String orderNum, BigDecimal total, String description, String openid) throws Exception {
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("appid", weChatProperties.getAppid());
        jsonObject.put("mchid", weChatProperties.getMchid());
        jsonObject.put("description", description);
        jsonObject.put("out_trade_no", orderNum);
        jsonObject.put("notify_url", weChatProperties.getNotifyUrl());

        JSONObject amount = new JSONObject();
        amount.put("total", total.multiply(new BigDecimal(100)).setScale(2, BigDecimal.ROUND_HALF_UP).intValue());
        amount.put("currency", "CNY");

        jsonObject.put("amount", amount);

        JSONObject payer = new JSONObject();
        payer.put("openid", openid);

        jsonObject.put("payer", payer);

        String body = jsonObject.toJSONString();
        return post(JSAPI, body);
    }

    /**
     * 小程序支付
     *
     * @param orderNum    商户订单号
     * @param total       金额，单位 元
     * @param description 商品描述
     * @param openid      微信用户的openid
     * @return
     */
    public JSONObject pay(String orderNum, BigDecimal total, String description, String openid) throws Exception {
        //统一下单，生成预支付交易单
        String bodyAsString = jsapi(orderNum, total, description, openid);
        //解析返回结果
        JSONObject jsonObject = JSON.parseObject(bodyAsString);
        System.out.println(jsonObject);

        String prepayId = jsonObject.getString("prepay_id");
        if (prepayId != null) {
            String timeStamp = String.valueOf(System.currentTimeMillis() / 1000);
            String nonceStr = RandomStringUtils.randomNumeric(32);
            ArrayList