【微信支付】微信小程序支付-V3接口（一）

Dear 丶 2023-10-12 16:09 13阅读 0赞

#### 一.微信小程序接入微信支付流程图： ####

![在这里插入图片描述][0e9350753edb4a82aa1d9f64b4605c78.png]

> 重点步骤说明：  
> 步骤4：用户下单发起支付，商户可通过[JSAPI下单][JSAPI]创建支付订单。  
> 步骤9：商户小程序内使用[小程序调起支付API][API]（wx.requestPayment）发起微信支付，详见小程序API文档  
> 步骤16：用户支付成功后，商户可接收到微信支付支付结果通知[支付通知API][API 1]。  
> 步骤21：商户在没有接收到微信支付结果通知的情况下需要主动调用[查询订单API][API 2]查询支付结果。

#### 二.准备工作: ####

> 官方文档地址：https://pay.weixin.qq.com/wiki/doc/apiv3/open/pay/chapter2\_8\_1.shtml
> 
> 1.  小程序开通微信支付

首先需要在微信支付的官网注册一个商户；  
在管理页面中申请关联小程序,通过小程序的 appid 进行关联；  
进入微信公众平台，功能-微信支付中确认关联（如果服务商和小程序的注册主体不一样，还要经过微信的审核）

> 1.  获取各种证书、密钥文件-基于微信支付 V3 的版本：

商户 id：这个可以在小程序微信公众平台-功能-微信支付 页面中的已关联商户号中得到  
商户密钥：这个需要在微信支付的管理后台中申请获取  
证书编号: 同样在微信支付的管理后台中申请证书，申请证书后就会看到证书编号  
证书私钥：上一步申请证书的时候同时也会获取到证书的公钥、私钥文件。开发中只需要私钥文件

#### 三.后端代码 ####

> 1.引入微信支付官方的pom依赖：

<dependency>
    			<groupId>com.github.wechatpay-apiv3</groupId>
    			<artifactId>wechatpay-apache-httpclient</artifactId>
    			<version>0.4.9</version>
    		</dependency>

> 2.微信支付配置信息：

wx-pay:
      v3:
        #微信关联的小程序的appid
        appId: xxxxx
        #微信支付商户号
        mchId: xxxxxx
        #微信支付证书序列号
        serialnumber: xxxxxx
        #微信支付apiv3的密钥
        apiKey3: xxxxx
        #微信支付证书
        certKeyPath: /cert/xxxxx.pem
        #微信支付回调商户线上地址api
        notifyUrl: https://xxxxx/pay/callback 
        #微信支付关闭订单api
        closeOrderUrl: https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/{
        out_trade_no}/close
        #微信支付小程序预下单api
        jsApiUrl: https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi
        #微信支付订单查询api
        queryOrder: https://api.mch.weixin.qq.com/v3/pay/transactions/id/

@Data
    @Component
    @ConfigurationProperties(prefix="wx-pay.v3")
    public class WxPayConfig {
        
    
        //appId
        private String appId;
    
        //商户id
        private String mchId;
    
        //证书序列号
        private String serialnumber;
    
        //商户秘钥
        private String apiKey3;
    
        //商户的key【API密匙】存放路径
        private String certKeyPath;
    
        //回调通知地址
        private String notifyUrl;
    
        //jsapi预支付url
        private String jsApiUrl;
    
        //关闭订单接口
        private String closeOrderUrl;
    
        //查询订单地址
        private String queryOrder;
    }

> 3.初始化微信支付的参数

@Service
    @Transactional
    public class SysPayServiceImpl implements SysPayService {
        
    	private static final Logger log = LoggerFactory.getLogger(SysPayServiceImpl.class);
        @Autowired
        private WxPayConfig wxPayConfig;
        //微信专业httpClient
        private static CloseableHttpClient httpClient;
        //生成签名用
        private static Sign sign;
        //证书管理器
        private static CertificatesManager certificatesManager;
        @Autowired
        private SysOrderDao sysOrderDao;
    
    	//初始化微信支付的参数
        @PostConstruct
        public void init() throws Exception {
        
            //获取商户私钥
            PrivateKey merchantPrivateKey = PemUtil.loadPrivateKey(getFileInputStream(wxPayConfig.getCertKeyPath()));
            // 获取证书管理器实例
            certificatesManager = CertificatesManager.getInstance();
            sign = SecureUtil.sign(SignAlgorithm.SHA256withRSA, merchantPrivateKey.getEncoded(), null);
            // 向证书管理器增加需要自动更新平台证书的商户信息
            certificatesManager.putMerchant(wxPayConfig.getMchId(), new WechatPay2Credentials(wxPayConfig.getMchId(),
                    new PrivateKeySigner(wxPayConfig.getSerialnumber(), merchantPrivateKey)), wxPayConfig.getApiKey3().getBytes(StandardCharsets.UTF_8));
            // 从证书管理器中获取verifier
            Verifier verifier = certificatesManager.getVerifier(wxPayConfig.getMchId());
            //用于构造HttpClient
            WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create()
                    .withMerchant(wxPayConfig.getMchId(), wxPayConfig.getSerialnumber(), merchantPrivateKey)
                    .withValidator(new WechatPay2Validator(verifier));
            httpClient = builder.build();
        }
     	/**
         * 使用getResourceAsStream直接从resources根路径下获取文件流
         * @param path
         */
        private InputStream getFileInputStream(String path) {
        
            InputStream in = this.getClass().getResourceAsStream(path);
            return in;
        }
    }

> 4.预订单生成返回给小程序请求参数

//预订单生成返回给小程序请求参数
        @Override
        public AjaxResult prePay(WxPayDto dto) {
        
    
            log.info("微信小程序支付JSAPI预下单开始------");
            AjaxResult ajaxResult = AjaxResult.success();
            JSONObject obj = new JSONObject();
            //应用ID
            obj.put("appid", wxPayConfig.getAppId());
            //直连商户号
            obj.put("mchid", wxPayConfig.getMchId());
            //商品描述
            obj.put("description", dto.getDescription());
            //商户订单号
            obj.put("out_trade_no", dto.getOrderCode());
            //通知地址
            obj.put("notify_url", wxPayConfig.getNotifyUrl());
    
            //附加数据 查询API和支付通知中原样返回，可作为自定义参数使用，实际情况下只有支付完成状态才会返回该字段。
            Map<String, String> attach = new HashMap<>();
            attach.put("orderCode", dto.getOrderCode());
            obj.put("attach", JSON.toJSONString(attach));
    
            //订单金额
            JSONObject amount = new JSONObject();
            amount.put("total", dto.getPrice());
            obj.put("amount", amount);
    
            //支付者
            JSONObject payer = new JSONObject();
            payer.put("openid", dto.getOpenId());
            obj.put("payer", payer);
    
            log.info("微信小程序支付JSAPI预下单请求参数:{}" + obj.toJSONString());
    
            HttpPost httpPost = new HttpPost(wxPayConfig.getJsApiUrl());
            httpPost.addHeader("Accept", "application/json");
            httpPost.addHeader("Content-type", "application/json; charset=utf-8");
            httpPost.setEntity(new StringEntity(obj.toJSONString(), "UTF-8"));
    
            String bodyAsString ;
            try {
        
                if(httpClient == null){
        
                    log.info("微信小程序支付JSAPI预下单请求失败");
                    return AjaxResult.error("预下单失败，请重试,无法连接微信支付服务器!" );
                }
                //执行请求
                CloseableHttpResponse response = httpClient.execute(httpPost);
                bodyAsString = EntityUtils.toString(response.getEntity());
            } catch (IOException e) {
        
                log.info("微信小程序支付JSAPI预下单请求失败{}", e.getMessage());
                return AjaxResult.error("预下单失败，请重试！" + e.getMessage());
            }
            String prePayId = JSONObject.parseObject(bodyAsString).getString("prepay_id");
            if (prePayId == null){
        
                String message = JSONObject.parseObject(bodyAsString).getString("message");
                log.info("微信小程序支付JSAPI预下单请求失败{}", message);
                return AjaxResult.error("预下单失败，请重试！" + message);
            }
            //准备小程序端的请求参数
            ajaxResult.put("appId", wxPayConfig.getAppId());
            String timeStamp = String.valueOf(System.currentTimeMillis() / 1000);
            ajaxResult.put("timeStamp", timeStamp);
            String nonceStr = IdUtil.fastSimpleUUID();
            ajaxResult.put("nonceStr", nonceStr);
            String packageStr = "prepay_id=" + prePayId;
            ajaxResult.put("package", packageStr);
            ajaxResult.put("signType", "RSA");
            String signString =  wxPayConfig.getAppId() + "\n" + timeStamp + "\n" + nonceStr + "\n" + packageStr + "\n";
            ajaxResult.put("paySign", Base64.encode(sign.sign(signString.getBytes())));
            return ajaxResult;
        }

> 5.微信支付回调通知

//微信支付回调通知
        @Override
        public void callback(HttpServletRequest servletRequest, HttpServletResponse response) {
        
            log.info("----------->微信支付回调开始");
            Map<String, String> map = new HashMap<>(12);
            String timeStamp = servletRequest.getHeader("Wechatpay-Timestamp");
            String nonce = servletRequest.getHeader("Wechatpay-Nonce");
            String signature = servletRequest.getHeader("Wechatpay-Signature");
            String certSn = servletRequest.getHeader("Wechatpay-Serial");
    
            try (BufferedReader reader = new BufferedReader(new InputStreamReader(servletRequest.getInputStream()))) {
        
                StringBuilder stringBuilder = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
        
                    stringBuilder.append(line);
                }
                String obj = stringBuilder.toString();
                log.info("微信支付回调请求参数:{},{},{},{},{}", obj, timeStamp, nonce, signature, certSn);
    
                Verifier verifier = certificatesManager.getVerifier(wxPayConfig.getMchId());
                String sn = verifier.getValidCertificate().getSerialNumber().toString(16).toUpperCase(Locale.ROOT);
                NotificationRequest request = new NotificationRequest.Builder().withSerialNumber(sn)
                        .withNonce(nonce)
                        .withTimestamp(timeStamp)
                        .withSignature(signature)
                        .withBody(obj)
                        .build();
                NotificationHandler handler = new NotificationHandler(verifier, wxPayConfig.getApiKey3().getBytes(StandardCharsets.UTF_8));
                // 验签和解析请求体
                Notification notification = handler.parse(request);
                JSONObject res = JSON.parseObject(notification.getDecryptData());
                log.info("微信支付回调响应参数:{}", res.toJSONString());
    
                //做一些操作
                if (res != null) {
        
                    //如果支付成功
                    String tradeState = res.getString("trade_state");
                    if("SUCCESS".equals(tradeState)){
        
                        //拿到商户订单号
                        String outTradeNo = res.getString("out_trade_no");
                        JSONObject amountJson = res.getJSONObject("amount");
                        Integer payerTotal = amountJson.getInteger("payer_total");
                        SysOrder sysOrder = sysOrderDao.queryByOrderCode(outTradeNo);
                        if(sysOrder != null){
        
                            if(sysOrder.getPayStatus() == 1){
        
                                //如果支付状态为1 说明订单已经支付成功了,直接响应微信服务器返回成功
                                response.setStatus(200);
                                map.put("code", "SUCCESS");
                                map.put("message", "SUCCESS");
                                response.setHeader("Content-type", ContentType.JSON.toString());
                                response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
                                response.flushBuffer();
                            }
                            //验证用户支付的金额和订单金额是否一致
                            if(payerTotal.equals(sysOrder.getOrderPrice())){
        
                                //修改订单状态
                                String successTime = res.getString("success_time");
                                sysOrder.setPayStatus(1);
                                sysOrderDao.update(sysOrder);
                                //响应微信服务器
                                response.setStatus(200);
                                map.put("code", "SUCCESS");
                                map.put("message", "SUCCESS");
                                response.setHeader("Content-type", ContentType.JSON.toString());
                                response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
                                response.flushBuffer();
                            }
                        }
                    }
                }
                response.setStatus(500);
                map.put("code", "ERROR");
                map.put("message", "签名错误");
                response.setHeader("Content-type", ContentType.JSON.toString());
                response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
                response.flushBuffer();
            } catch (Exception e) {
        
                log.error("微信支付回调失败", e);
            }
        }

> 6.当用户10分钟内未支付，系统自动关闭微信支付订单并删除

//当用户10分钟内未支付，系统自动关闭微信支付订单并删除
        @Override
        public void deleteClosePayOrder(String orderCode) {
        
            JSONObject obj = new JSONObject();
            //直连商户号
            obj.put("mchid", wxPayConfig.getMchId());
    
            String ret2 = wxPayConfig.getCloseOrderUrl().replace("{out_trade_no}", orderCode);
    
            log.info("关闭和删除微信订单--请求地址{}" , ret2);
    
            log.info("关闭和删除微信订单--请求参数{}" , obj.toJSONString());
            HttpPost httpPost = new HttpPost(ret2);
            httpPost.addHeader("Accept", "application/json");
            httpPost.addHeader("Content-type", "application/json; charset=utf-8");
            httpPost.setEntity(new StringEntity(obj.toJSONString(), "UTF-8"));
    
            String bodyAsString ;
            try {
        
                if(httpClient == null){
        
                    log.info("关闭和删除微信订单--关闭订单失败，请重试,无法连接微信支付服务器!");
                }
                //执行请求
                CloseableHttpResponse response = httpClient.execute(httpPost);
                //状态码
                int statusCode = response.getStatusLine().getStatusCode();
                if (statusCode == 204) {
        
                    //关闭订单成功!
                    //删除订单
                    log.info("关闭和删除微信订单--关闭订单成功orderCode:{}!", orderCode);
                    sysOrderDao.deleteByOrderCode(orderCode);
                }else if(statusCode == 202){
        
                    //用户支付中，需要输入密码
                    log.info("关闭和删除微信订单--用户支付中，需要输入密码,暂时不做处理!");
                }else{
        
                    log.info("关闭和删除微信订单--关闭支付订单失败，出现未知原因{}", EntityUtils.toString(response.getEntity()));
                }
            } catch (IOException e) {
        
                log.info("关闭和删除微信订单--关闭订单失败{}", e.getMessage());
            }
        }

> 7.查询订单支付结果接口

//查询订单支付结果
        @Override
        public AjaxResult queryPayResult(String payId){
        
    
            //请求URL
            URIBuilder uriBuilder = null;
            try {
        
                uriBuilder = new URIBuilder(wxPayConfig.getQueryOrder() + payId);
                uriBuilder.setParameter("mchid", wxPayConfig.getMchId());
                if(httpClient == null){
        
                    return AjaxResult.error("查询订单失败，请重试,无法连接微信支付服务器!" );
                }
                //完成签名并执行请求
                HttpGet httpGet = new HttpGet(uriBuilder.build());
                httpGet.addHeader("Accept", "application/json");
                CloseableHttpResponse response = httpClient.execute(httpGet);
    
                int statusCode = response.getStatusLine().getStatusCode();
                if (statusCode == 200 || statusCode == 204) {
        
                    String ss = EntityUtils.toString(response.getEntity());
                    if(StringUtils.isNotEmpty(ss)){
        
                        JSONObject res = JSON.parseObject(ss);
                        log.info("success,return body = " + ss);
                        //拿到商户订单号
                        String outTradeNo = res.getString("out_trade_no");
                        JSONObject amountJson = res.getJSONObject("amount");
                        Integer payerTotal = amountJson.getInteger("payer_total");
                        SysOrder sysOrder = sysOrderDao.queryByOrderCode(outTradeNo);
                        if(sysOrder != null){
        
                            if(sysOrder.getPayStatus() == 1){
        
                                //如果支付状态为1 说明订单已经支付成功了,直接响应成功
                                return AjaxResult.success("查询支付成功!" );
                            }
                            //验证用户支付的金额和订单金额是否一致
                            if(payerTotal.equals(sysOrder.getOrderPrice())){
        
                                //修改订单状态
                                String successTime = res.getString("success_time");
                                sysOrder.setPayStatus(1);
                                sysOrderDao.update(sysOrder);
                                return AjaxResult.success("查询支付成功!");
                            }
                        }
                    }
                }
                return AjaxResult.error("查询支付失败:" + "failed,resp code = " + statusCode+ ",return body = " + EntityUtils.toString(response.getEntity()));
            } catch (Exception e) {
        
                return AjaxResult.error("查询支付失败:" + e.getMessage());
            }
        }

#### 四.前端小程序代码 ####

> 微信小程序支付需要用到官方的支付API：wx.requestPayment(Object object)  
> 官方文档地址:https://developers.weixin.qq.com/miniprogram/dev/api/payment/wx.requestPayment.html

wx.requestPayment({
        
                timeStamp: 'xxx',   // 时间戳，从 1970 年 1 月 1 日 00:00:00 至今的秒数，即当前的时间
                nonceStr: 'xxxxxx',   // 随机字符串，长度为32个字符以下
                package: 'xxxxxxxxxxxx',  // 统一下单接口返回的 prepay_id 参数值，提交格式如：prepay_id=***
                signType: 'xxx',  // 签名算法，应与后台下单时的值一致
                paySign: 'xxxxxxxxxx', // 签名，具体见微信支付文档
                success (res) {
         // 成功的回调
                    wx.showToast({
        title: '付款成功'})
                }, 
                fail (res) {
         // 失败的回调
                    wx.showToast({
        title: '支付失败',icon: 'none'})
                }
              })
    })

[0e9350753edb4a82aa1d9f64b4605c78.png]: https://img-blog.csdnimg.cn/0e9350753edb4a82aa1d9f64b4605c78.png
[JSAPI]: https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_5_1.shtml
[API]: https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_5_4.shtml
[API 1]: https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_5_5.shtml
[API 2]: https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_5_2.shtml