Java 实现微信支付详细教程

刺骨的言语ヽ痛彻心扉 2023-10-13 15:47 20阅读 0赞

**摘要**：最近的一个项目中涉及到了支付业务，其中用到了微信支付和支付宝支付，在做的过程中也遇到些问题，所以现在总结梳理一下，分享给有需要的人，也为自己以后回顾留个思路。

### 一、微信支付接入准备工作： ###

首先，微信支付，只支持企业用户，个人用户是不能接入微信支付的，所以要想接入微信支付，首先需要有微信公众号，这个的企业才能申请。有了微信公众号，就能申请微信支付的相关内容，所以在准备开始写代码之前需要先把下面的这些参数申请好：公众账号ID、微信支付商户号、API密钥、AppSecret是APPID对应的接口密码、回调地址(回调必须保证外网能访问到此地址)、发起请求的电脑IP

## 二、微信支付流程说明： ##

有了上面提到的这些参数，那我们就可以接入微信支付了，下面我来看下微信支付的官方文档（https://pay.weixin.qq.com/wiki/doc/api/index.html）、访问该地址可以看到有多种支付方式可以选择，我们这里选择扫码支付的方式(https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=6\_1)

这里我们选择模式二，下面看下模式二的时序图，如下图：

模式二与模式一相比，流程更为简单，不依赖设置的回调支付URL。商户后台系统先调用微信支付的统一下单接口，微信后台系统返回链接参数code\_url，商户后台系统将code\_url值生成二维码图片，用户使用微信客户端扫码后发起支付。注意：code\_url有效期为2小时，过期后扫码不能再发起支付。

![在这里插入图片描述][ae7c841c56f04b4c986cc3668e10b0c4.png]

## 三、微信支付所需Maven依赖 ##

<dependency>
                <groupId>com.github.wechatpay-apiv3</groupId>
                <artifactId>wechatpay-apache-httpclient</artifactId>
                <version>0.3.0</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
                <version>2.8.6</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpclient</artifactId>
                <version>4.5.12</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.google.zxing</groupId>
                <artifactId>core</artifactId>
                <version>3.3.3</version>
            </dependency>
            
            <dependency>
                <groupId>com.google.zxing</groupId>
                <artifactId>javase</artifactId>
                <version>3.3.3</version>
            </dependency>

## 四、配置文件添加微信支付所需参数 ##

# 微信支付相关参数
    wxpay:
      # 商户号
      mch-id: xxxxxxx
      # 商户API证书序列号
      mch-serial-no: xxxxxxxxxx
      # 商户私钥文件
      # 注意：该文件放在项目根目录下
      private-key-path: ./apiclient_key.pem
      # APIv3密钥
      api-v3-key: xxxxxxxx
      # APPID
      appid: xxxxxxc27e0e7cxxx
      # 微信服务器地址
      domain: https://api.mch.weixin.qq.com
      # 接收结果通知地址
      # 注意：每次重新启动ngrok，都需要根据实际情况修改这个配置
      notify-domain: https://c7c1-240e-3b5-3015-be0-1bc-9bed-fca4-d09b.ngrok.io

## 五、微信支付下单代码实现 ##

### 1.Controller层 ###

/**
         * native下单
         */
        @ApiOperation(value = "native 微信支付下单 返回Image")
        @GetMapping("/native")
        public BaseRes<String> nativePay(@RequestParam("packageId") Integer packageId) {
        
            return wxPayService.nativePay(packageId);
        }
    
      /**
         * JSAPI下单
         */
        @ApiOperation(value = "JSAPI微信支付下单")
        @GetMapping("/jsapi")
        public BaseRes<String> jsapiPay(@RequestParam("packageId") Integer packageId,@RequestParam("openId") String openId) {
        
            return wxPayService.jsapiPay(packageId,openId);
        }

注意：packageId是套餐Id，可根据情况修改

### 2.Service层 ###

BaseRes<String> nativePay(Integer packageId);
       
       BaseRes<String> jsapiPay(Integer packageId, String openId);

### 3.实现层 ###

/**
         * Mavicat下单
         * @return
         * @throws Exception
         */
        @Transactional(rollbackFor = Exception.class)
        @Override
        @SneakyThrows
        public BaseRes<String> nativePay(Integer packageId){
        
    
            log.info("发起Navicat支付请求");
    
            HttpPost httpPost = new HttpPost(wxPayConfig.getDomain().concat(WxApiType.NATIVE_PAY.getType()));
    
            CloseableHttpResponse response = wxPayExecute(packageId, null, httpPost);
    
            try {
        
                String bodyAsString = EntityUtils.toString(response.getEntity());//响应体
                int statusCode = response.getStatusLine().getStatusCode();//响应状态码
                if (statusCode == 200) {
         //处理成功
                    log.info("成功, 返回结果 = " + bodyAsString);
                } else if (statusCode == 204) {
         //处理成功，无返回Body
                    log.info("成功");
                } else {
        
                    log.info("Native下单失败,响应码 = " + statusCode + ",返回结果 = " + bodyAsString);
                    throw new IOException("request failed");
                }
    
                Gson gson = new Gson();
    
                //响应结果
                Map<String, String> resultMap = gson.fromJson(bodyAsString, HashMap.class);
                //二维码
                String codeUrl = resultMap.get("code_url");
    
                return new BaseRes<>(codeUrl,ServiceCode.SUCCESS);
    
                //生成二维码
    //            WxPayUtil.makeQRCode(codeUrl);
    
            } finally {
        
                response.close();
            }
        }
    
      /**
         * JSAPI下单
         * @return
         */
    
        @Override
        @SneakyThrows
        public BaseRes<String> jsapiPay(Integer packageId, String openId) {
        
    
            log.info("发起Navicat支付请求");
    
            HttpPost httpPost = new HttpPost(wxPayConfig.getDomain().concat(WxApiType.JSAPI_PAY.getType()));
    
            CloseableHttpResponse response = wxPayExecute(packageId, openId, httpPost);
    
            try {
        
                String bodyAsString = EntityUtils.toString(response.getEntity());//响应体
                int statusCode = response.getStatusLine().getStatusCode();//响应状态码
                if (statusCode == 200) {
         //处理成功
                    log.info("成功, 返回结果 = " + bodyAsString);
                } else if (statusCode == 204) {
         //处理成功，无返回Body
                    log.info("成功");
                } else {
        
                    log.info("JSAPI下单失败,响应码 = " + statusCode + ",返回结果 = " + bodyAsString);
                    throw new IOException("request failed");
                }
    
                Gson gson = new Gson();
    
                //响应结果
                Map<String, String> resultMap = gson.fromJson(bodyAsString, HashMap.class);
    
    
                String prepayId = resultMap.get("prepay_id");
    
                return new BaseRes<>(prepayId,ServiceCode.SUCCESS);
    
            } finally {
        
                response.close();
            }
        }
    
    
     // 封装统一下单方法	
      private CloseableHttpResponse wxPayExecute(Integer packageId,String openId,HttpPost httpPost) throws IOException {
        
    
            // 获取套餐金额 还有相关信息
            ChatPackage chatPackage = chatPackageMapper.selectById(packageId);
    
            if (null == chatPackage) {
        
                throw new NingException(ServiceCode.FAILED);
            }
    
            BigDecimal amount = chatPackage.getAmount();
    
            if (null == amount || amount.equals(BigDecimal.ZERO)) {
        
                throw new NingException(ServiceCode.SUCCESS);
            }
    		
    		// 从登录信息中获取用户信息
            TokenUser loginUserInfo = CommUtils.getLoginUserInfo();
            Integer userId = loginUserInfo.getUserId();
    
            // 请求body参数
            Gson gson = new Gson();
            Map<String,Object> paramsMap = new HashMap<>();
            paramsMap.put("appid", wxPayConfig.getAppid());
            paramsMap.put("mchid", wxPayConfig.getMchId());
            paramsMap.put("description", chatPackage.getName());
            paramsMap.put("out_trade_no", WxPayUtil.generateOrderNumber(userId,packageId)); //订单号
            paramsMap.put("notify_url", wxPayConfig.getNotifyDomain().concat(WxApiType.NATIVE_NOTIFY.getType()));
    
            Map<String,Object> amountMap = new HashMap<>();
            //由单位：元 转换为单位：分，并由Bigdecimal转换为整型
            BigDecimal total = amount.multiply(new BigDecimal(100));
    
            amountMap.put("total", total.intValue());
            amountMap.put("currency", "CNY");
    
            paramsMap.put("amount", amountMap);
    
    		// 判断是Navicat下单还是JSAPI下单 JSAPI需要传OPENID
            if (StringUtils.isNotBlank(openId)) {
        
                Map<String,Object> payerMap = new HashMap<>();
                payerMap.put("openid",openId);
                paramsMap.put("payer",payerMap);
            }
    
    
            JSONObject attachJson = new JSONObject();
            attachJson.put("packageId",packageId);
            attachJson.put("userId",userId);
            attachJson.put("total",total);
    
            paramsMap.put("attach",attachJson.toJSONString());
    
    
            //将参数转换成json字符串
            String jsonParams = gson.toJson(paramsMap);
            log.info("请求参数 ===> {}" , jsonParams);
    
            StringEntity entity = new StringEntity(jsonParams, "utf-8");
            entity.setContentType("application/json");
            httpPost.setEntity(entity);
            httpPost.setHeader("Accept", "application/json");
    
            //完成签名并执行请求
            return wxPayClient.execute(httpPost);
        }

## 六、微信支付回调接口 ##

### 1.Controller层 ###

/**
         * 支付通知
         * 微信支付通过支付通知接口将用户支付成功消息通知给商户
         */
        @ApiOperation(value = "支付通知", notes = "支付通知")
        @PostMapping("/pay/notify")
        @ClientAuthControl
        public WxRes nativeNotify() {
        
            return wxPayService.nativeNotify();
        }

### 2.Service层 ###

WxRes nativeNotify();

### 3.实现层 ###

@Resource
        private Verifier verifier;
        
        private final ReentrantLock lock = new ReentrantLock();
    
        @Override
        @SneakyThrows
        @Transactional
        public WxRes nativeNotify() {
        
            HttpServletRequest request = CommUtils.getRequest();
            HttpServletResponse response = CommUtils.getResponse();
    
            Gson gson = new Gson();
    
            try {
        
                //处理通知参数
                String body = WxPayUtil.readData(request);
                Map<String, Object> bodyMap = gson.fromJson(body, HashMap.class);
                String requestId = (String) bodyMap.get("id");
    
                //签名的验证
                WechatPay2ValidatorForRequest wechatPay2ValidatorForRequest
                        = new WechatPay2ValidatorForRequest(verifier, requestId, body);
                if (wechatPay2ValidatorForRequest.validate(request)) {
        
                    throw new RuntimeException();
                }
    
                log.info("通知验签成功");
    
                //处理订单
                processOrder(bodyMap);
    
                return new WxRes("SUCCESS","成功");
            } catch (Exception e) {
        
                e.printStackTrace();
    
                response.setStatus(500);
    
                return new WxRes("FAIL","成功");
            }
        }
    
       /**
         * 处理订单
         *
         * @param bodyMap
         */
        @Transactional
        @SneakyThrows
        public void processOrder(Map<String, Object> bodyMap){
        
            log.info("处理订单");
    
            //解密报文
            String plainText = decryptFromResource(bodyMap);
    
            //将明文转换成map
            Gson gson = new Gson();
            HashMap plainTextMap = gson.fromJson(plainText, HashMap.class);
            String orderNo = (String) plainTextMap.get("out_trade_no");
            String attach = (String) plainTextMap.get("attach");
            JSONObject attachJson = JSONObject.parseObject(attach);
            Integer packageId = attachJson.getInteger("packageId");
            Integer userId = attachJson.getInteger("userId");
            Integer total = attachJson.getInteger("total");
    
    
            /*在对业务数据进行状态检查和处理之前，
            要采用数据锁进行并发控制，
            以避免函数重入造成的数据混乱*/
            //尝试获取锁：
            // 成功获取则立即返回true，获取失败则立即返回false。不必一直等待锁的释放
            if (lock.tryLock()) {
        
                try {
        
    
                    log.info("plainText={}",plainText);
    
                    //处理重复的通知
                    //接口调用的幂等性：无论接口被调用多少次，产生的结果是一致的。
                    String orderStatus = orderService.getOrderStatus(orderNo);
                    if (!OrderStatus.NOTPAY.getType().equals(orderStatus)) {
        
                        return;
                    }
    
    				// TODO 修改订单状态、添加支付记录等
                  
    
    
                    // 通知前端用户 已完成支付
                    messageSocketHandle.sendMessageByUserID(userId,new TextMessage("PaySuccess"));
    
                } finally {
        
                    //要主动释放锁
                    lock.unlock();
                }
            }
        }
    
    	/**
         * 对称解密
         *
         * @param bodyMap
         * @return
         */
    
        @SneakyThrows
        private String decryptFromResource(Map<String, Object> bodyMap) {
        
    
            log.info("密文解密");
    
            //通知数据
            Map<String, String> resourceMap = (Map) bodyMap.get("resource");
            //数据密文
            String ciphertext = resourceMap.get("ciphertext");
            //随机串
            String nonce = resourceMap.get("nonce");
            //附加数据
            String associatedData = resourceMap.get("associated_data");
    
            AesUtil aesUtil = new AesUtil(wxPayConfig.getApiV3Key().getBytes(StandardCharsets.UTF_8));
            //数据明文
            String plainText = aesUtil.decryptToString(associatedData.getBytes(StandardCharsets.UTF_8),
                    nonce.getBytes(StandardCharsets.UTF_8),
                    ciphertext);
    
            return plainText;
        }

## 七、工具类和相关配置类 ##

### 1.WxPayUtil工具类 ###

@Slf4j
    public class WxPayUtil {
        
    
        private static final Random random = new Random();
    
    	// 生成订单号
        public static String generateOrderNumber(int userId, int packageId) {
        
            // 获取当前时间戳
            long timestamp = System.currentTimeMillis();
    
            // 生成6位随机数
            int randomNum = random.nextInt(900000) + 100000;
    
            // 组装订单号
            return String.format("%d%d%d%d", timestamp, randomNum, userId, packageId);
        }
    
    
        /**
         * 生成二维码
         * @param url
         */
        public static void makeQRCode(String url){
        
    
            HttpServletResponse response = CommUtils.getResponse();
    
            //通过支付链接生成二维码
            HashMap<EncodeHintType, Object> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
            hints.put(EncodeHintType.MARGIN, 2);
            try {
        
                BitMatrix bitMatrix = new MultiFormatWriter().encode(url, BarcodeFormat.QR_CODE, 200, 200, hints);
                MatrixToImageWriter.writeToStream(bitMatrix, "PNG", response.getOutputStream());
                System.out.println("创建二维码完成");
            } catch (Exception e) {
        
                e.printStackTrace();
            }
        }
    
    
        /**
         * 将通知参数转化为字符串
         *
         * @param request
         * @return
         */
        public static String readData(HttpServletRequest request) {
        
            BufferedReader br = null;
            try {
        
                StringBuilder result = new StringBuilder();
                br = request.getReader();
                for (String line; (line = br.readLine()) != null; ) {
        
                    if (result.length() > 0) {
        
                        result.append("\n");
                    }
                    result.append(line);
                }
                return result.toString();
            } catch (IOException e) {
        
                throw new RuntimeException(e);
            } finally {
        
                if (br != null) {
        
                    try {
        
                        br.close();
                    } catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
            }
        }
    }

### 2.微信支付配置类 ###

@Configuration
    @ConfigurationProperties(prefix = "wxpay") //读取wxpay节点
    @Data //使用set方法将wxpay节点中的值填充到当前类的属性中
    @Slf4j
    public class WxPayConfig {
        
    
        // 商户号
        private String mchId;
    
        // 商户API证书序列号
        private String mchSerialNo;
    
        // 商户私钥文件
        private String privateKeyPath;
    
        // APIv3密钥
        private String apiV3Key;
    
        // APPID
        private String appid;
    
        // 微信服务器地址
        private String domain;
    
        // 接收结果通知地址
        private String notifyDomain;
    
        /**
         * 获取商户的私钥文件
         *
         * @param filename
         * @return
         */
        private PrivateKey getPrivateKey(String filename) {
        
    
            try {
        
                return PemUtil.loadPrivateKey(new FileInputStream(filename));
            } catch (FileNotFoundException e) {
        
                throw new RuntimeException("私钥文件不存在", e);
            }
        }
    
        /**
         * 获取签名验证器
         *
         * @return
         */
        @Bean
        public ScheduledUpdateCertificatesVerifier getVerifier() {
        
    
            log.info("获取签名验证器");
    
            //获取商户私钥
            PrivateKey privateKey = getPrivateKey(privateKeyPath);
    
            //私钥签名对象
            PrivateKeySigner privateKeySigner = new PrivateKeySigner(mchSerialNo, privateKey);
    
            //身份认证对象
            WechatPay2Credentials wechatPay2Credentials = new WechatPay2Credentials(mchId, privateKeySigner);
    
            // 使用定时更新的签名验证器，不需要传入证书
            ScheduledUpdateCertificatesVerifier verifier = new ScheduledUpdateCertificatesVerifier(
                    wechatPay2Credentials,
                    apiV3Key.getBytes(StandardCharsets.UTF_8));
    
            return verifier;
        }
    
    
        /**
         * 获取http请求对象
         *
         * @param verifier
         * @return
         */
        @Bean(name = "wxPayClient")
        public CloseableHttpClient getWxPayClient(ScheduledUpdateCertificatesVerifier verifier) {
        
    
            log.info("获取httpClient");
    
            //获取商户私钥
            PrivateKey privateKey = getPrivateKey(privateKeyPath);
    
            WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create()
                    .withMerchant(mchId, mchSerialNo, privateKey)
                    .withValidator(new WechatPay2Validator(verifier));
            // ... 接下来，你仍然可以通过builder设置各种参数，来配置你的HttpClient
    
            // 通过WechatPayHttpClientBuilder构造的HttpClient，会自动的处理签名和验签，并进行证书自动更新
            CloseableHttpClient httpClient = builder.build();
    
            return httpClient;
        }
    
        /**
         * 获取HttpClient，无需进行应答签名验证，跳过验签的流程
         */
        @Bean(name = "wxPayNoSignClient")
        public CloseableHttpClient getWxPayNoSignClient() {
        
    
            //获取商户私钥
            PrivateKey privateKey = getPrivateKey(privateKeyPath);
    
            //用于构造HttpClient
            WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create()
                    //设置商户信息
                    .withMerchant(mchId, mchSerialNo, privateKey)
                    //无需进行签名验证、通过withValidator((response) -> true)实现
                    .withValidator((response) -> true);
    
            // 通过WechatPayHttpClientBuilder构造的HttpClient，会自动的处理签名和验签，并进行证书自动更新
            CloseableHttpClient httpClient = builder.build();
    
            log.info("== getWxPayNoSignClient END ==");
    
            return httpClient;
        }
    
    }

### 3.微信支付枚举类 ###

@AllArgsConstructor
    @Getter
    public enum WxApiType {
        
    
        /**
         * Native下单
         */
        NATIVE_PAY("/v3/pay/transactions/native"),
    
        /**
         * JSAPI下单
         */
        JSAPI_PAY("/v3/pay/transactions/jsapi"),
    
        /**
         * 查询订单
         */
        ORDER_QUERY_BY_NO("/v3/pay/transactions/out-trade-no/%s"),
    
        /**
         * 关闭订单
         */
        CLOSE_ORDER_BY_NO("/v3/pay/transactions/out-trade-no/%s/close"),
    
        /**
         * 支付通知
         */
        NATIVE_NOTIFY("/client/order/pay/notify");
    
        /**
         * 类型
         */
        private final String type;
    }

### 4.签名验证类 ###

@Slf4j
    public class WechatPay2ValidatorForRequest {
        
        /**
         * 应答超时时间，单位为分钟
         */
        protected static final long RESPONSE_EXPIRED_MINUTES = 5;
        protected final Verifier verifier;
        protected final String requestId;
        protected final String body;
    
    
        public WechatPay2ValidatorForRequest(Verifier verifier, String requestId, String body) {
        
            this.verifier = verifier;
            this.requestId = requestId;
            this.body = body;
        }
    
        protected static IllegalArgumentException parameterError(String message, Object... args) {
        
            message = String.format(message, args);
            return new IllegalArgumentException("parameter error: " + message);
        }
    
        protected static IllegalArgumentException verifyFail(String message, Object... args) {
        
            message = String.format(message, args);
            return new IllegalArgumentException("signature verify fail: " + message);
        }
    
        public final boolean validate(HttpServletRequest request) throws IOException {
        
            try {
        
                //处理请求参数
                validateParameters(request);
    
                //构造验签名串
                String message = buildMessage(request);
    
                String serial = request.getHeader(WECHAT_PAY_SERIAL);
                String signature = request.getHeader(WECHAT_PAY_SIGNATURE);
    
                //验签
                if (!verifier.verify(serial, message.getBytes(StandardCharsets.UTF_8), signature)) {
        
                    throw verifyFail("serial=[%s] message=[%s] sign=[%s], request-id=[%s]",
                            serial, message, signature, requestId);
                }
            } catch (IllegalArgumentException e) {
        
                log.error(e.getMessage());
                return false;
            }
    
            return true;
        }
    
        protected final void validateParameters(HttpServletRequest request) {
        
    
            // NOTE: ensure HEADER_WECHAT_PAY_TIMESTAMP at last
            String[] headers = {
        WECHAT_PAY_SERIAL, WECHAT_PAY_SIGNATURE, WECHAT_PAY_NONCE, WECHAT_PAY_TIMESTAMP};
    
            String header = null;
            for (String headerName : headers) {
        
                header = request.getHeader(headerName);
                if (header == null) {
        
                    throw parameterError("empty [%s], request-id=[%s]", headerName, requestId);
                }
            }
    
            //判断请求是否过期
            String timestampStr = header;
            try {
        
                Instant responseTime = Instant.ofEpochSecond(Long.parseLong(timestampStr));
                // 拒绝过期请求
                if (Duration.between(responseTime, Instant.now()).abs().toMinutes() >= RESPONSE_EXPIRED_MINUTES) {
        
                    throw parameterError("timestamp=[%s] expires, request-id=[%s]", timestampStr, requestId);
                }
            } catch (DateTimeException | NumberFormatException e) {
        
                throw parameterError("invalid timestamp=[%s], request-id=[%s]", timestampStr, requestId);
            }
        }
    
        protected final String buildMessage(HttpServletRequest request) throws IOException {
        
            String timestamp = request.getHeader(WECHAT_PAY_TIMESTAMP);
            String nonce = request.getHeader(WECHAT_PAY_NONCE);
            return timestamp + "\n"
                    + nonce + "\n"
                    + body + "\n";
        }
    
        protected final String getResponseBody(CloseableHttpResponse response) throws IOException {
        
            HttpEntity entity = response.getEntity();
            return (entity != null && entity.isRepeatable()) ? EntityUtils.toString(entity) : "";
        }
    
    }

OK，齐活~

[ae7c841c56f04b4c986cc3668e10b0c4.png]: https://img-blog.csdnimg.cn/ae7c841c56f04b4c986cc3668e10b0c4.png