java-spring boot项目之微信支付功能实现（微信公众号支付）

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最近在做微信公众号支付，看文档做的，感觉踩了不少坑，为了避免后人采坑，所以写下此文档

1：前往微信公众号商户平台，拿到要做支付必要的各种id和密钥。

2：引入微信sdk，在项目中的pom文件中加入下面的依赖（或者直接将下载的sdk demo放入项目）

  <dependency>
  <groupId>com.github.wxpay</groupId>
  <artifactId>wxpay-sdk</artifactId>
  <version>0.0.3</version>
  </dependency>

3：域名管理，实现主备域名自动切换实现类

public class WXPayDomainSimpleImpl implements IWXPayDomain {
    private WXPayDomainSimpleImpl(){}
    private static class WxpayDomainHolder{
        private static IWXPayDomain holder = new WXPayDomainSimpleImpl();
    }
    public static IWXPayDomain instance(){
        return WxpayDomainHolder.holder;
    }

    public synchronized void report(final String domain, long elapsedTimeMillis, final Exception ex) {
        DomainStatics info = domainData.get(domain);
        if(info == null){
            info = new DomainStatics(domain);
            domainData.put(domain, info);
        }

        if(ex == null){ //success
            if(info.succCount >= 2){    //continue succ, clear error count
                info.connectTimeoutCount = info.dnsErrorCount = info.otherErrorCount = 0;
            }else{
                ++info.succCount;
            }
        }else if(ex instanceof ConnectTimeoutException){
            info.succCount = info.dnsErrorCount = 0;
            ++info.connectTimeoutCount;
        }else if(ex instanceof UnknownHostException){
            info.succCount = 0;
            ++info.dnsErrorCount;
        }else{
            info.succCount = 0;
            ++info.otherErrorCount;
        }
    }

    public synchronized DomainInfo getDomain(final WXPayConfig config) {
        DomainStatics primaryDomain = domainData.get(WXPayConstants.DOMAIN_API);
        if(primaryDomain == null ||
                primaryDomain.isGood()) {
            return new DomainInfo(WXPayConstants.DOMAIN_API, true);
        }

        long now = System.currentTimeMillis();
        if(switchToAlternateDomainTime == 0){   //first switch
            switchToAlternateDomainTime = now;
            return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
        }else if(now - switchToAlternateDomainTime < MIN_SWITCH_PRIMARY_MSEC){
            DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
            if(alternateDomain == null ||
                    alternateDomain.isGood() ||
                    alternateDomain.badCount() < primaryDomain.badCount()){
                return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
            }else{
                return new DomainInfo(WXPayConstants.DOMAIN_API, true);
            }
        }else{  //force switch back
            switchToAlternateDomainTime = 0;
            primaryDomain.resetCount();
            DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
            if(alternateDomain != null)
                alternateDomain.resetCount();
            return new DomainInfo(WXPayConstants.DOMAIN_API, true);
        }
    }

    static class DomainStatics {
        final String domain;
        int succCount = 0;
        int connectTimeoutCount = 0;
        int dnsErrorCount =0;
        int otherErrorCount = 0;

        DomainStatics(String domain) {
            this.domain = domain;
        }
        void resetCount(){
            succCount = connectTimeoutCount = dnsErrorCount = otherErrorCount = 0;
        }
        boolean isGood(){ return connectTimeoutCount <= 2 && dnsErrorCount <= 2; }
        int badCount(){
            return connectTimeoutCount + dnsErrorCount * 5 + otherErrorCount / 4;
        }
    }
    private final int MIN_SWITCH_PRIMARY_MSEC = 3 * 60 * 1000;  //3 minutes
    private long switchToAlternateDomainTime = 0;
    private Map<String, DomainStatics> domainData = new HashMap<String, DomainStatics>();
}

4：配置代码如下

public class JSAPIConfig extends WXPayConfig {
    private byte[] certData;

    public JSAPIConfig() throws Exception {
       //引入证书路径
        File file = ResourceUtils.getFile(""填写你的证书路径");
        InputStream certStream = new FileInputStream(file);
        this.certData = new byte[(int) file.length()];
        certStream.read(this.certData);
        certStream.close();
    }

    public String getAppID() {
        return "填写你的AppID";
    }

    public String getMchID() {
        return "填写你的getMchID";
    }

    public String getKey() {
        return "填写你的getKey";
    }

    public InputStream getCertStream() {
        ByteArrayInputStream certBis = new ByteArrayInputStream(this.certData);
        return certBis;
    }
   public IWXPayDomain getWXPayDomain() {
        return WXPayDomainSimpleImpl.instance();
    }

    public String getPrimaryDomain() {
        return "api.mch.weixin.qq.com";
    }
    public int getHttpConnectTimeoutMs() {
        return 80000;
    }

    public int getHttpReadTimeoutMs() {
        return 100000;
    }
}

4：服务器端生成签名后的订单信息返回给前端的controller代码：

     

 @Login
 @RequestMapping("UnifiedOrder")
 @ApiOperation("公众号用户充值")
 public R UnifiedOrder(@ApiIgnore @RequestAttribute("userId") Integer userId, @RequestBody Map<String,Object> params, HttpSession httpSession,HttpServletRequest httpServletRequest) throws Exception {
        String trxamt = (String) params.get("trxamt");//充值金额 单位：元
        String amount = Tools.yuanToCent(trxamt);//将元转为分
        String body = (String) params.get("body");//支付信息 如购买流量-微信充值
        String openid = (String) httpSession.getAttribute("openid");//获取用户openid
        openid = (openid == null || "".equals(openid)) ? (String) params.get("openid") : openid;
        if (openid == null || "".equals(openid)) {
            return R.error("opend获取失败");
        }
        //生成订单号
        String orderId = System.currentTimeMillis() + "js" + userId;
        Map<String, String> data = new HashMap<String, String>();
        data.put("body", body);//支付信息
        data.put("out_trade_no", orderId); //订单号
        data.put("device_info", "WEB");//设备信息
        data.put("fee_type", "CNY");//币种
        data.put("total_fee", amount);//充值金额
        data.put("spbill_create_ip", "127.0.0.14");//客户端IP
        data.put("notify_url","127.0.0.14:8082/api/notify");//异步回调通知地址
        data.put("trade_type", "JSAPI");  // 此处指定为扫码支付
        data.put("openid", openid);//用户openid
        Map res=wxPayService.dounifiedOrder(data,userId);//调取服务层统一下单
        if (res.get("code").equals("1")){
            logger.error(res.get("msg").toString());
            return R.error();
        }
        return R.ok().put("data",res);
    }

5:service中的下单方法

  @Override
    @Transactional
    public  Map<String, String> dounifiedOrder(Map<String, String> data, Integer userId){
        Map<String, String> fail = new HashMap<>();
        fail.put("code","1");
        try {
            JSAPIConfig config = new JSAPIConfig();
            WXPay wxpay = new WXPay(config);
            Map<String, String> map = wxpay.unifiedOrder(data);
            System.out.println(map);
            if (map == null) {
                throw new Exception("返回数据错误");
            }
            if ("SUCCESS".equals(map.get("return_code"))) {
                if ("SUCCESS".equals(map.get("result_code"))) {
                   //此处为下单成功关于订单处理代码
                   //订单入库
                   //创建支付信息
                    Map<String, String> resault = new HashMap<String, String>();
                    Long timeStamp=WXPayUtil.getCurrentTimestamp();
                    String prepay_id="prepay_id="+map.get("prepay_id");
                    String nonceStr =WXPayUtil.generateNonceStr();
                    resault.put("appId",WXConfig.getAppID());
                    resault.put("timeStamp",timeStamp.toString());
                    resault.put("nonceStr",nonceStr);
                    resault.put("package",prepay_id);
                    resault.put("signType","MD5");
                    String sign=WXPayUtil.generateSignature(resault, WXConfig.getKey());
                    resault.put("paySign",sign);
                    resault.put("code","0");
                    return resault;
                } else {
                    throw new Exception("下单失败");
                }
            } else {
                throw new Exception(map.get("return_msg").toString());
            }
        } catch (Exception e) {
            e.printStackTrace();
            fail.put("msg",e.getMessage());
            return fail;
        }
    }

6:服务器端支付成功异步回调通知处理方法的controller代码：

   

扫描二维码关注公众号，回复： 5488421 查看本文章

   @RequestMapping("JSPayNotify")
    @ApiOperation("微信公众号结果通知")
    @Transactional
    public String JSPayNotify(HttpServletRequest request , HttpServletResponse response) throws UnsupportedEncodingException {
        System.out.println("接收到通知");
        String notifyData = "";// 支付结果通知的xml格式数据
        try {
            InputStream is = request.getInputStream();
            //将InputStream转换成String
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            String line = null;
            try {
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");                          }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            notifyData=sb.toString();
            System.err.println(notifyData);
            String resault=wxPayService.notify(notifyData);
            return resault;
        }catch (Exception e){
            logger.info("支付回到处理异常");
            logger.error(notifyData.toString());
            logger.error(e.getMessage());
            return "<xml><return_code><![CDATA[FAIL]]></return_code> <return_msg><![CDATA[报文为空]]></return_msg></xml> ";
        }
    }

7:服务器端支付成功异步回调通知处理方法的service代码：

 /**
     *  支付结果通知
     * @param notifyData    异步通知后的XML数据
     * @return
     */
    @Override
    @Transactional
    public String notify(String notifyData){
        try{
            JSAPIConfig config = new JSAPIConfig();
            WXPay wxpay = new WXPay(config);
            Map<String, String> notifyMap = WXPayUtil.xmlToMap(notifyData);  // 转换成map
            if (notifyMap == null) {
                throw new Exception("返回数据错误");
            }
            if ("SUCCESS".equals(notifyMap.get("return_code"))) {
                if("SUCCESS".equals(notifyMap.get("result_code"))){
                    if (wxpay.isPayResultNotifySignatureValid(notifyMap)) {
                        // 签名正确
                        // 进行处理。
                        // 注意特殊情况：订单已经退款，但收到了支付结果成功的通知，不应把商户侧订单状态从退款改成支付成功
                   
                            return "<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[报文为空]]></return_msg></xml> ";
                            }
                        }
                    } else {
                        // 签名错误，如果数据里没有sign字段，也认为是签名错误
                        throw  new Exception("签名错误");
                    }
                } else {
                    throw  new Exception("下单失败");
                }
            } else {
                throw new Exception(notifyMap.get("err_code_des"));
            }
        }catch (Exception e){
            return "<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[报文为空]]></return_msg></xml> ";
        }
    }

注：微信公众号支付签名验证错误

最新微信支付提供的SDK代码中，统一下单接口sign_type是置为 HMAC-SHA256 而不是使用默认的 MD5，而公众号内发起支付的签名只能使用 MD5，正是这种不一致导致了签名验证错误，将统一下单的签名类型改成MD5即可。