微信小程序-微信支付和微信退款（Java后台）

微信支付流程

都是我自己工作中开发的，亲测可用，不喜勿喷。

• controller中我是这么写的，你们需要根据自己的业务需求改动。ResponseBean是我自己封装的，你们可以改成你们想要的形式。`

 /**
     * 微信统一下单接口
     * @return
     */
    @RequestMapping(value = "/doUnifiedOrder", method = RequestMethod.POST)
    public ResponseBean doUnifiedOrder(@RequestBody Map<String,Object> req) {
        Map resultMap=new HashMap();
        String openid = (String) req.get("openId");

        WXPay wxpay =null;

        try {
            //初始化证书
            myConfig.initCert();
            wxpay= new WXPay(myConfig);
        } catch (Exception e) {
            e.printStackTrace();
        }
        //生成的随机字符串
        String nonce_str = WXPayUtil.generateNonceStr();
        //获取客户端的ip地址
        //获取本机的ip地址
        InetAddress addr = null;
        try {
            addr = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        //支付金额，需要转成字符串类型，否则后面的签名会失败
        String payOutMoney = WxMoney.changeY2F(String.valueOf(req.get("money")));
        String tradeName = (String) req.get("tradeName");
        if(tradeName!=null&&tradeName.length()>0){

        }else{
            tradeName = "课程支付";
        }
        String body = tradeName;
        //商户订单号
        String out_trade_no= WXPayUtil.generateNonceStr();
        //统一下单接口参数
        HashMap<String, String> data = new HashMap<String, String>();
        data.put("appid", 你的appid);
        data.put("mch_id", 商户id);
        data.put("nonce_str", nonce_str);
        data.put("body", body);
        data.put("out_trade_no",out_trade_no);
        data.put("total_fee", payOutMoney);
        data.put("spbill_create_ip", "127.0.0.1");
        data.put("notify_url", 回调地址);
        data.put("trade_type","JSAPI");
        data.put("openid", openid);
        try {
            Map<String, String> rMap = wxpay.unifiedOrder(data);
            String return_code = (String) rMap.get("return_code");
            String result_code = (String) rMap.get("result_code");
            String nonceStr = WXPayUtil.generateNonceStr();
            resultMap.put("nonceStr", nonceStr);
            Long timeStamp = System.currentTimeMillis() / 1000;
            if ("SUCCESS".equals(return_code) && return_code.equals(result_code)) {
                    String prepayid = rMap.get("prepay_id");
                    resultMap.put("package", "prepay_id="+prepayid);
                    resultMap.put("signType", "MD5");
                    //这边要将返回的时间戳转化成字符串，不然小程序端调用wx.requestPayment方法会报签名错误
                    resultMap.put("timeStamp", timeStamp + "");
                    //再次签名，这个签名用于小程序端调用wx.requesetPayment方法
                    resultMap.put("appId",myConfig.getAppID());
                    String sign = WXPayUtil.generateSignature(resultMap, myConfig.getKey());
                    resultMap.put("paySign", sign);
                    resultMap.put("out_trade_no",out_trade_no);
                    ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信支付",resultMap);
                    return responseBean;

            }else{
                ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信支付失败","微信支付失败");
                return  responseBean;
            }
        } catch (Exception e) {
            ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信支付失败","微信支付失败");
            e.printStackTrace();
            return  responseBean;
        }
    }

微信退款代码（需要传退款的订单id）

    public ResponseBean refund(Map<String, Object> req) {
        Map resultMap=new HashMap();
        String buyId = (String) req.get("buyId");
        WXPay wxpay =null;
        try {
            myConfig.initCert();//初始化证书
            wxpay= new WXPay(myConfig);
        } catch (Exception e) {
            e.printStackTrace();
        }
        //生成的随机字符串
        String nonce_str = WXPayUtil.generateNonceStr();
        //获取客户端的ip地址
        //获取本机的ip地址
        InetAddress addr = null;
        try {
            addr = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        //支付金额，需要转成字符串类型，否则后面的签名会失败
//        int  total_fee= (int) req.get("money");
        String payOutMoney = WxMoney.changeY2F(String.valueOf(req.get("money")));

//        String body = (String) req.get("z");
        //商户订单号
        String out_trade_no= WXPayUtil.generateNonceStr();
        //统一下单接口参数
        HashMap<String, String> data = new HashMap<String, String>();

        try {
            data.put("appid", myConfig.getAppID());
            data.put("mch_id", myConfig.getMchID());
            data.put("nonce_str", nonce_str);
            data.put("sign_type", "MD5");
            data.put("out_trade_no",buyId);//微信订单号
            data.put("out_refund_no", out_trade_no);//商户退款单号
            data.put("total_fee",payOutMoney);//支付金额，微信支付提交的金额是不能带小数点的，且是以分为单位,这边需要转成字符串类型，否则后面的签名会失败
            data.put("refund_fee",payOutMoney);//退款总金额,订单总金额,单位为分,只能为整数
            //MD5运算生成签名，这里是第一次签名，用于调用统一下单接口
            String sign = WXPayUtil.generateSignature(data, myConfig.getKey());
            data.put("sign", sign);

            Map<String, String> rMap = wxpay.refund(data);
            String return_code = (String) rMap.get("return_code");
            String result_code = (String) rMap.get("result_code");

            Long timeStamp = System.currentTimeMillis() / 1000;
            if ("SUCCESS".equals(return_code) && return_code.equals(result_code)) {

                ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信退款成功",rMap);
                return responseBean;

            }else{
                ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信退款失败","微信支付失败");
                return  responseBean;
            }


        } catch (Exception e) {
            ResponseBean responseBean = new ResponseBean(HttpStatus.OK.value(),"微信退款失败","微信支付失败");
            e.printStackTrace();
            return  responseBean;
        }
    }

需要用到的工具类

然后在MyConfig中配置一下你们的小程序参数就行了，如果需要添加退款功能必须配置商户证书（对应在你项目中的位置）。不需要的话就把initCert方法去掉。

public class MyConfig extends WXPayConfig {
    @Value("${res.imgPath}")
    public String imgPath;

    private byte[] certData;


    @Override
    public String getAppID() {
        return "你的小程序id";
    }

    @Override
    public String getMchID() {
        return "商户id";
    }

    @Override
    public String getKey() {
        return "商户秘钥";
    }

    @Override
    public InputStream getCertStream() {
        ByteArrayInputStream certBis = new ByteArrayInputStream(this.certData);
        return certBis;
    }

    @Override
    public int getHttpConnectTimeoutMs() {
        return 8000;
    }

    @Override
    public int getHttpReadTimeoutMs() {
        return 10000;
    }

    @Override
    IWXPayDomain getWXPayDomain() {
        return new IWXPayDomain() {
            @Override
            public void report(String domain, long elapsedTimeMillis, Exception ex) {
            }

            @Override
            public DomainInfo getDomain(WXPayConfig config) {
                return new DomainInfo("api.mch.weixin.qq.com", false);
            }
        };
    }
    
    @Override
    public void initCert() throws Exception {
        String certPath = this.imgPath+"/upload/cert/"+"apiclient_cert.p12";//从微信商户平台下载的安全证书存放的目录
        System.out.println(certPath);
        File file = new File(certPath);
        InputStream certStream = new FileInputStream(file);
        this.certData = new byte[(int) file.length()];
        certStream.read(this.certData);
        certStream.close();
    }
}

关注公众号回复微信支付获取工具类文件。