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Java实现微信支付

一、业务需求

实现app微信支付，后端需要做生成预支付单，响应支付结果。

二、业务流程

查看官方文档

https://pay.weixin.qq.com/wik... ；

三、实现方法

3.1 创建微信工具类 ConstantUtil

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public class ConstantUtil {

/**
 * 微信开发平台应用ID
 */
public static final String APP_ID="wx2421b1c4370ec43b";
/**
 * 应用对应的凭证
 */
public static final String APP_SECRET="1add1a30ac87aa2db72f57a2375d8fec";
/**
 * 应用对应的密钥
 */
public static final String APP_KEY="1add1a30ac87aa2db72f57a2375d8fec";
/**
 * 微信支付商户号
 */
public static final String MCH_ID="10000100";
/**
 * 商品描述
 */
public static final String BODY="充值";
/**
 * 商户号对应的密钥
 */
public static final String PARTNER_key="*******"; 

/**
 * 商户id
 */
public static final String PARTNER_ID="*******"; 
/**
 * 常量固定值
 */
public static final String GRANT_TYPE="client_credential";
/**
 * 获取预支付id的接口url
 */
public static String GATEURL = "https://api.mch.weixin.qq.com/pay/unifiedorder";
/**
 * 微信服务器回调通知url
 */
public static String NOTIFY_URL="http://url"; //可以访问的url
/**
 * 微信服务器查询订单url
 */
public static String ORDER_QUERY="https://api.mch.weixin.qq.com/pay/orderquery";

}

3.2 生成预支付订单

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Map<String, Object> getOrder(@RequestParam(value = "totalFee") String totalFee, @RequestParam(value = "deviceInfo") String deviceInfo,

@RequestParam(value = "attach") String attach,
                             HttpServletRequest request, HttpServletResponse response)
        throws Exception {
    Map<String, Object> map = new HashMap<String, Object>();
    // 获取生成预支付订单的请求类
    PrepayIdRequestHandler prepayReqHandler = new PrepayIdRequestHandler(request, response);

// String totalFee = request.getParameter("total_fee");

int total_fee = (int) (Float.valueOf(totalFee) * 100);
    System.out.println("total:" + total_fee);
    System.out.println("total_fee:" + total_fee);
    prepayReqHandler.setParameter("appid", ConstantUtil.APP_ID);
    prepayReqHandler.setParameter("body", ConstantUtil.BODY);
    prepayReqHandler.setParameter("mch_id", ConstantUtil.MCH_ID);
    prepayReqHandler.setParameter("device_info", deviceInfo); //卡号
    prepayReqHandler.setParameter("attach", attach);//套餐值
    String nonce_str = WXUtil.getNonceStr();
    prepayReqHandler.setParameter("nonce_str", nonce_str);
    prepayReqHandler.setParameter("notify_url", ConstantUtil.NOTIFY_URL);
    out_trade_no = String.valueOf(UUID.next());
    prepayReqHandler.setParameter("out_trade_no", out_trade_no);
    prepayReqHandler.setParameter("spbill_create_ip", request.getRemoteAddr());
    String timestamp = WXUtil.getTimeStamp();
    prepayReqHandler.setParameter("time_start", timestamp);
    System.out.println(String.valueOf(total_fee));
    prepayReqHandler.setParameter("total_fee", String.valueOf(total_fee));
    prepayReqHandler.setParameter("trade_type", "APP");
    /**
     * 注意签名（sign）的生成方式，具体见官方文档（传参都要参与生成签名，且参数名按照字典序排序，最后接上APP_KEY,转化成大写）
     */
    prepayReqHandler.setParameter("sign", prepayReqHandler.createMD5Sign());
    prepayReqHandler.setGateUrl(ConstantUtil.GATEURL);
    String prepayid = prepayReqHandler.sendPrepay();
    // 若获取prepayid成功，将相关信息返回客户端
    if (prepayid != null && !prepayid.equals("")) {
        String signs = "appid=" + ConstantUtil.APP_ID + "&noncestr=" + nonce_str + "&package=Sign=WXPay&partnerid="
                + ConstantUtil.PARTNER_ID + "&prepayid=" + prepayid + "×tamp=" + timestamp + "&key="
                + ConstantUtil.APP_KEY;
        map.put("code", 0);
        map.put("info", "success");
        map.put("prepayid", prepayid);
        /**
         * 签名方式与上面类似
         */
        map.put("sign", MD5Util.MD5Encode(signs, "utf8").toUpperCase());
        map.put("appid", ConstantUtil.APP_ID);
        map.put("device_info", deviceInfo);
        map.put("attach", attach);
        map.put("timestamp", timestamp);  //等于请求prepayId时的time_start
        map.put("noncestr", nonce_str);   //与请求prepayId时值一致
        map.put("package", "Sign=WXPay");  //固定常量
        map.put("partnerid", ConstantUtil.PARTNER_ID);
    } else {
        map.put("code", 1);
        map.put("info", "获取prepayid失败");
    }
    return map;
}

3.3 异步通知客户结果

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PrintWriter writer = response.getWriter();

InputStream inStream = request.getInputStream();
    ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int len = 0;
    while ((len = inStream.read(buffer)) != -1) {
        outSteam.write(buffer, 0, len);
    }
    outSteam.close();
    inStream.close();
    String result = new String(outSteam.toByteArray(), "utf-8");
    System.out.println("微信支付通知结果：" + result);
    Map<String, String> map = null;
    try {
        /**
         * 解析微信通知返回的信息
         */
        map = XMLUtil.doXMLParse(result);
    } catch (JDOMException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

官方文档中特别提醒：商户系统对于支付结果通知的内容一定要做签名验证,并校验返回的订单金额是否与商户侧的订单金额一致，防止数据泄漏导致出现“假通知”，造成资金损失。

支付结果通知内容做签名验证。

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//支付成功后sign校验

String appid=map.get("appid");

String transaction_id=map.get("transaction_id");

String nonce_str =map.get("nonce_str");

String bank_type =map.get("bank_type");

String openid=map.get("openid");

String sign =map.get("sign");

String fee_type =map.get("fee_type");

String mch_id =map.get("mch_id");

String cash_fee =map.get("cash_fee");

String device_info =map.get("device_info");

String out_trade_no =map.get("out_trade_no");

String total_fee =map.get("total_fee");

String trade_type =map.get("trade_type");

String result_code =map.get("result_code");

String attach =map.get("attach");

String time_end =map.get("time_end");

String is_subscribe =map.get("is_subscribe");

String return_code=map.get("return_code");

PrepayIdRequestHandler prepayReqHandler = new PrepayIdRequestHandler(request, response);

prepayReqHandler.setParameter("appid",appid);

prepayReqHandler.setParameter("attach",attach);

prepayReqHandler.setParameter("bank_type",bank_type);

prepayReqHandler.setParameter("cash_fee",cash_fee);

prepayReqHandler.setParameter("device_info",device_info);

prepayReqHandler.setParameter("fee_type",fee_type);

prepayReqHandler.setParameter("is_subscribe",is_subscribe);

prepayReqHandler.setParameter("mch_id",mch_id);

prepayReqHandler.setParameter("nonce_str",nonce_str);

prepayReqHandler.setParameter("openid",openid);

prepayReqHandler.setParameter("out_trade_no",out_trade_no);

prepayReqHandler.setParameter("result_code",result_code);

prepayReqHandler.setParameter("return_code",return_code);

prepayReqHandler.setParameter("time_end",time_end);

prepayReqHandler.setParameter("total_fee",total_fee);

prepayReqHandler.setParameter("trade_type",trade_type);

prepayReqHandler.setParameter("transaction_id",transaction_id);

String endSigns =prepayReqHandler.createMD5Sign(); //支付结果通知的内容签名校验

商户金额的查询

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PrepayIdRequestHandler orderQueryHandler = new PrepayIdRequestHandler(request, response);

orderQueryHandler.setParameter("appid",appid);
    orderQueryHandler.setParameter("mch_id",mch_id);
    orderQueryHandler.setParameter("out_trade_no",out_trade_no);
    orderQueryHandler.setParameter("nonce_str",nonce_str);
    orderQueryHandler.setParameter("sign",orderQueryHandler.createMD5Sign());
    orderQueryHandler.setGateUrl(ConstantUtil.ORDER_QUERY);
    String resXml = "";
    WeixinOrderBean orderBean =orderQueryHandler.selectOrder();

应答微信

[AppleScript] 纯文本查看复制代码

if(sign.equals(endSigns) && Integer.parseInt(total_fee)==orderBean.getTotal_fee()){ // 签名通过并且返回的订单的金额与商户金额相同

// 若支付成功，则告知微信服务器收到通知
        if (map.get("return_code").equals("SUCCESS")) {
            System.out.println("充值成功！");
            //PayRecord payRecord=payRecordService.get(Long.valueOf(map.get("out_trade_no")));
            System.out.println("订单号：" + Long.valueOf(map.get("out_trade_no")));
            String iccids = map.get("device_info");
            String monthNum = map.get("attach");

//根据自己的业务处理

int count =trafficCardListService.selectExistTrafficCardByOutTradeNo(map.get("out_trade_no")); //查询商户订单号是否存在
            if(count==0){//不存在就插入
                List<MsisdnOrderBean> msisdnOrderList = trafficCardListService.selectTrafficCardRechargeResult(iccids, monthNum);
                if (msisdnOrderList.size() > 0) {
                    for (MsisdnOrderBean msisdnOrderBean : msisdnOrderList) {
                        msisdnOrderBean.setOutTradeNo(map.get("out_trade_no"));
                        msisdnOrderBean.setDate(map.get("time_end"));
                        msisdnOrderBean.setIccids(map.get("device_info"));
                        // msisdnOrderBean.setTotalFee(Integer.parseInt(map.get("total_fee")));
                        msisdnOrderBean.setTotalFee(BigDecimal.valueOf(Integer.parseInt(map.get("total_fee"))).divide(new BigDecimal(100)).doubleValue());
                        msisdnOrderBean.setTransactionId(map.get("transaction_id"));
                        msisdnOrderBean.setTrafficNo(DateUtils.getNowDataTime() + ApiUtils.getFourRandom()); //年月日时分秒+四位随机数
                        trafficCardListService.insertTrafficCardList(msisdnOrderBean);
                    }
                }
            }
            resXml = XMLUtil.setXML("SUCCESS", "OK");
        } else {
            resXml = "<xml>" + "<return_code><![CDATA[FAIL]]></return_code>"
                    + "<return_msg><![CDATA[通知签名验证失败]]></return_msg>" + "</xml> ";
            logger.info("通知签名验证失败");
        }
    }else{
        resXml =XMLUtil.setXML("FAIL", "签名不一致");
    }

    writer.write(resXml);
    writer.flush();
    writer.close();

运用到的 PrepayIdRequestHandler 工具类

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public class PrepayIdRequestHandler extends RequestHandler {

public PrepayIdRequestHandler(HttpServletRequest request,
                              HttpServletResponse response) {
    super(request, response);
}

public String createMD5Sign() {
    StringBuffer sb = new StringBuffer();
    Set es = super.getAllParameters().entrySet();
    Iterator it = es.iterator();
    while (it.hasNext()) {
        Map.Entry entry = (Map.Entry) it.next();
        String k = (String) entry.getKey();
        String v = (String) entry.getValue();
        sb.append(k + "=" + v + "&");
    }

    String params=sb.append("key="+ConstantUtil.APP_KEY).substring(0);
    String sign = MD5Util.MD5Encode(params, "utf8");
    return sign.toUpperCase();
}

// 提交预支付
public String sendPrepay() throws Exception {
    String prepayid = "";

原文 https://segmentfault.com/a/1190000020908544

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