【在线支付】在线支付代码详解

前言：    

   上一篇文章中（【在线支付】在线支付流程分析）说道，为了保证数据安全，网站把源数据和hmac码发送到第三方，那么，在代码中是如何实现的呢？接收到付款成功的消息，又是如何响应的呢？以向易宝支付为例

1、向易宝发送支付请求

导入算法工具类PaymentUtil

import cn.itcast.utils.PaymentUtil;

public class PayServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {//获取的支付信息：ID，交易金额，订单号String orderid = request.getParameter("orderid");String money = request.getParameter("money");String pd_Id = request.getParameter("pd_FrpId");//源数据的规范，顺序不能变（参见“易宝支付产品通用接口帮助文档”支付请求参数说明）String p0_Cmd = "Buy";  //业务类型String p1_MerId = "10001126856";// 商户编号（银行卡号），向此卡号支付String p2_Order = orderid;      //商户订单号String p3_Amt = money;           // 付款金额String p4_Cur = "CNY";          // 交易币种String p5_Pid = "";                // 商品名称String p6_Pcat = "";             // 商品种类String p7_Pdesc = "";           // 商品描述String p8_Url = "http://localhost/day20pay/callback";  // 商户接收支付成功数据的地址                 String p9_SAF = ""; // 送货地址String pa_MP = ""; // 商户扩展信息String pd_FrpId = this.pd_FrpId;// 支付通道编码String pr_NeedResponse = "1"; // 应答机制//秘钥（在算法工具类PaymentUtil中，需用到秘钥）String keyValue = "69cl522AV6q613Ii4W6u8K6XuW8vM1N6bFgyv769220IuYe9u37N4y7rI4Pl";//根据源数据生成hmac码String hmac = PaymentUtil.buildHmac(p0_Cmd, p1_MerId, p2_Order, p3_Amt, p4_Cur,p5_Pid, p6_Pcat, p7_Pdesc, p8_Url, p9_SAF, pa_MP, pd_FrpId,pr_NeedResponse, keyValue);              // 将所有参数 发送给 易宝指定URLrequest.setAttribute("pd_FrpId", pd_FrpId);request.setAttribute("p0_Cmd", p0_Cmd);request.setAttribute("p1_MerId", p1_MerId);request.setAttribute("p2_Order", p2_Order);request.setAttribute("p3_Amt", p3_Amt);request.setAttribute("p4_Cur", p4_Cur);request.setAttribute("p5_Pid", p5_Pid);request.setAttribute("p6_Pcat", p6_Pcat);request.setAttribute("p7_Pdesc", p7_Pdesc);request.setAttribute("p8_Url", p8_Url);request.setAttribute("p9_SAF", p9_SAF);request.setAttribute("pa_MP", pa_MP);request.setAttribute("pr_NeedResponse", pr_NeedResponse);request.setAttribute("hmac", hmac);request.getRequestDispatcher("/confirm.jsp").forward(request, response);}

2、付款成功后，回调程序

public class CallbackServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 验证请求来源和数据有效性// 阅读支付结果参数说明// System.out.println("==============================================");String p1_MerId = request.getParameter("p1_MerId");String r0_Cmd = request.getParameter("r0_Cmd");String r1_Code = request.getParameter("r1_Code");String r2_TrxId = request.getParameter("r2_TrxId");String r3_Amt = request.getParameter("r3_Amt");String r4_Cur = request.getParameter("r4_Cur");String r5_Pid = request.getParameter("r5_Pid");String r6_Order = request.getParameter("r6_Order");String r7_Uid = request.getParameter("r7_Uid");String r8_MP = request.getParameter("r8_MP");String r9_BType = request.getParameter("r9_BType");String rb_BankId = request.getParameter("rb_BankId");String ro_BankOrderId = request.getParameter("ro_BankOrderId");String rp_PayDate = request.getParameter("rp_PayDate");String rq_CardNo = request.getParameter("rq_CardNo");String ru_Trxtime = request.getParameter("ru_Trxtime");// hmacString hmac = request.getParameter("hmac");// 利用本地密钥和加密算法 加密数据String keyValue = "69cl522AV6q613Ii4W6u8K6XuW8vM1N6bFgyv769220IuYe9u37N4y7rI4Pl";boolean isValid = PaymentUtil.verifyCallback(hmac, p1_MerId, r0_Cmd,r1_Code, r2_TrxId, r3_Amt, r4_Cur, r5_Pid, r6_Order, r7_Uid,r8_MP, r9_BType, keyValue);if (isValid) {// 有效if (r9_BType.equals("1")) {// 浏览器重定向response.setContentType("text/html;charset=utf-8");response.getWriter().println("支付成功！订单号：" + r6_Order + "金额：" + r3_Amt);} else if (r9_BType.equals("2")) {// 服务器点对点，来自于易宝的通知System.out.println("收到易宝通知，修改订单状态！");//// 回复给易宝success，如果不回复，易宝会一直通知response.getWriter().print("success");}} else {throw new RuntimeException("数据被篡改！");}}}

   整个支付的思路很简单，发送请求和支付后相应，具体的解释，还是要看代码注释，顺着代码走一遍，就可以理清了。

参考：《网上商城SSH》，在线支付demo