PayPal在线支付验证与IPN实现

1. //从 PayPal 出读取 POST 信息同时添加变量?cmd?  
2.     Enumeration en = request.getParameterNames();  
3.     String str = "cmd=_notify-validate";  
4.     while (en.hasMoreElements()) {  
5.         String paramName = (String) en.nextElement();  
6.         String paramValue = request.getParameter(paramName);  
7.         str = str + "&" + paramName + "="  
8.                 + URLEncoder.encode(paramValue, "utf-8");  
9.         //此处的编码一定要和自己的网站编码一致，不然会出现乱码，paypal回复的通知为‘INVALID’  
10.     }  
11.     System.out.println("paypal传递过来的交易信息:" + str);  
12.     //建议在此将接受到的信息 str 记录到日志文件中以确认是否收到 IPN 信息  
13.     //将信息 POST 回给 PayPal 进行验证  
14.     //设置 HTTP 的头信息  
15.     //在 Sandbox 情况下，设置：  
16.     URL u = new URL("https://www.sandbox.paypal.com/cgi-bin/webscr");  
17.     //正式环境  
18.     //      URL u = new URL("https://www.paypal.com/cgi-bin/webscr");  
19.     URLConnection uc = u.openConnection();  
20.     uc.setDoOutput(true);  
21.     uc.setRequestProperty("Content-Type",  
22.             "application/x-www-form-urlencoded");  
23.     PrintWriter pw = new PrintWriter(uc.getOutputStream());  
24.     pw.println(str);  
25.     pw.close();  
26.     //接受 PayPal 对 IPN 回发的回复信息  
27.     BufferedReader in = new BufferedReader(new InputStreamReader(  
28.             uc.getInputStream()));  
29.     String res = in.readLine();