Single-File PHP Implementation for Alipay and WeChat Payments

Many online tutorials for PHP Alipay integration are overly complex and require numerous files; this guide consolidates the process into a single PHP file that also supports WeChat payments, with links to the GitHub repositories dedemao/alipay and dedemao/weixinPay .

To ensure compatibility with the WeChat browser, the solution depends on two additional files provided by Alipay’s official demo (alipay_in_weixin_demo): ap.js and pay.htm .

Environment requirements include PHP 5.0 or higher with CURL and SSL extensions enabled.

Key configuration items at the top of the file must be filled in: the App ID, return and notify URLs, a unique order number, payment amount, order title, and the merchant private key (RSA2 or RSA). The private key should be generated according to Alipay’s documentation ( link 1 , link 2 ).

The core PHP code defines an AlipayService class with methods to construct request parameters, generate signatures, and handle character‑set conversion. Important methods include:

<code>&lt;?php
header('Content-type:text/html; Charset=utf-8');
$appid = 'xxxxx';
$returnUrl = 'http://www.xxx.com/alipay/return.php';
$notifyUrl = 'http://www.xxx.com/alipay/notify.php';
$outTradeNo = uniqid();
$payAmount = 0.01;
$orderName = '支付测试';
$signType = 'RSA2';
$saPrivateKey = 'MIIEpAIBAAKCAQEA...';
$aliPay = new AlipayService($appid,$returnUrl,$notifyUrl,$saPrivateKey);
$payConfigs = $aliPay->doPay($payAmount,$outTradeNo,$orderName,$returnUrl,$notifyUrl);
// class definition follows with doPay, generateSign, sign, checkEmpty, getSignContent, characet
?&gt;</code>

After creating the payment configuration, the script builds a query string and checks whether the request originates from the WeChat browser using the isWeixin() function. If true, it loads ap.js and invokes _AP.pay(gotoUrl) ; otherwise, it redirects the user directly to Alipay’s gateway URL.

Additional documentation links are provided for reference, and the article concludes with a reminder to ensure the configuration header information is complete and the merchant private key matches the selected signature algorithm.