/**
 * @param $appKey     分配的APP_KEY
 * @param $secretKey  分类的服务端私有KEY
 * @return string     返回生成的sign
 *
 * $postParams = [
 *   'app_key' => 'qh97',
 *   'product_id' => 'AC01',
 *   'product_name' => '能量豆',
 *   'app_order_id' => '1232132133',
 *   'app_district' => 1,
 *   'app_server'   => 2,
 *   'app_user_id'  => 'test01',
 *   'app_user_name' => 'test',
 *   'money_amount' => 2.13,
 *   'pa_open_uid' => 1,
 *   'pa_open_order_id' => 'ZX0001',
 *   'app_extra1' => '',
 *   'app_extra2' => ''
 * ]
 *
 */
 function genCallGameSign($appKey, $secretKey) {
    $postParams = $_POST;
    if (isset($postParams['sign'])) {
        unset($postParams['sign']);
    }
    ksort($postParams);
    $sortedParams = [];
    foreach ($params as $k => $v) {
        $sortedParams[] = $k . "=" . $v;
    }
    return md5($appKey . $secretKey . join("&", $sortedParams));
 }

                                
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
public class TestJavaSign {
    public static void main(String[] args) throws Exception {
       /**
        *  这里参数都应是从POST过来的请求中获取,这里模拟request请求数据
        */
       Map requestParams = new HashMap();
       requestParams.put("app_key", "qh97");
       requestParams.put("product_id", "123456");
       requestParams.put("product_name", "abc");
       requestParams.put("app_order_id", "12343455657");
       requestParams.put("app_district", "1");
       requestParams.put("app_server", "2");
       requestParams.put("app_user_id", "13189");
       requestParams.put("app_user_name", "app_name");
       requestParams.put("money_amount", "10");
       requestParams.put("pa_open_uid", "1368");
       requestParams.put("pa_open_order_id", "12342134");
       requestParams.put("app_extra1", "extra");
       requestParams.put("app_extra2", "extra");
       requestParams.put("sign", "88988f0e5c3fe758da6122303fe72835");
       payedCallGame("qh97", "124123579123591235u912uu9quwerqwe", requestParams);
    }
    /**
     * 验证请求是否合法
     *
     * @param appKey 服务端配置的appkey值
     * @param secretKey 服务端配置的secretKey值
     * @param requestParams 请求参数
     */
    public static void payedCallGame(String appKey, String secretKey, Map requestParams) {
        /**
         * 从POST 请求参数拿到需要签名的参数
         */
        Map signParams = new HashMap();
        signParams.put("app_key", requestParams.get("app_key"));
        signParams.put("product_id", requestParams.get("product_id"));
        signParams.put("product_name", requestParams.get("product_name"));
        signParams.put("app_order_id", requestParams.get("app_order_id"));
        signParams.put("app_district", requestParams.get("app_district"));
        signParams.put("app_server", requestParams.get("app_server"));
        signParams.put("app_user_id", requestParams.get("app_user_id"));
        signParams.put("app_user_name", requestParams.get("app_user_name"));
        signParams.put("money_amount", requestParams.get("money_amount"));
        signParams.put("pa_open_uid", requestParams.get("pa_open_uid"));
        signParams.put("pa_open_order_id", requestParams.get("pa_open_order_id"));
        signParams.put("app_extra1", requestParams.get("app_extra1"));
        signParams.put("app_extra2", requestParams.get("app_extra2"));
        String signVal = genGameCallSign(appKey, secretKey, signParams);
        if (signVal.equals(requestParams.get("sign"))) {
            //验证成功，合法的支付完成游戏发放请求
            //System.out.println("验证成功，合法的支付完成游戏发放请求");
        } else {
            //验证失败或者非法请求
            //System.out.println("验证失败或者非法请求" + signVal);
        }
    }

     public static String genGameCallSign(String appKey, String secretKey, Map params) {
         String[] sortedParams = new String[params.size()];
         params.keySet().toArray(sortedParams);
         Arrays.sort(sortedParams);
         StringBuilder sb = new StringBuilder();
         for (String key: sortedParams) {
             sb.append(String.format("&%s=%s", key, params.get(key)));
         }
         /**
          * 请自己提供md5函数
          */
         return MD5.encode(appKey + secretKey + sb.toString().substring(1));
     }
}