// 假设 iframe 页面计算各个参数后,url 为:https://iframe.custom.com/path?param1=value1¶m2=value2¶mN=valueN
String url = "https://iframe.custom.com/path?param1=value1¶m2=value2¶mN=valueN";
String appSecret = "6226D081B3DB401E94AB61A864DF93B2"; // 取扩展与集成页面 开发者ID 下的 AppSecret
String queryString = "param1=value1¶m2=value2¶mN=valueN"; // 可通过 javax.servlet.http.HttpServletRequest#getQueryString() 获取
String signature = org.apache.commons.codec.digest.DigestUtils.sha1Hex(appSecret + queryString);
// 得到最终的url
url = url + "&signature=" + signature;