可以获取本机的公网IP地址，可以解析服务器的域名，可以测试是否可以访问某个网站，尤其是针对不同的网络环境对服务器解析出错有较好的解决~-Can get the public IP address of the machine, can resolve the domain name of the server, you can test whether you can access a website, especially server parsing error for different