说明：  聊天室实例。其分为服务器和客户两部分。客户首先与服务器建立TCP连 接，并发送客户名称给服务器，然后就可以通过服务器发信息给其他已连接的客户，同时通 过服务器接收其他客户的信息。
(Examples of chat rooms. Divided into two parts, server and client. First of all, the establishment of client and server TCP connection, and send the customer name to the server, then the information can be made through the server is connected to other customers, while other customers receive through the server information.)