C/S模式下的参考代码，十分有用。值得参考-the reference source codes base on C/S model. Worthly for coding reference

套接字连接最基础的。采用B/S模式。分为服务器端和客户端两部分。请求发送后 服务器发送。客户端同步收到。-The most basic socket connection. Uses B/S mode. Divided into server and client in two parts. After the server sends a request is sent. Client synchronization received.