有一个服务器端 有多个客户端

先启动服务器，服务器端永不退出，或者信号退出。

启动客户端，输入一个昵称，连接服务器，把昵称发给服务器

服务器收到客户的连接请求后，启动一个新的线程与客户端进行交互-There is a server has multiple clients

First start the server, the server never quit, or exit signal.

Start the client, enter a nickname, connect to the server, the nickname to the server

After the server receives a connection request of customers, start a new thread to interact with the client