程序主要是基于套接字（Socket）进行网络编程的，采用的是TCP协议，TCP协议是面向连接的且是全双工的，即两个主机上的进程（比如进程A、进程B），一旦建立好连接，那么数据就既可以由A流向B，也可以由B流向A。此程序采用的是完全点对点的模式进行连接，即每台主机即是服务器又是客户端，因为它需要进行端口的侦听，所以在连接的时候必须知道各主机的IP地址和端口号。有了对方的IP和端口后两主机就可以进行握手过程，确认连接成功后就可以进行网络对话了。-Program is mainly based on socket (Socket) for network programming, using the TCP protocol, TCP protocol is connection-oriented and is full duplex, that is, the process of the two hosts (such as process A, process B) Once established a good connection, the data flow for both the A B, can also flow from the B A. This procedure uses a fully connected point to point mode, each host is the server that is the client, because it requires the listening port, so when the connection must know the host' s IP address and port number . With the other two host IP and port can be carried out after the handshake process, confirm the connection to the network after a successful dialogue.