说明：  设计一个p2p聊天软件，由多个聊天客户端和一个中心服务器组成。各个聊天客户端可以两两相互发送消息。目的在于设计GUI,多线程和套接字编程。各个客户端用IP地址和TCP/IP监听端口号进行标识。每个客户提供一个名字，方便其它客户端。 此设计由两部分组成。 部分一：p2p聊天中各个成员管理。每个成员称为一个peer,要有一个中心的服务处理peer的登记和对已经登记的peer进行更新。 步骤1：一个peer选择一个名字，通过登记界面进行登记。 步骤2：服务器拥有一个公有IP，在一个众所周知的端口进行监听。Peer向服务器发送‘register’请求，同时发送自己的登记信息（如自己取的名字，自己的监听端口号等）。服务器收到‘register’请求后，如果这是每一个登记请求，服务器建立一个用于记录已经登记peer的列表（Peer List），否则更新Peer List。 步骤3：服务器向来登记的peer发送Peer List。PeerList 由一些活跃的peer组成，一个活跃的peer是在最近30秒内进行登记的peer
(The design of a p2p chat software, multiple chat client and a central server. Each chat client can two two send each other messages. Aims to design the GUI, multithreading and socket programming. Each client IP address and TCP/IP listening port number for identification. Each customer to provide a name, and convenient to other clients. This design consists of two parts. Part one: p2p chat management. Each member is called a peer, have a central service to deal with peer registration and to update already registered peer. Step 1: a peer to select a name to be registered through the registration interface. Step 2: The server has a public IP, in a well-known port listening. Peer to the server send register request, send the registration information (such as the name they take, their own listening port number, etc.). The server receives the request of the register , if this is per a registration request, the server to establish one for the record have been registered to the list o)