说明：  java聊天程序,通过socket编程实现网络通信。在两台机器（在一台机器上也可）上依次启动服务器、客户端；在客户端输入正确的服务器地址后确认连接是否成功，若成功则可以在客户端和服务器之间实现互相收发数据（任何一端都可以是发送端，相应地也可以是接收端），并且都可以用特定字符串控制退出（这里是用bye）；同时客户端与服务器应该能实现地检测大对方的运行状态。并且对特定状态作出正确的反应行为。
(java chat program, through the socket programming network communications. In the two machines (in one machine can be) in order to start the server, client the client to enter the correct server address to confirm connection is successful, if success can be in the client and server to send and receive data between each other (Any one can be the sending end, can also be a corresponding receiving end), and are able to withdraw from a particular string control (here is a bye) At the same time, client and server should be able to detect large realize each other)