这是一个GUI聊天小程序。客户端与服务器端都可以由用户输入数据向对方发送，把接收数据部分放在线程中，它始终在后台运行，一旦对方发数据就显示，不影响自己发送-This is a GUI chat applet. Client and server-side data can be entered by the user to send to each other, some of the received data on the thread, it is always running in the background, once the other side send data to show, does not affect its own transmission