socket 的简单服务器端程序，不过功能有限，只能接收分步，有兴趣可以改改，使它可以像QQ那样，再联系我，再交流一下-socket simple server-side program, but limited only to receive step-by-step, are interested in can be changed so that it can be done as QQ, and then contact me, and then exchange