说明：  Socket 编程 Socket是应用层与TCP/IP协议族通信的中间软件抽象层，它是一组接口。在设计模式中，Socket其实就是一个门面模式，它把复杂的TCP/IP协议族隐藏在Socket接口后面，对用户来说，一组简单的接口就是全部，让Socket去组织数据，以符合指定的协议。
(Socket Programming Socket is the application layer and the TCP/IP protocol suite communications middleware abstraction layer, which is a set of interfaces. In the design mode, Socket is actually a facade pattern, it is the complicated TCP/IP protocol suite hidden behind the Socket interface for users, a group of simple interface that is all, let Socket to organize data in order to comply with the specified agreement.)