基于TCP的文件传输，分为服务器端和客户端，客户端可以传输任意大小、任意格式的文件到服务器端，该源代码很好使，也易懂！-TCP-based file transfer, is divided into server-side and client, the client can transfer any size, any format of documents to the server side, the source code very well so that is also easy