这个是《java实用程序设计100例》 袁海燕主编的源码，源码都是正确。-This is the "java utility designed to 100 cases," Yuan Haiyan editor source code, source code is correct.

Java网络编程，基于TCP的套接字编程，基于UDP的套接字编程，URL和URI，一个实用的下载程序。-Java network programming, TCP socket-based programming, socket programming based on UDP, URL and URI, download a utility program.