实现HTTP协议和FTP协议的多线程下载工具。该工具需要具备多线程分段下载的功能，同时还应实现“断点续传”功能-HTTP FTP

用java编写的多线程下载工具，支持断点续传，支持ftp/http协议，支持下载分类跳转，做得很初级，很多功能没实现-Prepared using multi-threaded java download tools, support for HTTP, support ftp/http protocols support download categories jump, doing a good primary, a lot of features did not achieve