java实现ftp有两种方式，一种是sun.net.ftp功能比较简单 ，一种是enterprisedt.net.ftp功能十分强大，这个就是后者，包括源码-in java , there are two jars to make sure the ftp expression , one way si sun.net.ftp ,the other is enterprisedt.net.ftp,this package is the latter , including the source