一个演示工作原理命令的ftp服务器程序，使用信号量和临界区解决多线程的同步和互斥问题　-a demonstration of principle orders ftp server, the use of volume and signal to solve critical multithreading and synchronization of Mutual Exclusion

呵呵，java写的。可以实现多线程下载。-Oh, it was the java. Multithreading can achieve download.