实现对文件的加解密，采用DES算法（当然JAVA已经实现，我只调用了一下）。可以加密的文件类型不限，不支持文件夹加密-The realization of the document encryption and decryption using DES algorithm (JAVA course has been achieved, I can only call a moment). Can open the encrypted file type, folder does not supp