String filePath="C:\\Java-Exception.ppt";
                File distFile = new File(filePath); 
                String contect=FileMaster.file2String(distFile,"gbk");
        String contect1=encode(contect,"gbk");//加密
        String contect2=decode(contect1,"gbk"); //解密
        String filePathAndName="C:\\base64Java-Exception.ppt";
                FileMaster.newFile(filePathAndName, contect2);