ftp读取图片并转Base64

 public String download(String ftpUrl,String sfzh){
        FTPClient ftpClient = new FTPClient();
        InputStream inputStream = null;
        String re=null;
        try {
            ftpClient.connect(ftp_ip,ftp_port);
            ftpClient.login(ftp_username, ftp_password);
            ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
            //是否成功登录服务器
            int reply = ftpClient.getReplyCode();
            if (!FTPReply.isPositiveCompletion(reply)) {
                ftpClient.disconnect();
            }
            //跳转到指定目录
            ftpClient.changeWorkingDirectory(ftpUrl);
            //5.遍历下载的目录
            FTPFile[] fs = ftpClient.listFiles();
            for (FTPFile ff : fs){
                //解决中文乱码问题，两次解码
                byte[] bytes=ff.getName().getBytes("iso-8859-1");
                String fileName=new String(bytes,"utf-8");
                if(sfzh.equals(fileName)){
                    inputStream = ftpClient.retrieveFileStream(fileName);
                }
            }

            if (inputStream != null) {
                byte[] data=null;
                data=new byte[inputStream.available()];
                BASE64Encoder encoder=new BASE64Encoder();
                re=encoder.encode(data);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(ftpClient.isConnected()){
                try{
                    ftpClient.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                }
            }
            if(null != inputStream){
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return re;
    }