FTP协议不匹配 抛出异常

 FTPClient ftpClient = null;
        try {
            response.setCharacterEncoding(Constants.ENCODING_UTF8);
            String type = request.getParameter("type");
            String fileName = request.getParameter("name");
            String tenantCode = request.getParameter("tenantCode");
            ftpClient = FtpUtils.getFileClient(tenantCode, type);
            InputStream imageIn = ftpClient.retrieveFileStream(fileName);
            OutputStream output = response.getOutputStream();// 得到输出流  
            logger.debug("加载文件：/" + tenantCode + "/" + fileName);
            byte [] temp = new byte[1024];
            int len = -1;
            while((len = imageIn.read(temp)) != -1){
                output.write(temp,0,len);
            }
            if(output != null){
                output.flush();
                output.close();
            }
            if (imageIn != null) {
                imageIn.close();
            }
            ftpClient.logout();
        } catch (Exception e) {
            e.printStackTrace();
            logger.error("文件下载失败:" + e.getMessage());
        } finally {
            if (ftpClient.isConnected()) {
                ftpClient.disconnect();
            }
        }

总是抛异常

Server Reply: Protocol mismatch.
Server Reply: SSH-2.0-OpenSSH_5.3

这个怎么解决呢？

http://jerval.iteye.com/blog/2150030