将文件从SFTP直接下载到HTTP响应,而不使用中间文件

我试图使用Java JSsch库通过SFTP下载一个文件。我成功地将文件下载到本地目录**但是,我只需要将文件直接下载到浏览器,而不需要提供任何本地目标路径(例如文件在Chrome中的下载方式)。我正在使用Spring控制器AngularJS Promise捕捉响应。下面是我的代码。

@RequestMapping(value = "/downloadAttachment", method = RequestMethod.POST,
                produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public void downloadAttachment(
        @RequestParam(value = "fileName") String fileName,
        @RequestParam(value = "filePath") String filePath,
        @RequestParam(value = "fileId") String fileId,
        HttpServletResponse response, Locale locale) throws Exception {
    InputStream is = null;
    if(!fileName.isEmpty() && !filePath.isEmpty() && !fileId.isEmpty()){
        String directory = filePath;
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        JSch ssh = new JSch();
        Session session = ssh.getSession(sftpLogin, sftpAddress, 22);
        session.setConfig(config);
        session.setPassword(sftpPassword);
        session.connect();
        logger.info("Connection to server established");
        Channel channel = session.openChannel("sftp");
        channel.connect();

        ChannelSftp sftp = (ChannelSftp) channel;
        sftp.cd(directory);
        is = sftp.get(fileName);
        channel.disconnect();
        session.disconnect();
    }
    IOUtils.copy(is, response.getOutputStream());
    is.close();
    response.getOutputStream().close();
    response.flushBuffer();
}

MediaType.APPLICATION_OCTET_STREAM_VALUE

java.io。IOException:管道关闭 fill(ChannelSftp.java:2909) jcraft.jsch.ChannelSftp.header(ChannelSftp.java:2935) access$500(ChannelSftp.java:36) jcraft.jsch.ChannelSftp$2.read(ChannelSftp.java:1417) 复制(IOUtils.java:999)