我正在尝试使用sftp连接从web应用程序下载文件。我可以上传一个文件，但从下面的代码一个虚拟文件正在下载，但文件内没有内容。

InputStream in = channelSftp.get(myFile);

// if you want to use a relative path to context root:
String relativePath = getServletContext().getRealPath("");
System.out.println("relativePath = " + relativePath);

// obtains ServletContext
ServletContext context = getServletContext();

// gets MIME type of the file
String mimeType = context.getMimeType(path);
if (mimeType == null) {
    // set to binary type if MIME mapping not found
    mimeType = "application/octet-stream";
}

// modifies response
response.setContentType(mimeType);
response.setContentLength((int) downloadFile.length());

// forces download
String headerKey = "Content-Disposition";
String headerValue = String.format("attachment; filename=\"%s\"",
    downloadFile.getName());
response.setHeader(headerKey, headerValue);

// obtains response's output stream
OutputStream outStream = response.getOutputStream();

byte[] buffer = new byte[4096];
int bytesRead = -1;

System.out.println( in +"input streem in download file");
while ((bytesRead = in .read(buffer)) != -1) {

    System.out.println(buffer + " bytesRead in download");
    outStream.write(buffer, 0, bytesRead);
} in .close();

outStream.close();

在上面的代码中，我使用 InputStream in = channelSftp.get(myFile); . 有人能认出我的错误吗？