Question

I am using the following code to upload files to a FTP, the files get uploaded – the issue is with xls, pdf and video files, they get corrupted. Txt, sql remain intact, i have checked this in the FTP directly. I am thinking its something to do with UTF8.GetBytes? Code is below

                Dim URI As String = Url & "/" & fileName
                Dim ftp As System.Net.FtpWebRequest = CType(FtpWebRequest.Create(URI), FtpWebRequest)
                ftp.Credentials = New System.Net.NetworkCredential(Username, Password)
                ftp.Proxy = Nothing
                ftp.KeepAlive = False
                ftp.UsePassive = False
                ftp.Method = System.Net.WebRequestMethods.Ftp.UploadFile

                Dim sourceStream As New StreamReader(file.InputStream)
                Dim fileContents As Byte() = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd())
                sourceStream.Close()


                ftp.ContentLength = fileContents.Length
                ftp.UsePassive = True

                Dim requestStream As Stream = ftp.GetRequestStream()
                requestStream.Write(fileContents, 0, fileContents.Length)
                requestStream.Close()

                Dim response As FtpWebResponse = DirectCast(ftp.GetResponse(), FtpWebResponse) 

Any help would be greatly appreciated.

Answer 1

This is the problem:

Dim fileContents As Byte() = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd())

You’re reading the stream as a string, as if it’s UTF-8-encoded text, then converting it back to bytes again. Why would you do this? The files in question aren’t UTF-8-encoded text, so you shouldn’t treat them that way.

Read binary data from the stream, never converting it into text unless you’re sure it really is text data. It’s not clear what the type of file is here, but hopefully you can get the length without reading the whole thing into memory. You can then use:

file.InputStream.CopyTo(requestStream)

to copy all the data. Note that you should use Using statements instead of manually closing streams, to avoid leaving them open if exceptions are thrown.