I've been reading gobs of articles on FTP upload in ASP.NET recently and they all seem to make sense, but every time I've tried implementing them I either get an empty file uploaded, or no file at all. Here are some of the articles I've been reading:
They're all great articles, but like I said, having issues :(
I know exactly what the problem is but I don't know how to fix it. I can pass the file name from the FileUpload control, but the path does not exist for security concerns. However, the StreamReader object requires the fully qualified path of the file to be uploaded, so how the heck do I get that? I'm at my wits end! >.<
Let's use the example by John Peterson that I linked above. Here's the code:
Protected Sub btnUploadFile_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim myFtpWebRequest As FtpWebRequest
Dim myFtpWebResponse As FtpWebResponse
Dim myStreamWriter As StreamWriter
myFtpWebRequest = WebRequest.Create("ftp://ftp_server_name/filename.ext")
myFtpWebRequest.Method = WebRequestMethods.Ftp.UploadFile
myFtpWebRequest.UseBinary = True
myStreamWriter = New StreamWriter(myFtpWebRequest.GetRequestStream())
'IT BREAKS HERE BECAUSE THE CLIENT PATH IS WRONG!!
myStreamWriter.Write(New StreamReader(Server.MapPath("filename.ext")).ReadToEnd)
myStreamWriter.Close()
myFtpWebResponse = myFtpWebRequest.GetResponse()
myFtpWebResponse.Close()
End Sub
See? No data in the uploaded file :(
Now my latest implementation looks like this, but the uploaded file is much larger than the source, and corrupted. Seriously, what the heck am I doing wrong? I've been two LONG days at this, grrr...
Protected Sub btnUploadFile2_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim myFtpWebRequest As FtpWebRequest
Dim myFtpWebResponse As FtpWebResponse
filename = Path.GetFileName(FileUpload1.FileName)
myFtpWebRequest = CType(WebRequest.Create(ftpServer + ftpPath + filename), FtpWebRequest)
myFtpWebRequest.Method = WebRequestMethods.Ftp.UploadFile
myFtpWebRequest.UseBinary = True
'NEW APPROACH USING THE STREAM OF THE FILE FROM THE FileUpload Control
'CORRECT BYTE LENGTH - in sourceStream.BaseStream
Dim sourceStream As New StreamReader(FileUpload1.FileContent)
'WRONG BYTE LENGTH - in sourceStream.ReadToEnd()
Dim fileContents As Byte() = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd())
sourceStream.Close()
myFtpWebRequest.ContentLength = fileContents.Length
Dim requestStream As Stream = myFtpWebRequest.GetRequestStream()
requestStream.Write(fileContents, 0, fileContents.Length)
requestStream.Close()
myFtpWebResponse = CType(myFtpWebRequest.GetResponse(), FtpWebResponse)
myFtpWebResponse.Close()
End Sub
Thanks ever so much to Adam Maras for the amazing answer. I'll leave my blunders here for others to benefit who find this thread ;)
First of all, you must upload through the web server if you're going to use ASP.NET like this. Without installing a plugin on the client's browser or using an ActiveX control (or similar) you absolutely cannot upload directly from the client machine to the FTP server.
I assume you're uploading binary files; if that's the case, the way you're using StreamReader
s and StreamWriter
s could be corrupting the binary contents of the file. Instead, we can use the Stream.CopyTo
method to move the data verbatim from one stream to the other.
I've modified your method to use this pattern instead:
Protected Sub btnUploadFile2_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim myFtpWebRequest As FtpWebRequest
Dim myFtpWebResponse As FtpWebResponse
filename = Path.GetFileName(FileUpload1.FileName)
myFtpWebRequest = CType(WebRequest.Create(ftpServer + ftpPath + filename), FtpWebRequest)
myFtpWebRequest.Method = WebRequestMethods.Ftp.UploadFile
myFtpWebRequest.UseBinary = True
Dim myFileStream As Stream = FileUpload1.FileContent
myFtpWebRequest.ContentLength = myFileStream.Length
Dim requestStream As Stream = myFtpWebRequest.GetRequestStream()
myFileStream.CopyTo(requestStream)
requestStream.Close()
myFtpWebResponse = CType(myFtpWebRequest.GetResponse(), FtpWebResponse)
myFtpWebResponse.Close()
End Sub