Develop Reference

When calling FtpWebRequest.DownloadFile after FtpWebRequest.UploadFile why am I getting an exception?

I have two methods (C# 4.8): one that uploads a file to a server directory using FTP, and one that downloads a file from a server using FTP. Each of these work fine independently. However, when I call the UploadFile(...) method followed by the Download method, an exception is thrown on the FtpWebRequest.Create(...) method in the DownloadFile(...) method.
I can call DownloadFile(...) successively without problems.
Am I missing something, perhaps to close the connection?
The exception is:
Message: "The remote server returned an error: 226-File successfully transferred\r\n226 1.707 seconds (measured here), 4.59 Mbytes per second\r\n."
InnerException: null
Status: ProtocolError
My code is:
public void UploadFile(FileInfo SourceFile, string Domain, string TargetFileName, string Username, string Password)
{
FtpWebRequest _FTPRequest = (FtpWebRequest)WebRequest.Create(Domain + TargetFileName);
_FTPRequest.Credentials = new NetworkCredential(Username, Password);
_FTPRequest.Method = WebRequestMethods.Ftp.UploadFile;
_FTPRequest.UseBinary = true;
_FTPRequest.KeepAlive = false;
_FTPRequest.UsePassive = true;
using (FileStream fileStream = SourceFile.OpenRead())
using (FtpWebResponse response = (FtpWebResponse)_FTPRequest.GetResponse())
using (Stream ftpStream = _FTPRequest.GetRequestStream())
{
byte[] buffer = new byte[1024];
int iRead;
while ((iRead = fileStream.Read(buffer, 0, buffer.Length)) > 0)
ftpStream.Write(buffer, 0, iRead);
}
}
public void DownloadFile(ref byte[] TargetArray, string Domain, string SourceFileName, string Username, string Password)
{
FtpWebRequest _FTPRequest = (FtpWebRequest)WebRequest.Create(Domain + SourceFileName); // exception is thrown here //
_FTPRequest.Credentials = new NetworkCredential(Username, Password);
_FTPRequest.Method = WebRequestMethods.Ftp.DownloadFile;
_FTPRequest.UseBinary = true;
_FTPRequest.KeepAlive = false;
_FTPRequest.UsePassive = true;
using (FtpWebResponse response = (FtpWebResponse)_FTPRequest.GetResponse())
using (Stream ftpStream = response.GetResponseStream())
{
byte[] buffer = new byte[1024];
int totalRead = 0;
int iRead;
while ((iRead = ftpStream.Read(buffer, 0, buffer.Length)) > 0)
{
if (buffer.Length > iRead) Array.Resize<byte>(ref buffer, iRead);
Array.Resize<byte>(ref TargetArray, TargetArray.Length + iRead);
buffer.CopyTo(TargetArray, totalRead);
totalRead += iRead;
}
}
}

It appears that when I called _FTPRequest.GetResponse() before _FTPRequest.GetRequestStream(), it actually opened two separate requests and they were conflicting. I'm not yet clear as to why it only affected the subsequent download method, but once I removed that line completely, the methods worked as expected.

FTP request download a file and delete immediately

I have got a code to download a file using ftprequest
FtpWebRequest requestFileDownload = (FtpWebRequest)WebRequest.Create("ftp://localhost/Source/" + fileName);
requestFileDownload.Credentials = new NetworkCredential("khanrahim", "arkhan22");
requestFileDownload.Method = WebRequestMethods.Ftp.DownloadFile;
FtpWebResponse responseFileDownload = (FtpWebResponse)requestFileDownload.GetResponse();
Stream responseStream = responseFileDownload.GetResponseStream();
FileStream writeStream = new FileStream(localPath + fileName, FileMode.Create);
int Length = 2048;
Byte[] buffer = new Byte[Length];
int bytesRead = responseStream.Read(buffer, 0, Length);
while (bytesRead > 0)
{
writeStream.Write(buffer, 0, bytesRead);
bytesRead = responseStream.Read(buffer, 0, Length);
}
responseStream.Close();
writeStream.Close();
Now my need is that i need to delete the file from ftpserver once download is complete using the same requset.
I did try appending
requestFileDownload.Method = WebRequestMethods.Ftp.deleteFile;
before closing the request ..But it is not working.
How can i delete the file using the same request.

Objects created by WebRequest.Create can be used for exactly one request. Since there is no "GET and DELETE" method in FTP you need to create another FtpWebRequest with the same configuration and send delete request with that new FtpWebRequest.

Multiple threads uploading files to filezilla ftp server returns error 550 File unavailable

Problem: When i ftp upload only one file at a time, the files are uploaded fine, But when i use multiple Background workers to upload files to ftp server i get exception:
ex {"The remote server returned an error: (550) File unavailable
(e.g., file not found, no access)."} System.Exception
{System.Net.WebException}
And only Some of the files get uploaded. I am pretty sure the file exits at that location, infact in another run the file it was complaining about that does not exist is downloaded but the error shifts on another file.
Code Description:
In below code i am downloading a file from one ftp server and putting it on another. This code is inside a BackgroundsWorker_DoWork Method. Background Workers are being created inside a loop.
void imageDownloadWorker_DoWork(object sender, DoWorkEventArgs e)
{
string[] ftpInfo = (string[])e.Argument;
try
{
///////////////////////////Downloading///////////////////////////////////////
string uri = String.Format("ftp://{0}/{1}/images/{2}", ftpInfo[1], ftpInfo[2], ftpInfo[5]);
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(uri);
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.UseBinary = true;
request.Credentials = new NetworkCredential(ftpInfo[3], ftpInfo[4]);
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Stream ftpStream = response.GetResponseStream();
long cl = response.ContentLength;
int bufferSize = 4096;
int readCount = 0;
byte[] buffer = new byte[bufferSize];
MemoryStream memStream = new MemoryStream();
readCount = ftpStream.Read(buffer, 0, bufferSize);
while (readCount > 0)
{
memStream.Write(buffer, 0, readCount);
readCount = ftpStream.Read(buffer, 0, bufferSize);
}
response.Close();
///////////////////////////Uploading///////////////////////////////////////
string uri1 = String.Format("ftp://{0}/{1}/{2}", "127.0.0.1", string.Empty, ftpInfo[5]);
FtpWebRequest request1 = (FtpWebRequest)WebRequest.Create(uri1);
request1.Credentials = new NetworkCredential("user", "password");
request1.KeepAlive = false;
request1.Method = WebRequestMethods.Ftp.UploadFile;
request1.UseBinary = true;
request1.ContentLength = memStream.Length;
int buffLength = 4096;
byte[] buff = new byte[buffLength];
int contentLen;
// Stream to which the file to be upload is written
Stream strm = request1.GetRequestStream();
memStream.Seek(0, SeekOrigin.Begin);
contentLen = memStream.Read(buff, 0, buffLength);
// Till Stream content ends
while (contentLen != 0)
{
// Write Content from the file stream to the FTP Upload Stream
strm.Write(buff, 0, contentLen);
contentLen = memStream.Read(buff, 0, buffLength);
}
// Close the file stream and the Request Stream
strm.Close();
ftpStream.Close();
memStream.Close();
}
catch(Exception ex)
{
MessageBox.Show("While Downloading File " + ftpInfo[5] + " " + ex.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
e.Result = null;
return;
}
Related Thread
Edit:
In File Zilla Server there is an option General Settings>Perfomance Settings>Number of Threads i have set that to 20 it didnt make any difference.

There maybe nothing wrong with your code. That error is a Permissions error.

Complete stab in the dark, but does the upload target server have a connection per IP limit? If so you may be falling foul of this by exceeding the concurrent connection limit from a single IP address.

FTP download / upload error 504

I'm trying to write a program which will download a few files from and FTP, zip them up then upload them again to the same FTP location.
I have got it to attempt to download a file. If it fails, it will try again.
If NO errors occur, all files download and upload file.
If any errors occur when downloading, it will download them on the re-attempt, but fail then to upload.
I think the problems are down to not correctly closing a connection, but I can't for the life of me figure it out.
Here's my code; I've added where it fails:
Upload:
FileInfo fileInf = new FileInfo("directory" + zip + ".zip");
string uri = "ftp://address" + fileInf.Name;
FtpWebRequest reqFTP2;
reqFTP2 = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://address" + fileInf.Name));
reqFTP2.Credentials = new NetworkCredential("username", "password");
reqFTP2.KeepAlive = true;
reqFTP2.Method = WebRequestMethods.Ftp.UploadFile;
reqFTP2.UseBinary = true;
reqFTP2.ContentLength = fileInf.Length;
int buffLength = 2048;
byte[] buff = new byte[buffLength];
int contentLen;
FileStream fs = fileInf.OpenRead();
try
{
Stream strm = reqFTP2.GetRequestStream(); //FAILS HERE
contentLen = fs.Read(buff, 0, buffLength);
while (contentLen != 0)
{
strm.Write(buff, 0, contentLen);
contentLen = fs.Read(buff, 0, buffLength);
}
strm.Close();
fs.Close();
}
catch (Exception ex)
{
}
Download:
int errorOccured = 0;
while (errorOccured < 1)
{
FileStream outputStream = new FileStream("directory\\" + file, FileMode.Create);
FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://address/" + file));
reqFTP.Credentials = new NetworkCredential("username", "password");
try
{
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
reqFTP.UseBinary = true;
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
long cl = response.ContentLength;
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = ftpStream.Read(buffer, 0, bufferSize);
while (readCount > 0)
{
outputStream.Write(buffer, 0, readCount);
readCount = ftpStream.Read(buffer, 0, bufferSize);
}
ftpStream.Close();
outputStream.Close();
response.Close();
errorOccured++;
}
catch (Exception er)
{
outputStream.Close();
}

The error 504 – Command not implemented for that parameter.
implies that some option you are using in there is not implemented by the target FTP server. I think that your code is resulting in a bizarre request, suggestion would be to look at the FTP chatter that your process creates on the server side. For exmaple, does the server support PASV mode? FTP protocol in ACTV mode (the default behavior) is always a pain because it explicitly causes the client to open a "file receive port" on port 20 and listen. While most servers support PASV mode transfers, it can become a pain if you don't put them in the PASV mode explicitly. So look at the chatter, see if the server is in PASV mode, and if you still have trouble, look at the chatter to see if there are "Extra Spaces" passed on during FTP negotiation. FTP is quite dinky and there can be several pitfalls. :-)

For starters, wrap your streams in using blocks so that they are disposed appropriately.
See MSDN for more details.

How to solve FTP timeouts in C# app

I'm using the following C# code to FTP a ~40MB CSV file from a remote service provider. Around 50% of the time, the download hangs and eventually times out. In my app log, I get a line like:
> Unable to read data from the transport
> connection: A connection attempt
> failed because the connected party did
> not properly respond after a period of
> time, or established connection failed
> because connected host has failed to
> respond.
When I download the file interactively using a graphical client like LeechFTP, the downloads almost never hang, and complete in about 45 seconds. I'm having a hell of a time understanding what's going wrong.
Can anyone suggest how I can instrument this code to get more insight into what's going on, or a better way to download this file? Should I increase the buffer size? By how much? Avoid the buffered writes to disk and try to swallow the whole file in memory? Any advice appreciated!
...
private void CreateDownloadFile()
{
_OutputFile = new FileStream(_SourceFile, FileMode.Create);
}
public string FTPDownloadFile()
{
this.CreateDownloadFile();
myReq = (FtpWebRequest)FtpWebRequest.Create(new Uri(this.DownloadURI));
myReq.Method = WebRequestMethods.Ftp.DownloadFile;
myReq.UseBinary = true;
myReq.Credentials = new NetworkCredential(_ID, _Password);
FtpWebResponse myResp = (FtpWebResponse)myReq.GetResponse();
Stream ftpStream = myResp.GetResponseStream();
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
int bytesRead = 0;
readCount = ftpStream.Read(buffer, 0, bufferSize);
while (readCount > 0)
{
_OutputFile.Write( buffer, 0, readCount );
readCount = ftpStream.Read( buffer, 0, bufferSize );
Console.Write( '.' ); // show progress on the console
bytesRead += readCount;
}
Console.WriteLine();
logger.logActivity( " FTP received " + String.Format( "{0:0,0}", bytesRead ) + " bytes" );
ftpStream.Close();
_OutputFile.Close();
myResp.Close();
return this.GetFTPStatus();
}
public string GetFTPStatus()
{
return ((FtpWebResponse)myReq.GetResponse()).StatusDescription;
}

I tried to use FTPClient as suggested above and got the same timeout error, FTPClient uses FtpWebRequest so I must be missing something but I don't see the point.
After some more research I found that -1 is the value for infinity
For my purpose it is okay to use infinity so I went with that, problem solved.
Here is my code:
//gets file from FTP site.
FtpWebRequest reqFTP;
string fileName = #"c:\downloadDir\localFileName.txt";
FileInfo downloadFile = new FileInfo(fileName);
string uri = "ftp://ftp.myftpsite.com/ftpDir/remoteFileName.txt";
FileStream outputStream = new FileStream(fileName, FileMode.Append);
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
reqFTP.UseBinary = true;
reqFTP.KeepAlive = false;
reqFTP.Timeout = -1;
reqFTP.UsePassive = true;
reqFTP.Credentials = new NetworkCredential("userName", "passWord");
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream ftpStream = response.GetResponseStream();
long cl = response.ContentLength;
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = ftpStream.Read(buffer, 0, bufferSize);
Console.WriteLine("Connected: Downloading File");
while (readCount > 0)
{
outputStream.Write(buffer, 0, readCount);
readCount = ftpStream.Read(buffer, 0, bufferSize);
Console.WriteLine(readCount.ToString());
}
ftpStream.Close();
outputStream.Close();
response.Close();
Console.WriteLine("Downloading Complete");

I suggest you don't use FtpWebRequest for FTP access. FtpWebRequest is the most brain-dead FTP API I have every seen.
Currently I use FtpClient http://www.codeplex.com/ftpclient
I also have had good luck with IndySockets http://www.indyproject.org/index.en.aspx

I haven't dealt with FTP on a code level, but FTP supports resuming. Maybe you could have it automatically try to resume the upload when it times out