Check if FTP folder exists & if not then create it

Question

I need a function to complete the following tasks:

1. Check if a folder exists (via its name) - if not then, create it.
2. Upload a file into the directory.

I tried with the following code, but it does not seem to check and create the directory:

Dim request As System.Net.FtpWebRequest = DirectCast(System.Net.FtpWebRequest.Create("HOST"), System.Net.FtpWebRequest)
request.Credentials = New System.Net.NetworkCredential("uase", "pass")
request.Method = System.Net.WebRequestMethods.Ftp.UploadFile

Dim file() As Byte = System.IO.File.ReadAllBytes("C:\Users\Nini\Desktop\10ebd0d.png")
Dim str As System.IO.Stream = request.GetRequestStream()
str.Write(file, 0, file.Length)
str.Close()
str.Dispose()

Answer 1

1.Check if a folder exists (via its name) - if not then, create it.

I'll admit that this is not the most robust or elegant solution but I was OK with something 'quick and dirty' for the occasional one-off need that I have for this.

    Dim request As FtpWebRequest = FtpWebRequest.Create("ftp://myftp/parentfolder")
    Dim creds As NetworkCredential = New NetworkCredential("user", "pwd")
    request.Credentials = creds

    Dim resp As FtpWebResponse = Nothing
    request.Method = WebRequestMethods.Ftp.ListDirectoryDetails
    request.KeepAlive = True
        Using resp
            resp = request.GetResponse()
            Dim sr As StreamReader = New StreamReader(resp.GetResponseStream(), System.Text.Encoding.ASCII)
            Dim s As String = sr.ReadToEnd()
        If Not s.Contains("newfolder") Then

            request = FtpWebRequest.Create("ftp://myftp/parentfolder/newfolder")
            request.Credentials = creds
            request.Method = WebRequestMethods.Ftp.MakeDirectory
            resp = request.GetResponse()
            Console.WriteLine(resp.StatusCode & "Created")
        Else
            Console.WriteLine("Directory already exists")
        End If
            Console.ReadLine()
        End Using

Answer 2

You could use the FTPClient library for .NET

I've did an helper Class to manage the library (but is easy as is provided there is no need to use an helper Class)

The methods that you're interested to are DirectoryExists, CreateDirectory, and UploadFile

This is an example usage:

Public Class Form1

    Private WithEvents UploadClient As New System.Net.WebClient()
    Private WithEvents DownloadClient As New System.Net.WebClient()

    Private ftp As New FTP("ftpsite", "username", "password")

    Private Sub Test() Handles MyBase.Shown

        ftp.Connect()
        ftp.CreateDirectory("/DirectoryName", True)
        ftp.UploadFile(UploadClient, "C:\File.txt", "/DirectoryName/NewFile.txt", False)
        ftp.DownloadFile(DownloadClient, "/DirectoryName/NewFile.txt", "c:\DownloadedFile.txt", True)

    End Sub

    Private Sub Client_UploadProgress(sender As System.Net.WebClient, e As System.Net.UploadProgressChangedEventArgs) _
    Handles UploadClient.UploadProgressChanged

        Label_Upload.Text = e.ProgressPercentage & "%"

    End Sub

    Private Sub Client_UploadCompleted(sender As System.Net.WebClient, e As System.Net.UploadFileCompletedEventArgs) _
    Handles UploadClient.UploadFileCompleted

        Label_UploadCompleted.Text = e.Result.ToString

    End Sub

    Private Sub Client_DownloadProgress(sender As System.Net.WebClient, e As System.Net.DownloadProgressChangedEventArgs) _
    Handles DownloadClient.DownloadProgressChanged

        Label_Download.Text = e.ProgressPercentage & "%"

    End Sub

    Private Sub Client_DownloadCompleted(sender As System.Net.WebClient, e As System.ComponentModel.AsyncCompletedEventArgs) _
     Handles DownloadClient.DownloadFileCompleted

        Label_DownloadCompleted.Text = "Done!"

    End Sub

End Class

The Helper Class:

Imports System.Net
Imports System.Net.FtpClient
Imports System.Net.FtpClient.Extensions

#Region " FTPClient Helper "

' [ FTPClient Helper ]
'
' // By Elektro


Public Class FTP

#Region " Variables "

    Private conn As New FtpClient

    ''' <summary>
    ''' The FTP site.
    ''' </summary>
    Private Property host As String = String.Empty

    ''' <summary>
    ''' The user name.
    ''' </summary>
    Private Property user As String = String.Empty

    ''' <summary>
    ''' The user password.
    ''' </summary>
    Private Property pass As String = String.Empty

    ' Friend m_reset As New ManualResetEvent(False) ' Use it for CallBacks

#End Region

#Region " Constructor "

    ''' <summary>
    ''' .
    ''' </summary>
    ''' <param name="host">Indicates the ftp site.</param>
    ''' <param name="user">Indicates the username.</param>
    ''' <param name="pass">Indicates the password.</param>
    Public Sub New(ByVal host As String,
                   ByVal user As String,
                   ByVal pass As String)

        If Not host.ToLower.StartsWith("ftp://") Then
            Me.host = "ftp://" & host
        Else
            Me.host = host
        End If

        If Me.host.Last = "/" Then
            Me.host = Me.host.Remove(Me.host.Length - 1)
        End If

        Me.user = user
        Me.pass = pass

        With conn
            .Host = If(host.Last = "/", host.Remove(host.Length - 1), host)
            .Credentials = New NetworkCredential(Me.user, Me.pass)
        End With

    End Sub

#End Region

#Region " Public Methods "

    ''' <summary>
    ''' Connects to server.
    ''' </summary>
    Public Sub Connect()
        conn.Connect()
    End Sub

    ''' <summary>
    ''' Disconnects from server.
    ''' </summary>
    Public Sub Disconnect()
        conn.Disconnect()
    End Sub

    ''' <summary>
    ''' Creates a directory on server.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="force">Try to force all non-existant pieces of the path to be created.</param>
    Public Sub CreateDirectory(ByVal directorypath As String, ByVal force As Boolean)
        conn.CreateDirectory(directorypath, force)
    End Sub

    ''' <summary>
    ''' Creates a directory on server.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="force">Try to force all non-existant pieces of the path to be created.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Sub DeleteDirectory(ByVal directorypath As String,
                               ByVal force As Boolean,
                               Optional ByVal FtpListOption As FtpListOption =
                               FtpListOption.AllFiles Or FtpListOption.ForceList)

        ' Remove the directory and all objects beneath it. The last parameter
        ' forces System.Net.FtpClient to use LIST -a for getting a list of objects
        ' beneath the specified directory.
        conn.DeleteDirectory(directorypath, force, FtpListOption)

    End Sub

    ''' <summary>
    ''' Deletes a file on server.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Sub DeleteFile(ByVal filepath As String)
        conn.DeleteFile(filepath)
    End Sub

    ''' <summary>
    ''' Checks if a directory exist on server.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    Public Function DirectoryExists(ByVal directorypath As String) As Boolean
        Return conn.DirectoryExists(directorypath)
    End Function

    ''' <summary>
    ''' Executes a command on server.
    ''' </summary>
    ''' <param name="command">Indicates the command to execute on the server.</param>
    ''' <returns>Returns an object containing the server reply information.</returns>
    Public Function Execute(ByVal command As String) As FtpReply
        Return (InlineAssignHelper(New FtpReply, conn.Execute(command)))
    End Function

    ''' <summary>
    ''' Tries to execute a command on server.
    ''' </summary>
    ''' <param name="command">Indicates the command to execute on the server.</param>
    ''' <returns>Returns TRUE if command execution successfull, otherwise returns False.</returns>
    Public Function TryExecute(ByVal command As String) As Boolean
        Dim reply As FtpReply = Nothing
        Return (InlineAssignHelper(reply, conn.Execute(command))).Success
    End Function

    ''' <summary>
    ''' Checks if a file exist on server.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Function FileExists(ByVal filepath As String,
                               Optional ByVal FtpListOption As FtpListOption =
                               FtpListOption.AllFiles Or FtpListOption.ForceList) As Boolean

        ' The last parameter forces System.Net.FtpClient to use LIST -a 
        ' for getting a list of objects in the parent directory.
        Return conn.FileExists(filepath, FtpListOption)

    End Function

    ''' <summary>
    ''' Retrieves a checksum of the given file
    ''' using a checksumming method that the server supports, if any.
    ''' The algorithm used goes in this order: 
    ''' 1. HASH command (server preferred algorithm).
    ''' 2. MD5 / XMD5 commands 
    ''' 3. XSHA1 command 
    ''' 4. XSHA256 command 
    ''' 5. XSHA512 command
    ''' 6. XCRC command
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function GetChecksum(ByVal filepath As String) As FtpHash
        Return conn.GetChecksum(filepath)
    End Function

    ''' <summary>
    ''' Gets the checksum of file on server and compare it with the checksum of local file.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    ''' <param name="localfilepath">Indicates the local disk file path.</param>
    ''' <param name="algorithm">Indicates the algorithm that should be used to verify checksums.</param>
    ''' <returns>Returns TRUE if both checksums are equal, otherwise returns False.</returns>
    Public Function VerifyChecksum(ByVal filepath As String,
                                   ByVal localfilepath As String,
                                   ByVal algorithm As FtpHashAlgorithm) As Boolean

        Dim hash As FtpHash = Nothing

        hash = conn.GetChecksum(filepath)
        ' Make sure it returned a, to the best of our knowledge, valid hash object. 
        ' The commands for retrieving checksums are
        ' non-standard extensions to the protocol so we have to
        ' presume that the response was in a format understood by
        ' System.Net.FtpClient and parsed correctly.
        '
        ' In addition, there is no built-in support for verifying CRC hashes. 
        ' You will need to write you own or use a third-party solution.
        If hash.IsValid AndAlso hash.Algorithm <> algorithm Then
            Return hash.Verify(localfilepath)
        Else
            Return Nothing
        End If

    End Function

    ''' <summary>
    ''' Gets the size of file.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function GetFileSize(ByVal filepath As String) As Long
        Return conn.GetFileSize(filepath)
    End Function

    ''' <summary>
    ''' Gets the currently HASH algorithm used for the HASH command on server.
    ''' </summary>
    Public Function GetHashAlgorithm() As FtpHashAlgorithm
        Return conn.GetHashAlgorithm()
    End Function

    ''' <summary>
    ''' Gets the modified time of file.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function GetModifiedTime(ByVal filepath As String) As Date
        Return conn.GetModifiedTime(filepath)
    End Function

    ''' <summary>
    ''' Returns a file/directory listing using the NLST command.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp file path.</param>
    Public Function GetNameListing(ByVal directorypath As String) As String()
        Return conn.GetNameListing(directorypath)
    End Function

    ''' <summary>
    ''' Gets the current working directory on server.
    ''' </summary>
    Public Function GetWorkingDirectory() As String
        Return conn.GetWorkingDirectory()
    End Function

    ''' <summary>
    ''' Opens the specified file to be appended to...
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function OpenAppend(ByVal filepath As String) As IO.Stream
        Return conn.OpenAppend(filepath)
    End Function

    ''' <summary>
    ''' Opens the specified file for reading.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function OpenRead(ByVal filepath As String) As IO.Stream
        Return conn.OpenRead(filepath)
    End Function

    ''' <summary>
    ''' Opens the specified file for writing.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    Public Function OpenWrite(ByVal filepath As String) As IO.Stream
        Return conn.OpenWrite(filepath)
    End Function

    ''' <summary>
    ''' Rename a file on the server.
    ''' </summary>
    ''' <param name="filepath">Indicates the ftp file path.</param>
    ''' <param name="newfilepath">Indicates the new ftp file path.</param>
    Public Sub RenameFile(ByVal filepath As String, ByVal newfilepath As String)
        If conn.FileExists(filepath) Then
            conn.Rename(filepath, newfilepath)
        Else
            Throw New Exception(filepath & " File does not exist on server.")
        End If
    End Sub

    ''' <summary>
    ''' Rename a directory on the server.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp file path.</param>
    ''' <param name="newdirectorypath">Indicates the new ftp file path.</param>
    Public Sub RenameDirectory(ByVal directorypath As String, ByVal newdirectorypath As String)
        If conn.DirectoryExists(directorypath) Then
            conn.Rename(directorypath, newdirectorypath)
        Else
            Throw New Exception(directorypath & " Directory does not exist on server.")
        End If
    End Sub

    ''' <summary>
    ''' Tells the server wich hash algorithm to use for the HASH command.
    ''' </summary>
    ''' <param name="algorithm">Indicates the HASH algorithm.</param>
    Public Function SetHashAlgorithm(ByVal algorithm As FtpHashAlgorithm) As Boolean
        If conn.HashAlgorithms.HasFlag(algorithm) Then
            conn.SetHashAlgorithm(algorithm)
            Return True
        Else
            Return False
        End If
    End Function

    ''' <summary>
    ''' Sets the working directory on the server.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    Public Sub SetWorkingDirectory(ByVal directorypath As String)
        conn.SetWorkingDirectory(directorypath)
    End Sub

    ''' <summary>
    ''' Gets a directory list on the specified path.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Function GetDirectories(ByVal directorypath As String,
                                   Optional ByVal FtpListOption As FtpListOption =
                                   FtpListOption.AllFiles) As FtpListItem()

        Return conn.GetListing(directorypath, FtpListOption).
               Where(Function(item) item.Type = FtpFileSystemObjectType.Directory)

    End Function

    ''' <summary>
    ''' Gets a file list on the specified path.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Function GetFiles(ByVal directorypath As String,
                             Optional ByVal FtpListOption As FtpListOption =
                             FtpListOption.AllFiles) As FtpListItem()

        Return conn.GetListing(directorypath, FtpListOption).
               Where(Function(item) item.Type = FtpFileSystemObjectType.File)

    End Function

    ''' <summary>
    ''' Gets a link list on the specified path.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Function GetLinks(ByVal directorypath As String,
                             Optional ByVal FtpListOption As FtpListOption =
                             FtpListOption.AllFiles) As FtpListItem()

        Return conn.GetListing(directorypath, FtpListOption).
               Where(Function(item) item.Type = FtpFileSystemObjectType.Link)

    End Function

    ''' <summary>
    ''' Gets a file/folder list on the specified path.
    ''' </summary>
    ''' <param name="directorypath">Indicates the ftp directory path.</param>
    ''' <param name="FtpListOption">Options that dictate how a list is performed ans what information is gathered.</param>
    Public Function GetListing(ByVal directorypath As String,
                               Optional ByVal FtpListOption As FtpListOption =
                               FtpListOption.AllFiles) As FtpListItem()

        Return conn.GetListing(directorypath, FtpListOption)

    End Function

    ''' <summary>
    ''' Log to a console window
    ''' </summary>
    Public Sub LogToConsole()
        FtpTrace.AddListener(New ConsoleTraceListener())
        ' now use System.Net.FtpCLient as usual and the server transactions
        ' will be written to the Console window.
    End Sub

    ''' <summary>
    ''' Log to a text file
    ''' </summary>
    ''' <param name="filepath">Indicates the file where to save the log.</param>
    Public Sub LogToFile(ByVal filepath As String)
        FtpTrace.AddListener(New TextWriterTraceListener(filepath))
        ' now use System.Net.FtpCLient as usual and the server transactions
        ' will be written to the specified log file.
    End Sub

    ''' <summary>
    ''' Uploads a file to FTP.
    ''' </summary>
    ''' <param name="UploadClient">Indicates the WebClient object to upload the file.</param>
    ''' <param name="filepath">Indicates the ftp fle path.</param>
    ''' <param name="localfilepath">Specifies the local path where to save the downloaded file.</param>
    ''' <param name="Asynchronous">Indicates whether the download should be an Asynchronous operation, 
    ''' to raise WebClient events.</param>
    Public Sub UploadFile(ByRef UploadClient As WebClient,
                          ByVal localfilepath As String,
                          Optional ByVal filepath As String = Nothing,
                          Optional ByVal Asynchronous As Boolean = False)

        If filepath Is Nothing Then
            filepath = Me.host & "/" & New IO.FileInfo(localfilepath).Name
        ElseIf filepath.StartsWith("/") Then
            filepath = Me.host & filepath
        Else
            filepath = Me.host & "/" & filepath
        End If

        With UploadClient
            .Credentials = New NetworkCredential(Me.user, Me.pass)
            If Asynchronous Then
                .UploadFileAsync(New Uri(filepath), "STOR", localfilepath)
            Else
                .UploadFile(New Uri(filepath), "STOR", localfilepath)
            End If
        End With

    End Sub

    ''' <summary>
    ''' Downloads a file from FTP.
    ''' </summary>
    ''' <param name="DownloadClient">Indicates the WebClient object to download the file.</param>
    ''' <param name="filepath">Indicates the ftp fle path.</param>
    ''' <param name="localfilepath">Specifies the local path where to save the downloaded file.</param>
    ''' <param name="Asynchronous">Indicates whether the download should be an Asynchronous operation, 
    ''' to raise WebClient events.</param>
    Public Sub DownloadFile(ByRef DownloadClient As WebClient,
                            ByVal filepath As String,
                            ByVal localfilepath As String,
                            Optional ByVal Asynchronous As Boolean = False)

        If filepath.StartsWith("/") Then
            filepath = Me.host & filepath
        Else
            filepath = Me.host & "/" & filepath
        End If

        With DownloadClient
            .Credentials = New NetworkCredential(Me.user, Me.pass)
            If Asynchronous Then
                .DownloadFileAsync(New Uri(filepath), localfilepath)
            Else
                .DownloadFile(New Uri(filepath), localfilepath)
            End If
        End With

    End Sub

#End Region

#Region " Miscellaneous methods "

    Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, value As T) As T
        target = value
        Return value
    End Function

#End Region

End Class

#End Region