vb.net - los - Usar FTP para descargar cada archivo*MIENTRAS*obtener la lista de archivos

donde se guardan los archivos descargados de filezilla

Question

Necesitamos obtener aproximadamente 100 archivos muy pequeños de un servidor FTP remoto usando vb.net. Nuestra empresa no nos permitirá comprar (o instalar) bibliotecas de ftp de terceros ... por lo que nos vemos obligados a utilizar algo como FtpWebRequest. (¿O hay una mejor opción gratuita que ya forma parte de Visual Studio?)

Este método funciona, pero es MUY lento. (Supongo que debido a la constante entrada / salida).

Log in with user name and password. Get a file-list from the remote server. Log out Use that file-list to get each file separtely: Log in, get the file, log out. Log in 99 more times, get each file, log out each time.

En cambio, probablemente deberíamos estar haciendo esto, pero nunca funciona:

Log in with user name and password. ONCE. Get a list of filenames. Download each file. Log out ONCE.

Encontramos innumerables ejemplos en línea de "obtener una lista de archivos FTP" y más tarde "cómo descargar 1 archivo con FTP" ... pero nunca vemos "obtener CADA nombre de archivo y descargarlo AHORA".

Dim fwr As Net.FtpWebRequest = Net.FtpWebRequest.Create(ftpSite) fwr.Credentials = New NetworkCredential(userName, password) fwr.KeepAlive = True fwr.Method = WebRequestMethods.Ftp.ListDirectory Dim sr As IO.StreamReader = Nothing Try sr = New IO.StreamReader(fwr.GetResponse().GetResponseStream()) Do Until (sr.EndOfStream()) fileName = sr.ReadLine() fwr.Method = WebRequestMethods.Ftp.DownloadFile output = "" Dim sr2 As IO.StreamReader = Nothing Try sr2 = New IO.StreamReader(fwr.GetResponse().GetResponseStream()) output = sr2.ReadToEnd() Catch ex As Exception End Try If (Not sr2 Is Nothing) Then sr2.Close() : sr2 = Nothing Call MsgBox("Got " & fileName & LF & output) Loop Catch ex As Exception End Try If (Not sr Is Nothing) Then sr.Close() : sr = Nothing If (Not fwr Is Nothing) Then fwr = Nothing

Answer 1

Algo que acabo de armar, la parte importante es fwr.Proxy = Nothing, de lo contrario, intenta obtener automáticamente la configuración del proxy, lo que provoca enormes retrasos, por lo que al configurarlo en nada lo obliga a no usar uno.

Si está utilizando un proxy, obviamente, debe configurarlo a un proxy real.

Dim fwr As Net.FtpWebRequest = Net.FtpWebRequest.Create(ftpAddress)
fwr.Credentials = New NetworkCredential(userName, password)
fwr.KeepAlive = True
fwr.Method = WebRequestMethods.Ftp.ListDirectory
fwr.Proxy = Nothing

Try
    Dim sr As New IO.StreamReader(fwr.GetResponse().GetResponseStream())
    Dim lst = sr.ReadToEnd().Split(vbNewLine)
    For Each file As String In lst
        file = file.Trim() ''remove any whitespace
        If file = ".." OrElse file = "." Then Continue For
        Dim fwr2 As Net.FtpWebRequest = Net.FtpWebRequest.Create(ftpAddress & file)
        fwr2.Credentials = fwr.Credentials
        fwr2.KeepAlive = True
        fwr2.Method = WebRequestMethods.Ftp.DownloadFile
        fwr2.Proxy = Nothing

        Dim fileSR As New IO.StreamReader(fwr2.GetResponse().GetResponseStream())
        Dim fileData = fileSR.ReadToEnd()
        fileSR.Close()
    Next

    sr.Close()
Catch ex As Exception
End Try

Sé que es un poco tarde pero espero que ayude

Answer 2

Eche un vistazo a mi clase de FTP, podría ser exactamente lo que necesita.

Public Class FTP
        ''-------------------------[BroCode]--------------------------
        ''----------------------------FTP-----------------------------
        Private _credentials As System.Net.NetworkCredential
        Sub New(ByVal _FTPUser As String, ByVal _FTPPass As String)
            setCredentials(_FTPUser, _FTPPass)
        End Sub
        Public Sub UploadFile(ByVal _FileName As String, ByVal _UploadPath As String)
            Dim _FileInfo As New System.IO.FileInfo(_FileName)
            Dim _FtpWebRequest As System.Net.FtpWebRequest = CType(System.Net.FtpWebRequest.Create(New Uri(_UploadPath)), System.Net.FtpWebRequest)
            _FtpWebRequest.Credentials = _credentials
            _FtpWebRequest.KeepAlive = False
            _FtpWebRequest.Timeout = 20000
            _FtpWebRequest.Method = System.Net.WebRequestMethods.Ftp.UploadFile
            _FtpWebRequest.UseBinary = True
            _FtpWebRequest.ContentLength = _FileInfo.Length
            Dim buffLength As Integer = 2048
            Dim buff(buffLength - 1) As Byte
            Dim _FileStream As System.IO.FileStream = _FileInfo.OpenRead()
            Try
                Dim _Stream As System.IO.Stream = _FtpWebRequest.GetRequestStream()
                Dim contentLen As Integer = _FileStream.Read(buff, 0, buffLength)
                Do While contentLen <> 0
                    _Stream.Write(buff, 0, contentLen)
                    contentLen = _FileStream.Read(buff, 0, buffLength)
                Loop
                _Stream.Close()
                _Stream.Dispose()
                _FileStream.Close()
                _FileStream.Dispose()
            Catch ex As Exception
                MessageBox.Show(ex.Message, "Upload Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End Sub
        Public Sub DownloadFile(ByVal _FileName As String, ByVal _ftpDownloadPath As String)
            Try
                Dim _request As System.Net.FtpWebRequest = System.Net.WebRequest.Create(_ftpDownloadPath)
                _request.KeepAlive = False
                _request.Method = System.Net.WebRequestMethods.Ftp.DownloadFile
                _request.Credentials = _credentials
                Dim _response As System.Net.FtpWebResponse = _request.GetResponse()
                Dim responseStream As System.IO.Stream = _response.GetResponseStream()
                Dim fs As New System.IO.FileStream(_FileName, System.IO.FileMode.Create)
                responseStream.CopyTo(fs)
                responseStream.Close()
                _response.Close()
            Catch ex As Exception
                MessageBox.Show(ex.Message, "Download Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End Sub
        Public Function GetDirectory(ByVal _ftpPath As String) As List(Of String)
            Dim ret As New List(Of String)
            Try
                Dim _request As System.Net.FtpWebRequest = System.Net.WebRequest.Create(_ftpPath)
                _request.KeepAlive = False
                _request.Method = System.Net.WebRequestMethods.Ftp.ListDirectoryDetails
                _request.Credentials = _credentials
                Dim _response As System.Net.FtpWebResponse = _request.GetResponse()
                Dim responseStream As System.IO.Stream = _response.GetResponseStream()
                Dim _reader As System.IO.StreamReader = New System.IO.StreamReader(responseStream)
                Dim FileData As String = _reader.ReadToEnd
                Dim Lines() As String = FileData.Split(New String() {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries)
                For Each l As String In Lines
                    ret.Add(l)
                Next
                _reader.Close()
                _response.Close()
            Catch ex As Exception
                MessageBox.Show(ex.Message, "Directory Fetch Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
            Return ret
        End Function

        Private Sub setCredentials(ByVal _FTPUser As String, ByVal _FTPPass As String)
            _credentials = New System.Net.NetworkCredential(_FTPUser, _FTPPass)
        End Sub
    End Class

Para inicializar:

Dim ftp As New FORM.FTP("username", "password")

ftp.UploadFile("c:/file.jpeg", "ftp://domain/file.jpeg")

ftp.DownloadFile("c:/file.jpeg", "ftp://ftp://domain/file.jpeg")

Dim directory As List(Of String) = ftp.GetDirectory("ftp://ftp.domain.net/")
        ListBox1.Items.Clear()
        For Each item As String In directory
            ListBox1.Items.Add(item)
        Next