FTP Auto Downloader在同时下载三个文件时出现问题. [英] FTP Auto Downloader problem in downloading three files at the same time.
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问题描述
我有一个程序可以从FTP服务器自动下载文件
我有一个通过BackgroundWorker运行的代码，该文件可以下载文件，并且工作正常.
问题是，当我尝试使用同时下载不同文件的三个BackgroundWorkers时，有一个我无法下载的文件(操作有超时)，这三个BackgroundWorkers都无法下载.
当其他BackgroundWorkers中的一个完成下载错误文件(我无法下载的文件)时，我可以下载该文件.(之所以这样做，是因为我有一个循环，当BackgroundWorker无法下载该文件时，我可以这样做.会尝试再次下载)
当有两个BackgroundWorker开始下载时，BackgroundWorker也会发生相同的错误.
是什么导致此错误发生?是在FTP服务器中还是在我的代码中?
实际上，我怀疑FTP服务器是否会导致该错误，因为我看到一个应用程序从FTP服务器(相同的FTP服务器)下载文件，并且它可以同时下载十个文件，但不能自动下载.但我不知道这是否正确.
任何建议表示赞赏.
谢谢. . .
修订:
''这是下载上传报告的后台工作人员
''我使用OLEDB从excel文件中获取数据，因为即使计算机没有Excel，我也希望程序能够运行''安装的应用程序
我正在将数据放入主列表，然后，如果主列表中有一个值，计时器将开始下载过程
I have a program that automatically download a file from FTP Server
I have a code that runs thru BackgroundWorker that download a file and it works fine.
The problem is when I try using three BackgroundWorkers that downloads a different files at the same time, there''s one file that I can''t download (Operation has Time Out) neither the three BackgroundWorkers.
I can download the Error File(the file that I can''t download) when one of the other BackgroundWorkers finish downloading the file.(I can do this because I have a loop that when the BackgroundWorker can''t download the file it will try to download again)
Same error will happen to the BackgroundWorker when theres a two BackgroundWorker that starts its download.
What causes this error to occur? Is it in the FTP Server or my codes?
Actually I doubt that the FTP Server will cause that error because I saw an application that downloads a file from FTP Server(same FTP Server) and it can download ten files at the same time but its not Auto Download. But I don''t know if that''s right.
Any suggestions appreciated.
Thanks. . .
Revision:
''THIS IS THE BACKGROUND WORKER THAT DOWNLOADS THE UPLOAD REPORTS
''I use the OLEDB to get data from an excel file cause I want the program to run even if the computer don''t have an Excel ''Application installed
''I''m putting the data to a Master List then if the Master List has a value a Timer will start the download process
Private Sub bckReport_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bckReport.DoWork
Dim MyConnection As OleDbConnection
Dim DtSet As DataSet
Dim MyCommand As OleDbDataAdapter
Me.Invoke(safeLogs, "Connecting to FTP Server...", "", ftpSite, saveTo)
Dim request As FtpWebRequest = Nothing
Dim response As FtpWebResponse = Nothing
request = DirectCast(WebRequest.Create(ftpSite + Format(Now, "ddMMyyyy")), FtpWebRequest)
request.Method = WebRequestMethods.Ftp.ListDirectory
request.Credentials = New NetworkCredential(username, password)
response = DirectCast(request.GetResponse(), FtpWebResponse)
Dim responseStream As Stream = response.GetResponseStream()
Dim reader As New StreamReader(responseStream)
Dim CrLf As Char() = {vbCr, vbLf}
Dim lines() As String = reader.ReadToEnd().Split(CrLf, StringSplitOptions.RemoveEmptyEntries)
Dim ctr As Integer = 0
For i As Integer = 0 To UBound(lines)
If lines(i).EndsWith(".xls") Then ctr = ctr + 1
Next i
Me.Invoke(safeLogs, "Downloading " & ctr & " Upload Report(s)...", "", ftpSite + Format(Now, "ddMMyyyy") + "/", saveTo)
For i As Integer = 0 To UBound(lines)
TimerReport.Enabled = False
If Not Directory.Exists(saveTo + "tmp\") Then
Directory.CreateDirectory(saveTo + "tmp\")
End If
If Not File.Exists(saveTo + "tmp\" + lines(i)) And lines(i).EndsWith(".xls") Then
Dim outputStream As New FileStream(saveTo + "tmp\" + lines(i), FileMode.Create)
Dim ftpStream As Stream
Try
request = DirectCast(FtpWebRequest.Create(New Uri(ftpSite + Format(Now, "ddMMyyyy") + "/" + lines(i))), FtpWebRequest)
request.Method = WebRequestMethods.Ftp.DownloadFile
request.UseBinary = True
request.Credentials = New NetworkCredential(username, password)
response = DirectCast(request.GetResponse(), FtpWebResponse)
ftpStream = response.GetResponseStream()
Dim bufferSize As Integer = 10000 'size of maximum download
Dim readCount As Integer
Dim buffer As Byte() = New Byte(bufferSize - 1) {}
readCount = ftpStream.Read(buffer, 0, bufferSize)
While readCount > 0
outputStream.Write(buffer, 0, readCount)
readCount = ftpStream.Read(buffer, 0, bufferSize)
End While
outputStream.Close()
MyConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; " & _
"Data Source='" & saveTo + "tmp\" + lines(i) & " '; " & "Extended Properties=""Excel 8.0;HDR=NO;IMEX=1"";")
MyCommand = New OleDbDataAdapter("SELECT * FROM [" + Mid(lines(i), 1, Len(lines(i)) - 4) + "$];", MyConnection)
MyCommand.TableMappings.Add("Table", "Attendence")
DtSet = New DataSet
MyCommand.Fill(DtSet)
Dim safePopulateDatGridView As New PopulateDatGridViewSafe(AddressOf PopulateDatGridView)
Me.Invoke(safePopulateDatGridView, DtSet)
MyConnection.Close()
For j As Integer = 1 To dtgView.RowCount - 1
If dtgView.Item(1, j).Value = "" And dtgView.Item(3, j).Value = "" Then
Exit For
End If
'Job Information | FTP Site | Excel File Location | Image Count
downloadList.Add(dtgView.Item(1, j).Value + "|" + ftpSite + Format(Now, "ddMMyyyy") + "/" + dtgView.Item(3, j).Value + "|" + saveTo + "tmp\" + lines(i) + "|" + dtgView.Item(5, j).Value)
Next j
Catch ex As Exception
Me.Invoke(safeLogs, ex.Message.ToString + " Downloading again...", "Error in Upload Report.", ftpSite + Format(Now, "ddMMyyyy") + "\" + lines(i), saveTo + lines(i))
outputStream.Close()
File.Delete(saveTo + "tmp\" + lines(i))
i = i - 1
End Try
End If
Next i
End Sub
''这是开始下载过程的计时器
"我将数据与主列表分开，将其放入3个列表中，以便每个BackgrounWorker进行处理
''This is the Timer that starts the download process
''I separate the data from a Master List putting it to 3 List each one for each BackgrounWorker to process
Private Sub TimerStart_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerStart.Tick
If downloadList.Count > 0 Then
Dim readyList As ArrayList = New ArrayList
For i As Integer = 0 To downloadList.Count - 1
readyList.Add(downloadList.Item(i))
Next i
For i As Integer = 0 To downloadList.Count - 1
downloadList.Remove(readyList.Item(i))
Next i
For i As Integer = 0 To readyList.Count - 1
If list2.Count < list1.Count And list2.Count < list3.Count Then
list2.Add(readyList.Item(i))
ElseIf list1.Count = list2.Count Then
list1.Add(readyList.Item(i))
Else
list3.Add(readyList.Item(i))
End If
Next i
If Not bckDownloader1.IsBusy Then bckDownloader1.RunWorkerAsync()
If Not bckDownloader2.IsBusy Then bckDownloader2.RunWorkerAsync()
If Not bckDownloader3.IsBusy Then bckDownloader3.RunWorkerAsync()
End If
End Sub
''地勤工人
``我有相同的过程，不同之处在于我访问的变量和函数
''ftp1 = FTP文件站点
''list1 =下载列表
''fileName1 =文件名
''request1 = FtpWebRequest
''response1 = FtpWebResponse
''当此BackgorundWorker启动时，它不会停止从列表进入(在While时，list1.Count> 0)
''BACKGROUNDWORKERS
''I have same process the difference is the variable and function I access
''ftp1 = the FTP file site
''list1 = list of downloads
''fileName1 = filename
''request1 = FtpWebRequest
''response1 = FtpWebResponse
''When this BackgorundWorker starts it will not stop getting in from list (Do While list1.Count > 0)
Private Sub bckDownloader1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bckDownloader1.DoWork
Me.Invoke(safeButtonEnable, 2)
Dim downloaded As Long
Dim elapseTime As New Stopwatch
Dim safeDownloadStatus As New DownloadStatusSafe1(AddressOf DownloadStatus1)
Do While list1.Count > 0
Dim lstArr As Object = Split(list1.Item(0), "|")
Dim saveLocation As String = saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0) + "\"
If Not Directory.Exists(saveTo + Format(Now, "ddMMyyyy") + "\") Then
Directory.CreateDirectory(saveTo + Format(Now, "ddMMyyyy") + "\")
End If
If Not Directory.Exists(saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0)) Then
Directory.CreateDirectory(saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0))
End If
Dim logStr As String
Dim del As String = list1.Item(0)
ftp1 = lstArr(1)
fileName1 = Split(ftp1, "/")(UBound(Split(ftp1, "/")))
If Not (File.Exists(saveLocation + Split(lstArr(2), "\")(UBound(Split(lstArr(2), "\"))))) Then
File.Copy(lstArr(2), saveLocation + Split(lstArr(2), "\")(UBound(Split(lstArr(2), "\"))))
End If
File.Delete(lstArr(2))
If Not (File.Exists(saveLocation + fileName1)) Then
Dim outputStream As New FileStream(saveLocation + fileName1, FileMode.Create)
Dim ftpStream As Stream
Try
downloaded = 0
elapseTime.Reset()
elapseTime.Start()
Me.Invoke(safeLogs, "Downloading " & fileName1, "", ftp1, saveLocation)
Me.Invoke(safeDownloadStatus, fileName1, 0, 0, 0, 2)
Dim FTPfileSize As Long = GetFTPFileSize1(saveLocation)
If FTPfileSize > 0 Then
logStr = lstArr(0) + "," + Format(Now, "ddMMyyyy") + "," + fileName1 + "," + Format(Now, "hh:mm:ss tt").ToString + "," + lstArr(3)
request1 = DirectCast(FtpWebRequest.Create(New Uri(ftp1)), FtpWebRequest)
request1.Method = WebRequestMethods.Ftp.DownloadFile
request1.UseBinary = True
request1.Credentials = New NetworkCredential(username, password)
response1 = DirectCast(request1.GetResponse(), FtpWebResponse)
ftpStream = response1.GetResponseStream()
Dim bufferSize As Integer = 10000 'size of maximum download
Dim readCount As Integer
Dim buffer As Byte() = New Byte(bufferSize - 1) {}
readCount = ftpStream.Read(buffer, 0, bufferSize)
While readCount > 0
If bckDownloader1.CancellationPending Then 'If user abort download
Me.Invoke(safeButtonEnable, 1)
outputStream.Close()
File.Delete(saveLocation + fileName1)
Exit Do
End If
downloaded = downloaded + readCount
outputStream.Write(buffer, 0, readCount)
readCount = ftpStream.Read(buffer, 0, bufferSize)
Me.Invoke(safeDownloadStatus, fileName1, elapseTime.ElapsedMilliseconds, downloaded, FTPfileSize, 1)
End While
Me.Invoke(safeLogs, fileName1 + " has been downloaded...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
logStr = logStr + "," + Format(Now, "hh:mm:ss tt").ToString
elapseTime.Stop()
list1.Remove(del)
Else
outputStream.Close()
File.Delete(saveLocation + fileName1)
End If
Catch ex As Exception
Try
Me.Invoke(safeLogs, ex.Message.ToString + " Downloading again...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
outputStream.Close()
File.Delete(saveLocation + fileName1)
Catch ex1 As Exception
End Try
End Try
Else
Me.Invoke(safeLogs, fileName1 + " has been downloaded...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
logStr = fileName1 + "already exist in folder directory " + saveLocation
elapseTime.Stop()
list1.Remove(del)
End If
Loop
Me.Invoke(safeDownloadStatus, "", 0, 0, 0, 3)
End Sub
推荐答案
;"，MyConnection) MyCommand.TableMappings.Add(" ，" 出勤" ) DtSet = 新建数据集 MyCommand.Fill(DtSet) Dim safePopulateDatGridView As 新建 PopulateDatGridViewSafe( AddressOf PopulateDatGridView) 我 .Invoke(safePopulateDatGridView，DtSet) MyConnection.Close() 对于 j As 整数 = 1 收件人 dtgView.RowCount- 1 如果 dtgView.Item( 1 ，j).值= " 和 dtgView.Item( 3 ，j).值= " 然后 退出 用于 结束 如果 ' 工作信息| FTP站点| Excel文件位置|图像计数 downloadList.Add(dtgView.Item( 1 ，j).Value + " + ftpSite + Format(现在，" )+ " + dtgView.Item( 3 ，j).值+ " + saveTo + " + lines(i)+ " + dtgView.Item( 5 ，j).Value) 下一步 j 捕获，例如 As 异常 我 .Invoke(safeLogs，例如Message.ToString + " 再次下载..."， 上传报告中的错误."，ftpSite +格式(现在，" )+ " \" +行(i)，saveTo +行(i)) outputStream.Close() File.Delete(saveTo + " + lines(i)) i = i- 1 结束 尝试 结束 如果 下一个我 结束 子
;", MyConnection) MyCommand.TableMappings.Add("Table", "Attendence") DtSet = New DataSet MyCommand.Fill(DtSet) Dim safePopulateDatGridView As New PopulateDatGridViewSafe(AddressOf PopulateDatGridView) Me.Invoke(safePopulateDatGridView, DtSet) MyConnection.Close() For j As Integer = 1 To dtgView.RowCount - 1 If dtgView.Item(1, j).Value = "" And dtgView.Item(3, j).Value = "" Then Exit For End If 'Job Information | FTP Site | Excel File Location | Image Count downloadList.Add(dtgView.Item(1, j).Value + "|" + ftpSite + Format(Now, "ddMMyyyy") + "/" + dtgView.Item(3, j).Value + "|" + saveTo + "tmp\" + lines(i) + "|" + dtgView.Item(5, j).Value) Next j Catch ex As Exception Me.Invoke(safeLogs, ex.Message.ToString + " Downloading again...", "Error in Upload Report.", ftpSite + Format(Now, "ddMMyyyy") + "\" + lines(i), saveTo + lines(i)) outputStream.Close() File.Delete(saveTo + "tmp\" + lines(i)) i = i - 1 End Try End If Next i End Sub
''这是开始下载过程的计时器
"我将数据与主列表分开，将其放入3个列表中，以便每个BackgrounWorker进行处理
''This is the Timer that starts the download process
''I separate the data from a Master List putting it to 3 List each one for each BackgrounWorker to process
Private Sub TimerStart_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerStart.Tick
If downloadList.Count > 0 Then
Dim readyList As ArrayList = New ArrayList
For i As Integer = 0 To downloadList.Count - 1
readyList.Add(downloadList.Item(i))
Next i
For i As Integer = 0 To downloadList.Count - 1
downloadList.Remove(readyList.Item(i))
Next i
For i As Integer = 0 To readyList.Count - 1
If list2.Count < list1.Count And list2.Count < list3.Count Then
list2.Add(readyList.Item(i))
ElseIf list1.Count = list2.Count Then
list1.Add(readyList.Item(i))
Else
list3.Add(readyList.Item(i))
End If
Next i
If Not bckDownloader1.IsBusy Then bckDownloader1.RunWorkerAsync()
If Not bckDownloader2.IsBusy Then bckDownloader2.RunWorkerAsync()
If Not bckDownloader3.IsBusy Then bckDownloader3.RunWorkerAsync()
End If
End Sub
''地勤工人
``我有相同的过程，不同之处在于我访问的变量和函数
''ftp1 = FTP文件站点
''list1 =下载列表
''fileName1 =文件名
''request1 = FtpWebRequest
''response1 = FtpWebResponse
''当此BackgorundWorker启动时，它不会停止从列表进入(在While时，list1.Count> 0)
''BACKGROUNDWORKERS
''I have same process the difference is the variable and function I access
''ftp1 = the FTP file site
''list1 = list of downloads
''fileName1 = filename
''request1 = FtpWebRequest
''response1 = FtpWebResponse
''When this BackgorundWorker starts it will not stop getting in from list (Do While list1.Count > 0)
Private Sub bckDownloader1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bckDownloader1.DoWork
Me.Invoke(safeButtonEnable, 2)
Dim downloaded As Long
Dim elapseTime As New Stopwatch
Dim safeDownloadStatus As New DownloadStatusSafe1(AddressOf DownloadStatus1)
Do While list1.Count > 0
Dim lstArr As Object = Split(list1.Item(0), "|")
Dim saveLocation As String = saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0) + "\"
If Not Directory.Exists(saveTo + Format(Now, "ddMMyyyy") + "\") Then
Directory.CreateDirectory(saveTo + Format(Now, "ddMMyyyy") + "\")
End If
If Not Directory.Exists(saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0)) Then
Directory.CreateDirectory(saveTo + Format(Now, "ddMMyyyy") + "\" + lstArr(0))
End If
Dim logStr As String
Dim del As String = list1.Item(0)
ftp1 = lstArr(1)
fileName1 = Split(ftp1, "/")(UBound(Split(ftp1, "/")))
If Not (File.Exists(saveLocation + Split(lstArr(2), "\")(UBound(Split(lstArr(2), "\"))))) Then
File.Copy(lstArr(2), saveLocation + Split(lstArr(2), "\")(UBound(Split(lstArr(2), "\"))))
End If
File.Delete(lstArr(2))
If Not (File.Exists(saveLocation + fileName1)) Then
Dim outputStream As New FileStream(saveLocation + fileName1, FileMode.Create)
Dim ftpStream As Stream
Try
downloaded = 0
elapseTime.Reset()
elapseTime.Start()
Me.Invoke(safeLogs, "Downloading " & fileName1, "", ftp1, saveLocation)
Me.Invoke(safeDownloadStatus, fileName1, 0, 0, 0, 2)
Dim FTPfileSize As Long = GetFTPFileSize1(saveLocation)
If FTPfileSize > 0 Then
logStr = lstArr(0) + "," + Format(Now, "ddMMyyyy") + "," + fileName1 + "," + Format(Now, "hh:mm:ss tt").ToString + "," + lstArr(3)
request1 = DirectCast(FtpWebRequest.Create(New Uri(ftp1)), FtpWebRequest)
request1.Method = WebRequestMethods.Ftp.DownloadFile
request1.UseBinary = True
request1.Credentials = New NetworkCredential(username, password)
response1 = DirectCast(request1.GetResponse(), FtpWebResponse)
ftpStream = response1.GetResponseStream()
Dim bufferSize As Integer = 10000 'size of maximum download
Dim readCount As Integer
Dim buffer As Byte() = New Byte(bufferSize - 1) {}
readCount = ftpStream.Read(buffer, 0, bufferSize)
While readCount > 0
If bckDownloader1.CancellationPending Then 'If user abort download
Me.Invoke(safeButtonEnable, 1)
outputStream.Close()
File.Delete(saveLocation + fileName1)
Exit Do
End If
downloaded = downloaded + readCount
outputStream.Write(buffer, 0, readCount)
readCount = ftpStream.Read(buffer, 0, bufferSize)
Me.Invoke(safeDownloadStatus, fileName1, elapseTime.ElapsedMilliseconds, downloaded, FTPfileSize, 1)
End While
Me.Invoke(safeLogs, fileName1 + " has been downloaded...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
logStr = logStr + "," + Format(Now, "hh:mm:ss tt").ToString
elapseTime.Stop()
list1.Remove(del)
Else
outputStream.Close()
File.Delete(saveLocation + fileName1)
End If
Catch ex As Exception
Try
Me.Invoke(safeLogs, ex.Message.ToString + " Downloading again...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
outputStream.Close()
File.Delete(saveLocation + fileName1)
Catch ex1 As Exception
End Try
End Try
Else
Me.Invoke(safeLogs, fileName1 + " has been downloaded...", "Panel(1) Downloading File.", ftp1, saveLocation + fileName1)
logStr = fileName1 + "already exist in folder directory " + saveLocation
elapseTime.Stop()
list1.Remove(del)
End If
Loop
Me.Invoke(safeDownloadStatus, "", 0, 0, 0, 3)
End Sub
BackgroundWorker runs on separate thread.
If one affects the others, my best guess is that your code isn''t threadsafe.
My suggestion:
1. Make all global variables and objects local to your code.
2. Synchronize access to vars and objects that cannot be localized.
The idea is to make your code independent and isolated from external changes.
祝你好运.
Post your code if you want better help.
BackgroundWorker runs on separate thread.
If one affects the others, my best guess is that your code isn''t threadsafe.
My suggestion:
1. Make all global variables and objects local to your code.
2. Synchronize access to vars and objects that cannot be localized.
The idea is to make your code independent and isolated from external changes.
Good luck.
Post your code if you want better help.
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