I am trying to parse a uploaded txt file. I need to save the file if there is an error parsing it. The problem is that the parser is using a Stream Reader and if an error occurs it just saves the empty file and not the file contents.
Dim file As HttpPostedFile = context.Request.Files(0)
If Not IsNothing(file) AndAlso file.ContentLength > 0 AndAlso Path.GetExtension(file.FileName) = ".txt" Then
Dim id As Integer = (Int32.Parse(context.Request("id")))
Try
ParseFile(file, id)
context.Response.Write("success")
Catch ex As Exception
Dim filename As String = file.FileName
Dim uploadPath = context.Server.MapPath("~/Errors/MyStudentDataFiles/")
file.SaveAs(uploadPath + id.ToString() + filename)
End Try
Else
context.Response.Write("error")
End If
My ParseFile method is something like this
Protected Sub ParseFile(ByVal studentLoanfile As HttpPostedFile, ByVal id As Integer)
Using r As New StreamReader(studentLoanfile.InputStream)
line = GetLine(r)
End Using
End Sub
Is there a way to Clone the file before it gets passed into the parseFile sub or a way to read the file without loosing the contents? Thanks in advance
For anyone who runs into this problem in the future, I ended up reading the file to the end and saving it into a variable. Then converted it back into a memory stream to use for the parser. If an error occurs, I just create a new file with the string. This is the code I used.
Dim id As Integer = (Int32.Parse(context.Request("id")))
'Read full file for error logging
Dim content As String = [String].Empty
Using sr = New StreamReader(uploadedFile.InputStream)
content = sr.ReadToEnd()
End Using
'Convert it back into a stream
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(content)
Dim stream As New MemoryStream(byteArray)
Try
ParseFile(stream, id, content)
context.Response.Write("success")
Catch ex As Exception
Dim filename As String = uploadedFile.FileName
Dim uploadPath = context.Server.MapPath("~/Errors/MyStudentDataFiles/")
'Save full file on error
Using sw As StreamWriter = File.CreateText(uploadPath + id.ToString() + filename)
sw.WriteLine(content)
End Using
context.Response.Write("error")
Throw ex
End Try
Else
context.Response.Write("error")
End If