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A1880

Intermediate

  • "A1880" is male
  • "A1880" started this thread

Posts: 500

Date of registration: Jan 1st 2009

Location: Hanover, Germany

Occupation: Software Engineer

Hobbies: Hilbert Curves

  • Send private message

1

Sunday, September 6th 2009, 4:06pm

error writing text to VBFileHandler file

Hi,
I found a problem writing to a file:

Jabaco Source

 
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Public Sub Command1_Click()
   Dim fileName As String = System.getenv("tmp") & "\myFile.txt" 
   Dim f As VBFileHandler = Open(fileName, Output, Write, Shared)
   Dim i As Integer 
   Dim cnt As Integer = 0
   Dim res As Boolean 
   
   For i = 1 To 100
      res = f.writeString(cnt & ": neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, " & _
                          "consectetur, adipisci velit, sed quia non numquam eius")
      cnt = cnt + 1
      
      If Not res Then
         Debug.Print "premature exit at line " & cnt
      End If
   Next i
   
   f.close 
   
   Debug.Print cnt & "Lines written to " & fileName
   
End Sub


The file ends up with just one line of text.
Only the last line is written properly.
The first 99 lines are ignored/skipped.
The writeString always returned a true status.

The source code in the Jabaco framework:

Jabaco Source

 
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Public Function writeString(s As String) As Boolean     
    If myOutput = Nothing Then Exit Function    
    If myMode <> Append Then myOutput.getChannel.truncate 0    
    myOutput.write s    
    writeString = True 
End Function


My impression is that "truncate 0" discards all but the last line of text.

The workaround for the time being is something like this:

Source code

 
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Private myWriter As java#io#PrintWriter

myWriter = New java#io#PrintWriter(New java#io#BufferedWriter(New java#io#FileWriter(f)))

myWriter.println cnt & ": neque porro quisquam est, ..."

myWriter.close


Anny comments?

Greetings!

A1880

A1880

Intermediate

  • "A1880" is male
  • "A1880" started this thread

Posts: 500

Date of registration: Jan 1st 2009

Location: Hanover, Germany

Occupation: Software Engineer

Hobbies: Hilbert Curves

  • Send private message

2

Tuesday, February 2nd 2010, 11:39am

I guess the implementation of "FileSystem" in the Jabaco framework is not complete yet.

As a workaround, you can use Java mechanisms directly.

Sample:

Jabaco Source

 
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Option Explicit

Public Sub Command1_Click()
   Dim lnr As LineNumberReader 
   Dim s As String
   
   On Error Goto ErrHandler

   lnr = openReader("w:\some not existing path\foo.xyz")
   
   s = lnr.readLine()
   
   MsgBox s
   
   Exit Sub
   
ErrHandler:
   MsgBox "click handler failed"
End Sub



Public Function openReader(fileName As String) As java#io#LineNumberReader 
   Dim f As LineNumberReader = Null

   On Error Goto ErrHandler
   
  	f = New LineNumberReader(New java#io#InputStreamReader( _
            New java#io#FileInputStream(fileName), _
            java#nio#charset#Charset.forName("ISO8859-1") ))

   Exit Function
   
ErrHandler:
   MsgBox "Could not open file '" & fileName & "'" _
     & vbCrLf & "(" & Err.getMessage() & "'"
End Function


Volunteers for testing, fixing and improving the open source Jabaco framework are welcome!

Greetings

A1880

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