Android Question FTP server issue

Private Sub NormalizePath(p As String) As String
    If p.StartsWith("/") Or p.StartsWith("\") Then p = p.SubString(1)
    
    #if B4A Or B4J
    Dim jo As JavaObject
    jo.InitializeNewInstance("java.io.File", Array(File.Combine(mServer.BaseDir, p)))
    Dim CanonicalPath As String = jo.RunMethod("getCanonicalPath", Null) 
    Log("CanonicalPath:" & CanonicalPath.ToLowerCase)
    Log("BaseDir:" & mServer.BaseDir.ToLowerCase)
    Log(CanonicalPath.ToLowerCase.StartsWith(mServer.BaseDir.ToLowerCase))
    If CanonicalPath.ToLowerCase.StartsWith(mServer.BaseDir.ToLowerCase) Then
        Dim r As String = CanonicalPath.SubString(mServer.BaseDir.Length).Replace("\", "/")
        If r.Length = 0 Then Return "/" Else Return r
    Else
        SendResponse(450, "Invalid path: " & p)
        Return ""
    End If