Question

Using the following program I’m trying to insert all the filenames listed in a folder on ftp server into a SQL table.

While Writing to table I’m getting an error

c# cannot access a disposed object. object name
‘system.net.sockets.networkstream’

reader.ReadToEnd() Writing the whole stream where I want one by one filename.

namespace Examples.System.Net
{
    public class WebRequestGetExample
    {
        public static void Main()
        {

            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://myftpaddress.com/0708/");
            request.Method = WebRequestMethods.Ftp.ListDirectory;


            request.Credentials = new NetworkCredential("vish10", "MyPasswd");

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();

            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            Console.WriteLine(reader.ReadToEnd());

            SqlConnection sqlConnection1 = new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=DMSTG;Data Source=.");
            SqlCommand cmd = new SqlCommand();

            cmd.CommandText = @"Insert into FTPfileList0708Folder
                                           values('" + reader.ReadToEnd().ToString() + "')";
            cmd.Connection = sqlConnection1;

            sqlConnection1.Open();

            cmd.ExecuteNonQuery();
            sqlConnection1.Close();

            Console.WriteLine("Directory List Complete, status {0}", response.StatusDescription);

            reader.Close();
            response.Close();
        }
    }
}

Answer 1

You’ve already read the complete response here:

FtpWebResponse response = (FtpWebResponse)request.GetResponse();

Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
Console.WriteLine(reader.ReadToEnd());

Once you’ve read it, you can’t read it again.

Just change to

string text = reader.ReadToEnd();

… and then add appropriate using statements to handle resources properly:

string text;
using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
{
    using (Stream responseStream = response.GetResponseStream())
    {
        // No need to dispose of the StreamReader as we're already
        // disposing of the stream. It wouldn't do any harm though.
        // Is the text definitely encoded in UTF-8 though?
        text = new StreamReader(responseStream).ReadToEnd();
    }
}

You should have similar using statements for all of your SQL-related resources.
That solves the immediate problem – but it’s not clear what that has to do with the specific business of reading filenames. That will depend on what format the filenames are in within the text. From what I remember, FTP is actually very poorly specified when it comes to this sort of thing.

I would recommend two significant changes:

• Split your code up into logical methods:
  • Handling the FTP request itself
  • Parsing the data into a suitable format
  • Inserting the data into the database
• Try to find a higher-level FTP library which will know how to do the parsing for you