Client Server Architecture 1

Question

I have the following code for a server:

public class TCPListener
    {
        public static void Main()
        {
            try
            {
                JSONMobile json_mobile = new JSONMobile();

                IPAddress ip_address = IPAddress.Parse("127.0.0.1");
                int port_number = 5000;

                TcpListener server = new TcpListener(ip_address, port_number);
                server.Start();

                Byte[] bytes = new Byte[2048];
                String received_data = null;
                JObject obj = new JObject();

                while (true)
                {
                    TcpClient client = server.AcceptTcpClient();
                    received_data = null;

                    NetworkStream stream = client.GetStream();
                    int i;

                    while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
                    {
                        received_data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
                        obj = json_mobile.DeserializeToObject<JObject>(received_data);

                        string transaction_status = obj["Transaction_Status"].ToString();
                        string transaction_id = obj["Transaction_ID"].ToString();
                        string processed_date = obj["Processed_Date"].ToString();
                        string customer_username = obj["Customer_Username"].ToString();

                        byte[] msg = System.Text.Encoding.ASCII.GetBytes("The message was received!");
                        stream.Write(msg, 0, msg.Length);
                    }
                    client.Close();
                }
            }
            catch (SocketException)
            {
                //Catch socket exception
            }
        }

I have the following code for the client:

public bool sendTCPMessage(string ip_address, string port, string transaction_id, string customer_username, DateTime date)
        {
            bool success = false;

            try
            {
                int converted_port = Convert.ToInt32(port);
                string converted_date = date.ToString("dd/MM/yyyy HH:mm:ss", CultureInfo.InvariantCulture);
                //int received_bytes_count = 0;
                //string received_data = "";

                JObject obj = new JObject();
                obj["Transaction_Status"] = "Paid";
                obj["Transaction_ID"] = transaction_id;
                obj["Processed_Date"] = converted_date;
                obj["Customer_Username"] = customer_username;

                JSONMobile json_mobile = new JSONMobile();
                string json = json_mobile.SerializeToString(obj);

                //Send the JSON Object
                TcpClient client = new TcpClient(ip_address, converted_port);
                Byte[] sent_message = System.Text.Encoding.ASCII.GetBytes(json);
                NetworkStream stream = client.GetStream();
                stream.Write(sent_message, 0, sent_message.Length);

                //Receive the response
                /*Byte[] received_message = new Byte[2048];
                received_bytes_count = stream.Read(received_message, 0, received_message.Length);

                received_data = System.Text.Encoding.Default.GetString(received_message);*/

                //Close the connection
                stream.Close();
                client.Close();

                success = true;
            }
            catch (Exception)
            {
                success = false;
            }
            return success;
        }

Now, I have opened port 5000 in Windows Firewall. However, if I try to telnet 127.0.0.1 5000 (the server), all I get is a bad request message. Obviously, if I place a breakpoint in the server and run the client, the breakpoint never enters. What is the problem? What am I doing wrong?

possible duplicate of [Problem reading from a TCPClient](http://stackoverflow.com/questions/6178883/problem-reading-from-a-tcpclient) — jgauffin, Jul 03 '13 at 21:50
I have edited your title. Please see, "[Should questions include “tags” in their titles?](http://meta.stackexchange.com/questions/19190/)", where the consensus is "no, they should not". — John Saunders, Jul 03 '13 at 23:04
BTW, never ignore exceptions. The exception could be telling you exactly what's wrong, and you'll never know it. — John Saunders, Jul 03 '13 at 23:05

score 1 · Accepted Answer · answered Jul 03 '13 at 21:41

1

I created a new solution around your server class and ran it (removing references to JSONMobile). Then using standard telnet I was able to get responses from the server.

So I would say that it is environmental. Since you have already opened a port some things that you could try are;

disable firewall (but given you are using localhost the firewall should not really cause problems)
check that you do not have another application already listening on that port
try another port

answered Jul 03 '13 at 21:41

Chris Opthoog

36
3

Thanks for the response :) As a matter of fact, I copied the code to a console application and it works. When I put it in a web application, the code does not work for some reason or another. The telnet client connects however I don't receive a response. – Matthew Jul 04 '13 at 08:51

Client Server Architecture 1

1 Answers1