Asynchronous Socket Utility Classes – Part II

This is part two of William's series on using Asynchronous Socket Utility Classes in C#. In this article, William will describe the code for the server side. Once you have read the two parts you should have no troubles with these classes.

Author Info:

By: William Kennedy

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March 31, 2003

TABLE OF CONTENTS:

//********************************************
/// <summary> Called when a message is extracted from the socket </summary>
/// <param name="pSocket"> The SocketClient object the message came from </param>
/// <param name="iNumberOfBytes"> The number of bytes in the RawBuffer inside the SocketClient </param>
static public void MessageHandlerServer(CSocketClient pSocket, Int32 iNumberOfBytes)
{
try
{
    // Find a complete message
    String strMessage = System.Text.ASCIIEncoding.ASCII.GetString(pSocket.GetRawBuffer, 0, iNumberOfBytes);
    Console.WriteLine(strMessage);
    // Send the following HTTP command back
    String strServerResponse = "HTTP/1.1 200 OK\n" +
      "Date: Tue, 18 Feb 2003 18:47:39 GMT\n" +
      "Server: Apache/1.3.27 (Unix) (Red-Hat/Linux) mod_perl/1.24_01 PHP/4.2.2 FrontPage/5.0.2 mod_ssl/2.8.12 OpenSSL/0.9.6b\n" +
      "Last-Modified: Sat, 25 Jan 2003 21:45:30 GMT\n" +
      "ETag: \"2201ab-11cd-3e33057a\"\n" +
      "Accept-Ranges: bytes\n" +
      "Content-Length: 53\n" +
      "Keep-Alive: timeout=15, max=100\n" +
      "Connection: Keep-Alive\n" +
      "Content-Type: text/html\n\n" +
      "<html> <body> <h1> Hello World! </h1> </body> </html>\n";
    pSocket.Send(strServerResponse);
}
catch (Exception pException)
{
    Console.WriteLine(pException.Message);
}
}

Add the AcceptHandler next. This is allow us to be notified when a connection is established to our server.

//********************************************
/// <summary> Called when a socket connection is accepted </summary>
/// <param name="pSocket"> The SocketClient object the message came from </param>
static public void AcceptHandler(CSocketClient pSocket)
{
Console.WriteLine("Accept Handler");
Console.WriteLine("IpAddress: " + pSocket.GetIpAddress);
}

The TestServer method will be used to start the server. We will listen for connections on port 9000 using the network card configured under our machine name.

//*********************************************
/// <summary> Function to test the CSocketServer class </summary>
static void TestServer()
{
try
{
    // Instantiate a CSocketServer object
    CSocketServer pSocketServer = new CSocketServer();
    // Start listening for connections
    pSocketServer.Start(System.Environment.MachineName, 9000, 1024, 10240, null,
      new CSocketServer.MESSAGE_HANDLER(MessageHandlerServer),
      new CSocketServer.ACCEPT_HANDLER(AcceptHandler),
      new CSocketServer.CLOSE_HANDLER(CloseHandler),
      new CSocketServer.ERROR_HANDLER(ErrorHandler));
    Console.WriteLine("Waiting for a client connection on Machine: {0} Port: {1}", System.Environment.MachineName, 9000);
    // Stay here until you are ready to shutdown the server
    Console.ReadLine();
    pSocketServer.Dispose();
}
catch (Exception pException)
{
    Console.WriteLine(pException.Message);
}
}

In the Main method, comment out the call to TestClient and add the call to TestServer. Now we are ready to start our server and test it.

//**********************************************
/// <summary> Function to test the CSocketClient class </summary>
static void Main(string[] args)
{
// Test the CSocketClient class
// TestClient();

// Test the CSocketClient class
TestServer();
}

Start the server and launch your browser. Our server is listening for connections on our local machine on port 9000. You need the machine name or ipaddress of our local machine. In the address bar type the following: http://machinename:9000 . This will have the browser connect to our server on port 9000 and our server will send the browser back the HTML statement that will display Hello World on the browser.