package server;

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Title:        HelloServer class
 * Description:  Server that says "Hello Walrus" to a client and then terminates
 *
 * Copyright:   (c) 2004, 2005
 * Company:     The Open University
 * @author M257 Course Team
 * @version      1.0
 */
public class HelloServer
{
    private ServerSocket serverSocket;
    private Socket socket;
    // streams for communication to client
    private OutputStream os;
    private PrintWriter toClient;
    // use a high numbered non-dedicated port
    private static final int PORT_NUMBER = 3000;
    private static final String MESSAGE_TO_CLIENT = "Hello Walrus";

    // constructor
    public HelloServer()
    {
        System.out.println("...Server starting up");

        try
        {
            // create a ServerSocket object to listen on the port
            serverSocket = new ServerSocket(PORT_NUMBER);
        }
        catch (IOException e)
        {
            System.out.println("Trouble with ServerSocket on port " + PORT_NUMBER
                    + ": " + e);
        }
    } // end constructor

    public void run()
    {
        try
        {
            // wait for a connection request
            socket = serverSocket.accept();
            System.out.println("...Connection established");

            openStreams();

            toClient.println(MESSAGE_TO_CLIENT);

            closeStreams();
            socket.close();
        }
        catch (IOException e)
        {
            System.out.println("Trouble with a connection " + e);
        }
    }

    // set up streams for communicating with the client
    private void openStreams() throws IOException
    {
        final boolean AUTO_FLUSH = true;
        os = socket.getOutputStream();
        toClient = new PrintWriter(os, AUTO_FLUSH);
        System.out.println("...Streams set up");
    }

    // close output streams to client
    private void closeStreams() throws IOException
    {
        toClient.close();
        os.close();
        System.out.println("...Streams closed down");
    }
} // end class