PROGRAM 2


// Chat.idl
 
module Chat
{
    interface ChatClientServices
    {
        void printMessage (in string message);
    };
 
    interface ChatServerServices
    {
        boolean register (in string clientName, in ChatClientServices clientServices);
        boolean chatPublic (in string sender, in string message);
        boolean chatPrivate (in string sender, in string receiver, in string message);
        boolean unregister (in string clientName);
    };
};

// ChatClient.java
 
import Chat.*;
import org.omg.CosNaming.*;
import org.omg.CORBA.*;
import java.io.*;
 
public class ChatClient
{
    public static void main (String args [])
    {
        try
        {
            // Create and initialize the ORB
            ORB orb = ORB.init (args, null);
 
            // Get the root naming context
            org.omg.CORBA.Object objRef = orb.resolve_initial_references ("NameService");
            NamingContext ncRef = NamingContextHelper.narrow (objRef);
 
            // Resolve the Object Reference in Naming
            NameComponent nc = new NameComponent ("Chat", "");
            NameComponent path [] = {nc};
            ChatServerServices chatServerServices = ChatServerServicesHelper.narrow (ncRef.resolve (path));
 
            ChatClientServicesImplementation chatClientServices = new ChatClientServicesImplementation ();
            orb.connect (chatClientServices);
 
            // Enter client's name
            InputStreamReader inputReader = new InputStreamReader (System.in);
            BufferedReader bufferedReader = new BufferedReader (inputReader);
            System.out.print ("Enter name: ");
            String name = bufferedReader.readLine ();
 
            // Register client
            while (! chatServerServices.register (name, chatClientServices))
            {
                System.out.print ("This name is already taken.  Enter another name: ");
                name = bufferedReader.readLine ();
            }
 
            // Enter private or public chat
            System.out.print ("Enter a specific name for a private chat or 'public' for a public chat: ");
            String type = bufferedReader.readLine ();
            String name2 = type;
 
            // Get message and chat
            while (true)
            {
                // Get msg from client
                String msg = bufferedReader.readLine ();
                msg = name + "> " + msg;
 
                // Unregister client if msg = "exit"
                if (msg.compareTo (name + "> " + "exit") == 0)
                {
                    break;
                }
 
                // Private and public chat
                if (type.compareTo ("public") == 0)
                {
                    if (! chatServerServices.chatPublic (name, msg))
                    {
                        System.out.println (name + "> No one is on-line");
                    }
                }
                else
                {
                    if (! chatServerServices.chatPrivate (name, name2, msg))
                    {
                        System.out.println (name + "> " + name2 + " is not on-line");
                    }
                }
            }
            chatServerServices.unregister (name);
        }
        catch (Exception e)
        {
            System.out.println ("Error: " + e) ;
            e.printStackTrace (System.out);
        }
    }
}
 
// ChatClientServicesImplementation.java
 
class ChatClientServicesImplementation extends _ChatClientServicesImplBase
{
    // Constructor
    public ChatClientServicesImplementation ()
    {
    }
 
    // Print message
    public void printMessage (String msg)
    {
        System.out.println (msg);
    }
}

// ChatServer.java
 
import Chat.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import java.util.*;
 
public class ChatServer
{
    public static void main (String args [])
    {
        try
        {
            // Create and initialize the ORB
            ORB orb = ORB.init (args, null);
 
            // Create servant and register it with the ORB
            ChatServerServicesImplementation chatServerServices = new ChatServerServicesImplementation ();
            orb.connect (chatServerServices);
 
            // Get the root naming context
            org.omg.CORBA.Object objRef = orb.resolve_initial_references ("NameService");
            NamingContext ncRef = NamingContextHelper.narrow (objRef);
 
            // Bind the Object Reference in Naming
            NameComponent nc = new NameComponent ("Chat", "");
            NameComponent path [] = {nc};
            ncRef.rebind (path, chatServerServices);
 
            // Wait for invocations from clients
            java.lang.Object sync = new java.lang.Object ();
            synchronized (sync)
            {
                sync.wait ();
            }
        }
        catch (Exception e)
        {
            System.err.println ("Error: " + e);
            e.printStackTrace (System.out);
        }
    }
}
 
// ChatServerServicesImplementation.java
 
class ChatServerServicesImplementation extends _ChatServerServicesImplBase
{
    private Hashtable clientServicesList;
 
    // Constructor
    public ChatServerServicesImplementation ()
    {
        clientServicesList = new Hashtable ();
    }
 
    // Register clients
    public boolean register (String clientName, ChatClientServices clientServices)
    {
        if (! clientServicesList.containsKey (clientName))
        {
            clientServicesList.put (clientName, clientServices);
            return true;
        }
        else
        {
            return false;
        }
    }
 
    // Public chat
    public boolean chatPublic (String sender, String msg)
    {
        Enumeration e = clientServicesList.elements ();
        if (clientServicesList.size () == 1 && clientServicesList.containsKey (sender))
        {
            return false;
        }
        else
        {
            while (e.hasMoreElements ())
            {
                ChatClientServices client = (ChatClientServices) e.nextElement ();
                client.printMessage (msg);
            }
        }
        return true;
    }
 
    // Private chat
    public boolean chatPrivate (String sender, String receiver, String msg)
    {
        ChatClientServices client2 = (ChatClientServices) clientServicesList.get (receiver);
        if (client2 != null)
        {
            client2.printMessage (msg);
        }
        else
        {
            return false;
        }
        ChatClientServices client1 = (ChatClientServices) clientServicesList.get (sender);
        if (client1 != null)
        {
            client1.printMessage (msg);
        }
        return true;
    }
 
    // Unregister clients
    public boolean unregister (String clientName)
    {
         if (clientServicesList.containsKey (clientName))
         {
             clientServicesList.remove (clientName);
             return true;
         }
         else
         {
             return false;
         }
    }
}

// Chat.out

// Client 1

Enter name: Anthony 
Enter a specific name for a private chat or 'public' for a public chat: public
Hello, Stacey!
Anthony> Hello Stacey!
Stacey> Hello Anthony!
exit

// Client 2

Enter name: Stacey
Enter a specific name for a private chat or 'public' for a public chat: public
Anthony>Hello, Stacey!
Hello, Anthony!
Stacey> Hello, Anthony!
exit               




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