Java - GTalk Client using SMACK XMPP API

	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.util.Collection;
	import java.util.Iterator;
	import org.jivesoftware.smack.Chat;
	import org.jivesoftware.smack.ConnectionConfiguration;
	import org.jivesoftware.smack.MessageListener;
	import org.jivesoftware.smack.Roster;
	import org.jivesoftware.smack.RosterEntry;
	import org.jivesoftware.smack.XMPPConnection;
	import org.jivesoftware.smack.XMPPException;
	import org.jivesoftware.smack.packet.Message;


	/**
	 *
	 * @author dhanoopbhaskar
	 */
	public class GtalkClient implements Runnable, MessageListener {
	   
	    ConnectionConfiguration connConfig = null;
	    XMPPConnection xMPPConnection = null;
	    BufferedReader readFromKeyboard = null;
	    String toAddresss = null;
	    String[] buddies = null;
	    int buddySize = 0;


	    public GtalkClient() {
	        /**
	         * Set the 'ConnectionConfiguration' with
	         * -host name
	         * -port number
	         * -service name
	         */
	        connConfig = new ConnectionConfiguration("talk.google.com", 5222, "gmail.com");
	        /**
	         * Create an instance of 'XMPPConnection' with the already created
	         * instance of 'ConnectionConfiguration'
	         */
	        xMPPConnection = new XMPPConnection(connConfig);      
	        try {
	            /**
	             * Connecting to the service
	             */
	            xMPPConnection.connect();
	            /**
	             * Login to the GMail account from which you want to chat
	             * Provide
	             * -email id
	             * -password
	             */
	            xMPPConnection.login("user-name@gmail.com", "password");
	        } catch (XMPPException ex) {
	            System.out.println("Error: " + ex.getMessage());
	        }
	        /**
	         * BufferedReader to read from the keyboard
	         */
	        readFromKeyboard = new BufferedReader(new InputStreamReader(System.in));
	       
	        displayBuddyList();
	       
	        System.out.println("\n\nEnter the recipient's Email Id! or "
	                + "buddy id in the list");
	        try {
	            String temp = readFromKeyboard.readLine();
	            try {
	                int j = Integer.parseInt(temp);
	                toAddresss = getBuddy(j);
	                System.out.println("Buddy <" + toAddresss + "> selected!");
	            } catch(NumberFormatException exp) {
	                toAddresss = temp;
	            }
	        } catch (IOException ex) {
	            System.out.println("Error: " + ex.getMessage());
	        }
	       
	       
	        System.out.println("Enter your chat messages one by one!");
	        System.out.println("[Enter \"quit\" to end the chat!]");
	       
	        String msg = "";
	        while(true) {
	            try {
	                msg = readFromKeyboard.readLine();
	            } catch (IOException ex) {
	                System.out.println("Error: " + ex.getMessage());
	            }
	           
	            if(msg.equalsIgnoreCase("quit")) {
	                System.out.println("--Chat Ended--");
	                break;
	            } else {
	                sendMessage(toAddresss, msg);
	            }
	        }
	    }


	    /**
	     *
	     * @param recipient
	     * @param message
	     */
	    private void sendMessage(String recipient, String message) {
	        /**
	         * Create an instance of 'Chat' providing the recipient's email-id
	         * and an instance of MessageListener interface(The predefined
	         * reference 'this' will do, since the class
	         * implements the MessageListener interface.        
	         */
	        Chat chat = xMPPConnection.getChatManager().createChat(recipient, this);
	        try {
	            /**
	             * Sending the chat message
	             */
	            chat.sendMessage(message);
	        } catch (XMPPException ex) {
	            System.out.println("Error: " + ex.getMessage());
	        }
	    }
	    

	      /**
	       * This method belongs to MessageListener interface.
	       * It listens for the incoming chat messages.
	       */
	    @Override

	    public void processMessage(Chat chat, Message msg) {       
	        String msgStr = msg.getBody();
	        System.out.println("<" + chat.getParticipant() + ">  says " + msgStr);
	    }
	   
	    public static void main(String[] args) {
	        GtalkClient gtalkClient = new GtalkClient();      
	    }


	    @Override
	    public void run() {      
	    }
	   
	    private void displayBuddyList() {
	        Roster roster = xMPPConnection.getRoster();
	        Collection entries = roster.getEntries();


	        System.out.println("\n\n------------Your Buddies!!------------");
	        System.out.println(entries.size() + " buddy(ies):\n");
	        Iterator iter = entries.iterator();
	        buddySize = entries.size();  
	        buddies = new String[buddySize];
	        int i = 0;
	        while (iter.hasNext()) {
	            RosterEntry rosterEntry = (RosterEntry) iter.next();
	            buddies[i] = rosterEntry.getUser();
	            i++;
	            System.out.println(i + ". " + rosterEntry.getUser());          
	        }
	        System.out.println("--------------------------------------");
	    }
	   
	    private String getBuddy(int i) {
	        String buddy = "";
	        if(i > 0 && i <= buddySize) {
	            buddy = buddies[i-1];
	        } else {
	            System.out.println("Invalid Buddy Id!! Selected default one!!");
	            buddy = buddies[0];
	        }
	        return buddy;
	    }
	}