The example I gave really does work, I promise. The null was simply because the XMPPConnection does something I don''t think it should, it only stores the username for successful logins. I think it''s a bug in Smack but it''s one of those kind of things that the Smack developers might call a feature.

After using Smack for a little while I''ve found the Chat class to be kind of worthless so I''ve modified the example to avoid using it. I''ve also created a junk gtalk account so I could leave the username and password values in the example. If you had a problem with the last example it''s probably because you were using username@gmail.com instead of just username. Run this example with

java SendTest

to just wait for messages and auto-reply to them. Run with

java SendTest another.user@gmail.com

to do the same but also send a single message to start the conversation.

This example runs with zero modifications but remember if you don''t change the username and password values then everyone running the example is going to be logged in at the same time and I think only one of you is going to get the messages.

import java.io.IOException;
import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.PacketListener;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.MessageTypeFilter;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.Presence;
import org.jivesoftware.smack.util.StringUtils;

public class SendTest {
    
    // Notice the username is NOT smack.test@gmail.com
    private static String username = "smack.test";
    private static String password = "ignite";
    
    public static class MessageParrot implements PacketListener {
        private XMPPConnection xmppConnection;
        
        public MessageParrot(XMPPConnection conn) {
            xmppConnection = conn;
        }
        
        public void processPacket(Packet packet) {
            Message message = (Message)packet;
            if(message.getBody() != null) {
                String fromName = StringUtils.parseBareAddress(message.getFrom());
                System.out.println("Message from " + fromName + "\n" + message.getBody() + "\n");
                Message reply = new Message();
                reply.setTo(fromName);
                reply.setBody("I am a Java bot. You said: " + message.getBody());
                xmppConnection.sendPacket(reply);
            }
        }
    };
    
    
    public static void main( String[] args ) {
        
        System.out.println("Starting IM client");
        
        // gtalk requires this or your messages bounce back as errors
        ConnectionConfiguration connConfig = new ConnectionConfiguration("talk.google.com", 5222, "gmail.com");
        XMPPConnection connection = new XMPPConnection(connConfig);
        
        try {
            connection.connect();
            System.out.println("Connected to " + connection.getHost());
        } catch (XMPPException ex) {
            //ex.printStackTrace();
            System.out.println("Failed to connect to " + connection.getHost());
            System.exit(1);
        }
        try {
            connection.login(username, password);
            System.out.println("Logged in as " + connection.getUser());
            
            Presence presence = new Presence(Presence.Type.available);
            connection.sendPacket(presence);
            
        } catch (XMPPException ex) {
            //ex.printStackTrace();
            // XMPPConnection only remember the username if login is succesful
            // so we can''t use connection.getUser() unless we log in correctly
            System.out.println("Failed to log in as " + username);
            System.exit(1);
        }
        
        PacketFilter filter = new MessageTypeFilter(Message.Type.chat);
        connection.addPacketListener(new MessageParrot(connection), filter);
        
        if(args.length > 0) {
            // google bounces back the default message types, you must use chat
            Message msg = new Message(args[0], Message.Type.chat);
            msg.setBody("Test");
            connection.sendPacket(msg);
        }
        
        System.out.println("Press enter to disconnect\n");
        
        try {
            System.in.read();
        } catch (IOException ex) {
            //ex.printStackTrace();
        }
        
        connection.disconnect();
    }
}

Hey guys,

Thanks for the bug report. I re-opened SMACK-224 and marked it to be fixed for the next release. I''m going to have to figure out some way to make both SSO and Google work, though.

-Matt