Connect to Universal Messaging using JMS

HelloUMJNDI.java

import java.util.Hashtable;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.Topic;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class HelloUMJNDI {

	public static void main(String[] args) throws NamingException, JMSException {
		Hashtable<String, String> env = new Hashtable<>();
		env.put(Context.INITIAL_CONTEXT_FACTORY, 
		    "com.pcbsys.nirvana.nSpace.NirvanaContextFactory");
		env.put(Context.PROVIDER_URL, "nsp://local-dev:9000");

		Context ctx = new InitialContext(env);
		ConnectionFactory connFactory = (ConnectionFactory) ctx.lookup("local_um");
		Connection conn = connFactory.createConnection();
		
		Topic topic = (Topic) ctx.lookup("externalClientTopic");
		
		Session session = conn.createSession(false, Session.CLIENT_ACKNOWLEDGE);
		MessageProducer producer = session.createProducer(topic);

		Message message = session.createTextMessage("Hello World !");
		producer.send(message);
		
		conn.close();
		ctx.close();
	}

}

@mmacphail, i am getting an error [Root exception is com.pcbsys.nirvana.client.nSessionNotConnectedException: The session is not currently connected to the server. Unable to perform the request:Session has been closed via another thread].

Both threads use the same session, but it seems one thread closed the session. You want to open the session in each independent thread, or do not close the session at all in the threads and close it when the app finishes.