QueueSenderExample.java

import java.util.Random;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class QueueSenderExample {

		public static void main(String [] args) {
			String host = "localhost";
			GameObtainer sender = null;
			try {
				sender = new GameObtainer(host);
				sender.sendMessages();
			} catch (NamingException | JMSException e) {
				System.err.println("Program aborted");
			} finally {
				if(sender != null) {
					try {
						sender.close();
					} catch (Exception e) { }
				}
			}
		}
		
		private String host;
		public QueueSenderExample(String host) throws NamingException, JMSException {
			this.host = host;
			
			// Access JNDI
			createJNDIContext();
			
			// Lookup JMS resources
			lookupConnectionFactory();
			lookupQueue();
			
			// Create connection->session->sender
			createConnection();

		}
		
		
		private Context jndiContext;
		private void createJNDIContext() throws NamingException {
			try {
				
				System.setProperty("org.omg.CORBA.ORBInitialHost", host);
				System.setProperty("org.omg.CORBA.ORBInitialPort", "3700");
				
				jndiContext = new InitialContext();
				
			} catch (NamingException e) {
				System.err.println("Could not create JNDI API context: " + e);
				throw e;
			}
		}
		
		private ConnectionFactory connectionFactory;
		private void lookupConnectionFactory() throws NamingException {
			try {
				connectionFactory = (ConnectionFactory)jndiContext.lookup("jms/TestConnectionFactory");
			} catch (NamingException e) {
				System.err.println("JNDI API JMS connection factory lookup failed: " + e);
				throw e;
			}
		}
		
		private Queue queue;
		private void lookupQueue() throws NamingException {

			try {
				queue = (Queue)jndiContext.lookup("jms/TestQueue");
			} catch (NamingException e) {
				System.err.println("JNDI API JMS queue lookup failed: " + e);
				throw e;
			}
		}
		
		private Connection connection;
		private void createConnection() throws JMSException {
			try {
				connection = connectionFactory.createConnection();
				connection.start();
			} catch (JMSException e) {
				System.err.println("Failed to create connection to JMS provider: " + e);
				throw e;
			}
		}
		
		public void sendMessages() throws JMSException {
			createSession();
			createSender();			
			int count = 1 + new Random().nextInt(10);
			TextMessage message = session.createTextMessage(); 
			for(int i=1; i<=count; ++i) {
				message.setText("This is message "+i);
				queueSender.send(message);
				System.out.println("Sending message "+i);
			}
			// send non-text control message to end
			queueSender.send(session.createMessage());
		}
		
		
		private Session session;
		private void createSession() throws JMSException {
			try {
				session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
			} catch (JMSException e) {
				System.err.println("Failed to create session: " + e);
				throw e;
			}
		}
		
		// Was: QueueSender
		private MessageProducer queueSender;
		private void createSender() throws JMSException {
			try {
				queueSender = session.createProducer(queue);
			} catch (JMSException e) {
				System.err.println("Failed to create session: " + e);
				throw e;
			}
		}
		
		public void close() {
			if(connection != null) {
				try {
					connection.close();
				} catch (JMSException e) { }
			}
		}
		
	}