Musings…

I was reading this article from IBM about how to communicate with Geronimo’s JMS server(ActiveMQ). The sample for the non-J2EE client does not work!

What I did is to take the code from the article and edit the typo and voila! I got some prototype code! I am using IBM Websphere Community Edition(IBM WAS CE), which is synonymous to Geronimo(at least for the first version). By the way, I added the sender code.

Here are the simple steps:

1. Run Geronimo or IBM WAS CE
2. Compile these two classes. Take note that you need the ff. jar files to compile and run these successfully. Here’s the list:

- geronimo-j2ee_1.4_spec.jar
- commons-logging-1.0.4.jar
- concurrent-1.3.4.jar
3. Run the clients.
You’ll find it somewhere under the Geronimo or WAS CE installation directory.

The receiver class

——start————

import java.util.logging.Logger;

import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.activemq.ActiveMQConnectionFactory;

public class JMSReceiver {
protected Queue queue;

protected String queueName = “SendReceiveQueue”;
protected String url = “tcp://localhost:61616″;

Logger logger = Logger.getAnonymousLogger();

protected int ackMode = Session.AUTO_ACKNOWLEDGE;

public static void main(String[] args) {
JMSReceiver msgReceiver = new JMSReceiver();
msgReceiver.run();
}

public void run() {
try {
ActiveMQConnectionFactory connectionFactory =
new ActiveMQConnectionFactory(url);
QueueConnection connection =
(QueueConnection)
connectionFactory.createConnection();
connection.start();

MessageConsumer consumer = null;

QueueSession session = connection.createQueueSession(
false,
Session.AUTO_ACKNOWLEDGE);

queue = session.createQueue(queueName);
consumer = session.createReceiver(queue);
logger.info(”Waiting for message (max 5)”);
for (int i = 0; i < 5; i++) {
Message message = consumer.receive();
processMessage(message);
}
logger.info(”Closing connection”);
consumer.close();
session.close();
connection.close();

} catch (Exception e) {
logger.info(”Caught: ” + e);
e.printStackTrace();
}
}

public void processMessage(Message message) {
try {
TextMessage txtMsg = (TextMessage) message;
logger.info(”Received a message: ” + txtMsg.getText());
} catch (Exception e) {
logger.info(”Caught: ” + e);
e.printStackTrace();
}
}

}——–end———

The sender class

——————-
import java.util.logging.Logger;

import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.activemq.ActiveMQConnectionFactory;

public class JMSSender {

private Queue receiveQueue = null;
protected String queueName = “SendReceiveQueue”;
protected String url = “tcp://localhost:61616″;
Logger logger = Logger.getAnonymousLogger();

public static void main(String[] args) {
JMSSender msgSender = new JMSSender();
msgSender.run();
}

public void run() {
QueueConnection queueConn = null;
QueueSession queueSess = null;
TextMessage myMessage = null;
QueueSender queueSender = null;

try {

ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(
url);

queueConn = factory.createQueueConnection();
queueSess = queueConn.createQueueSession(false,
Session.AUTO_ACKNOWLEDGE);

receiveQueue = queueSess.createQueue(queueName);
queueSender = queueSess.createSender(receiveQueue);

myMessage = queueSess.createTextMessage();

myMessage.setText(”test from JMS client 2″);
queueSender.send(myMessage);

queueSender.close();
queueSess.close();
queueConn.close();

} catch (Exception e) {
logger.info(”Caught: ” + e);
e.printStackTrace();
}
}
}
—————–

Anyway, I hope this code might be useful for those interested in JMS. Enjoy and happy coding! If you have queries or if anything is not working, just drop me a note.

I was curious on how fast is it to do a web application with Ruby on Rails. They say it is really fast compared to creating a Java web application.

After some searching over the net, I found Locomotive. Locomotive is a pre-packaged application which bundles all the requirements of a Rails web application. It aims to get you started with Ruby on Rails minus the headache. It is self-contained. It can even run with the other ruby installations. Too bad it only runs on a Mac. I didn’t wait any longer and installed it in my machine. Installation is a breeze. Just click and drag it to the applications directory. The interface to control running instances of rails apps is straightforward.

After that I looked for some tutorials, I found this article the easiest to understand.

http://alliance.seas.upenn.edu/~matuszek/wiki700/index.php?n=Main.Locomotive

It took me maybe less than an hour to create my first Rails application. Hmmm…I don’t even have background with Rails! I was amazed how fast it can be done. Actually, I was stuck because my crappy text editor couldn’t save the proper filename. Dang! It could just have been a few minutes. Haha! The sample is not just the simple Hello World thingy but it has some database stuff wherein the users are able to do the usual CRUD routine from the web browser.

Rails is very interesting. I think I’ll use this thing for my pet projects. hehehe