CHAPTER 6 Messaging on JBoss - JMS Configuration and Architecture

A P2P JMS client example

package org.jboss.chap6.ex1;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Queue;

import javax.jms.QueueConnection;

import javax.jms.QueueConnectionFactory;

import javax.jms.QueueReceiver;

import javax.jms.QueueSender;

import javax.jms.QueueSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import EDU.oswego.cs.dl.util.concurrent.CountDown;

/** A complete JMS client example program that sends a

TextMessage to a Queue and asynchronously receives the

message from the same Queue.

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class SendRecvClient

{

static CountDown done = new CountDown(1);

QueueConnection conn;

QueueSession session;

Queue que;

public static class ExListener implements MessageListener

{

public void onMessage(Message msg)

{

done.release();

TextMessage tm = (TextMessage) msg;

try

{

System.out.println("onMessage, recv text="

+ tm.getText());

}

catch(Throwable t)

{

t.printStackTrace();

}

}

}

public void setupPTP()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

QueueConnectionFactory qcf = (QueueConnectionFactory) tmp;

conn = qcf.createQueueConnection();

que = (Queue) iniCtx.lookup("queue/testQueue");

session = conn.createQueueSession(false,

QueueSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void sendRecvAsync(String text)

throws JMSException, NamingException

{

System.out.println("Begin sendRecvAsync");

// Setup the PTP connection, session

setupPTP();

// Set the async listener

QueueReceiver recv = session.createReceiver(que);

recv.setMessageListener(new ExListener());

// Send a text msg

QueueSender send = session.createSender(que);

TextMessage tm = session.createTextMessage(text);

send.send(tm);

System.out.println("sendRecvAsync, sent text="

+ tm.getText());

send.close();

System.out.println("End sendRecvAsync");

}

public void stop() throws JMSException

conn.stop(); {

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

SendRecvClient client = new SendRecvClient();

client.sendRecvAsync("A text msg");

client.done.acquire();

client.stop();

System.exit(0);

}

}

The client may be run using the following command line:

[nr@toki examples]$ ant -Dchap=chap6 -Dex=1p2p run-example

Buildfile: build.xml

...

run-example1p2p:

[java] [INFO,SendRecvClient] Begin SendRecvClient, now=1083649316059

[java] [INFO,SendRecvClient] Begin sendRecvAsync

[java] [INFO,SendRecvClient] onMessage, recv text=A text msg

[java] [INFO,SendRecvClient] sendRecvAsync, sent text=A text msg

[java] [INFO,SendRecvClient] End sendRecvAsync

[java] [INFO,SendRecvClient] End SendRecvClient

 

BUILD SUCCESSFUL

Total time: 9 seconds

A Pub-Sub JMS client example

package org.jboss.chap6.ex1;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Topic;

import javax.jms.TopicConnection;

import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;

import javax.jms.TopicSubscriber;

import javax.jms.TopicSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import EDU.oswego.cs.dl.util.concurrent.CountDown;

/** A complete JMS client example program that sends a

TextMessage to a Topic and asynchronously receives the

message from the same Topic.

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class TopicSendRecvClient

{

static CountDown done = new CountDown(1);

TopicConnection conn = null;

TopicSession session = null;

Topic topic = null;

public static class ExListener implements MessageListener

{

public void onMessage(Message msg)

{

done.release();

TextMessage tm = (TextMessage) msg;

try

{

System.out.println("onMessage, recv text="

+ tm.getText());

}

catch(Throwable t)

{

t.printStackTrace();

}

}

}

public void setupPubSub()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

TopicConnectionFactory tcf = (TopicConnectionFactory) tmp;

conn = tcf.createTopicConnection();

topic = (Topic) iniCtx.lookup("topic/testTopic");

session = conn.createTopicSession(false,

TopicSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void sendRecvAsync(String text)

throws JMSException, NamingException

{

System.out.println("Begin sendRecvAsync");

// Setup the PubSub connection, session

setupPubSub();

// Set the async listener

TopicSubscriber recv = session.createSubscriber(topic);

recv.setMessageListener(new ExListener());

// Send a text msg

TopicPublisher send = session.createPublisher(topic);

TextMessage tm = session.createTextMessage(text);

send.publish(tm);

System.out.println("sendRecvAsync, sent text="

+ tm.getText());

send.close();

System.out.println("End sendRecvAsync");

}

public void stop() throws JMSException

{

conn.stop();

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

System.out.println("Begin TopicSendRecvClient, now="+System.currentTimeMillis());

TopicSendRecvClient client = new TopicSendRecvClient();

client.sendRecvAsync("A text msg, now="+System.currentTimeMillis());

client.done.acquire();

client.stop();

System.out.println("End TopicSendRecvClient");

System.exit(0);

}

}

The client may be run using the following command line:

[nr@toki examples]$ ant -Dchap=chap6 -Dex=1ps run-example

Buildfile: build.xml

...

run-example1ps:

[java] Begin TopicSendRecvClient, now=1083649449640

[java] Begin sendRecvAsync

[java] onMessage, recv text=A text msg, now=1083649449642

[java] sendRecvAsync, sent text=A text msg, now=1083649449642

[java] End sendRecvAsync

[java] End TopicSendRecvClient

 

BUILD SUCCESSFUL

Total time: 3 seconds

Now let's break the publisher and subscribers into separate programs to demonstrate that subscribers only receive messages while they are listening to a topic. See A JMS publisher client. shows a variation of the previous Pub-Sub client that only publishes messages to the "topic/testTopic" topic. The subscriber only client is shown in See A JMS subscriber client..

A JMS publisher client

package org.jboss.chap6.ex1;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Topic;

import javax.jms.TopicConnection;

import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;

import javax.jms.TopicSubscriber;

import javax.jms.TopicSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

/** A JMS client example program that sends a TextMessage to a Topic

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class TopicSendClient

{

TopicConnection conn = null;

TopicSession session = null;

Topic topic = null;

public void setupPubSub()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

TopicConnectionFactory tcf = (TopicConnectionFactory) tmp;

conn = tcf.createTopicConnection();

topic = (Topic) iniCtx.lookup("topic/testTopic");

session = conn.createTopicSession(false,

TopicSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void sendAsync(String text)

throws JMSException, NamingException

{

System.out.println("Begin sendAsync");

// Setup the pub/sub connection, session

setupPubSub();

// Send a text msg

TopicPublisher send = session.createPublisher(topic);

TextMessage tm = session.createTextMessage(text);

send.publish(tm);

System.out.println("sendAsync, sent text="

+ tm.getText());

send.close();

System.out.println("End sendAsync");

}

public void stop() throws JMSException

{

conn.stop();

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

System.out.println("Begin TopicSendClient, now="+System.currentTimeMillis());

TopicSendClient client = new TopicSendClient();

client.sendAsync("A text msg, now="+System.currentTimeMillis());

client.stop();

System.out.println("End TopicSendClient");

System.exit(0);

}

}

A JMS subscriber client

package org.jboss.chap6.ex1;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Topic;

import javax.jms.TopicConnection;

import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;

import javax.jms.TopicSubscriber;

import javax.jms.TopicSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

/** A JMS client example program that synchronously receives a message a Topic

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class TopicRecvClient

{

TopicConnection conn = null;

TopicSession session = null;

Topic topic = null;

public void setupPubSub()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

TopicConnectionFactory tcf = (TopicConnectionFactory) tmp;

conn = tcf.createTopicConnection();

topic = (Topic) iniCtx.lookup("topic/testTopic");

session = conn.createTopicSession(false,

TopicSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void recvSync()

throws JMSException, NamingException

{

System.out.println("Begin recvSync");

// Setup the pub/sub connection, session

setupPubSub();

// Wait upto 5 seconds for the message

TopicSubscriber recv = session.createSubscriber(topic);

Message msg = recv.receive(5000);

if( msg == null )

System.out.println("Timed out waiting for msg");

else

System.out.println("TopicSubscriber.recv, msgt="+msg);

}

public void stop() throws JMSException

{

conn.stop();

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

System.out.println("Begin TopicRecvClient, now="+System.currentTimeMillis());

TopicRecvClient client = new TopicRecvClient();

client.recvSync();

client.stop();

System.out.println("End TopicRecvClient");

System.exit(0);

}

}

Run the TopicSendClient followed by the TopicRecvClient as follows:

[nr@toki examples]$ ant -Dchap=chap6 -Dex=1ps2 run-example

Buildfile: build.xml

...

run-example1ps2:

[java] Begin TopicSendClient, now=1083649621287

[java] Begin sendAsync

[java] sendAsync, sent text=A text msg, now=1083649621289

[java] End sendAsync

[java] End TopicSendClient

[java] Begin TopicRecvClient, now=1083649625592

[java] Begin recvSync

[java] Timed out waiting for msg

[java] End TopicRecvClient

 

BUILD SUCCESSFUL

 

Total time: 10 seconds

The output shows that the topic subscriber client (TopicRecvClient) fails to receive the message sent by the publisher due to a timeout.

A durable topic JMS client example

package org.jboss.chap6.ex1;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Topic;

import javax.jms.TopicConnection;

import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;

import javax.jms.TopicSubscriber;

import javax.jms.TopicSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

/** A JMS client example program that synchronously receives a message a Topic

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class DurableTopicRecvClient

{

TopicConnection conn = null;

TopicSession session = null;

Topic topic = null;

public void setupPubSub()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

TopicConnectionFactory tcf = (TopicConnectionFactory) tmp;

conn = tcf.createTopicConnection("john", "needle");

topic = (Topic) iniCtx.lookup("topic/testTopic");

session = conn.createTopicSession(false,

TopicSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void recvSync()

throws JMSException, NamingException

{

System.out.println("Begin recvSync");

// Setup the pub/sub connection, session

setupPubSub();

// Wait upto 5 seconds for the message

TopicSubscriber recv = session.createDurableSubscriber(topic, "chap6-ex1dtps");

Message msg = recv.receive(5000);

if( msg == null )

System.out.println("Timed out waiting for msg");

else

System.out.println("DurableTopicRecvClient.recv, msgt="+msg);

}

public void stop() throws JMSException

{

conn.stop();

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

System.out.println("Begin DurableTopicRecvClient, now="+System.currentTimeMillis());

DurableTopicRecvClient client = new DurableTopicRecvClient();

client.recvSync();

client.stop();

System.out.println("End DurableTopicRecvClient");

System.exit(0);

}

}

Now run the previous topic publisher with the durable topic subscriber as follows:

[nr@toki examples]$ ant -Dchap=chap6 -Dex=1psdt run-example

Buildfile: build.xml

...

run-example1psdt:

[java] Begin DurableTopicSetup

[java] End DurableTopicSetup

[java] Begin TopicSendClient, now=1083649712652

[java] Begin sendAsync

[java] sendAsync, sent text=A text msg, now=1083649712655

[java] End sendAsync

[java] End TopicSendClient

[java] Begin DurableTopicRecvClient, now=1083649716858

[java] Begin recvSync

[java] DurableTopicRecvClient.recv, msgt=org.jboss.mq.SpyTextMessage {

[java] Header {

[java] jmsDestination : TOPIC.testTopic.DurableSubscriberExample.chap6-ex1dtps

[java] jmsDeliveryMode : 2

[java] jmsExpiration : 0

[java] jmsPriority : 4

[java] jmsMessageID : ID:5-10836497160641

[java] jmsTimeStamp : 1083649716064

[java] jmsCorrelationID: null

[java] jmsReplyTo : null

[java] jmsType : null

[java] jmsRedelivered : false

[java] jmsProperties : {}

[java] jmsPropertiesReadWrite:false

[java] msgReadOnly : true

[java] producerClientId: ID:5

[java] }

[java] Body {

[java] text :A text msg, now=1083649712655

[java] }

[java] }

[java] End DurableTopicRecvClient

 

BUILD SUCCESSFUL

Total time: 6 seconds

Items of note for the durable topic example include:

• The TopicConnectionFactory creation in the durable topic client used a username and password, and the TopicSubscriber creation was done using the createDurableSubscriber(Topic, String) method. This is a requirement of durable topic subscribers. The messaging server needs to know what client is requesting the durable topic and what the name of the durable topic subscription is. We will discuss the details of durable topic setup in the configuration section.
• An org.jboss.chap6.DurableTopicSetup client was run prior to the TopicSendClient . The reason for this is a durable topic subscriber must have registered a subscription at some point in the past in order for the messaging server to save messages. JBoss supports dynamic durable topic subscribers and the DurableTopicSetup client simply creates a durable subscription receiver and then exits. This leaves an active durable topic subscriber on the "topic/testTopic" and the messaging server knows that any messages posted to this topic must be saved for latter delivery.
• The TopicSendClient does not change for the durable topic. The notion of a durable topic is a subscriber only notion.
• The DurableTopicRecvClient sees the message published to the "topic/testTopic" even though it was not listening to the topic at the time the message was published.

A TextMessage processing MDB

package org.jboss.chap6.ex2;

import javax.ejb.MessageDrivenBean;

import javax.ejb.MessageDrivenContext;

import javax.ejb.EJBException;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Queue;

import javax.jms.QueueConnection;

import javax.jms.QueueConnectionFactory;

import javax.jms.QueueSender;

import javax.jms.QueueSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

/** An MDB that transforms the TextMessages it receives and send the transformed

messages to the Queue found in the incoming message JMSReplyTo header.

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class TextMDB implements MessageDrivenBean, MessageListener

{

private MessageDrivenContext ctx = null;

private QueueConnection conn;

private QueueSession session;

public TextMDB()

{

System.out.println("TextMDB.ctor, this="+hashCode());

}

public void setMessageDrivenContext(MessageDrivenContext ctx)

{

this.ctx = ctx;

System.out.println("TextMDB.setMessageDrivenContext, this="+hashCode());

}

public void ejbCreate()

{

System.out.println("TextMDB.ejbCreate, this="+hashCode());

try

{

setupPTP();

}

catch(Exception e)

{

throw new EJBException("Failed to init TextMDB", e);

}

}

public void ejbRemove()

{

System.out.println("TextMDB.ejbRemove, this="+hashCode());

ctx = null;

try

{

if( session != null )

session.close();

if( conn != null )

conn.close();

}

catch(JMSException e)

{

e.printStackTrace();

}

}

public void onMessage(Message msg)

{

System.out.println("TextMDB.onMessage, this="+hashCode());

try

{

TextMessage tm = (TextMessage) msg;

String text = tm.getText() + "processed by: "+hashCode();

Queue dest = (Queue) msg.getJMSReplyTo();

sendReply(text, dest);

}

catch(Throwable t)

{

t.printStackTrace();

}

}

private void setupPTP()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("java:comp/env/jms/QCF");

QueueConnectionFactory qcf = (QueueConnectionFactory) tmp;

conn = qcf.createQueueConnection();

session = conn.createQueueSession(false,

QueueSession.AUTO_ACKNOWLEDGE);

conn.start();

}

private void sendReply(String text, Queue dest)

throws JMSException

{

System.out.println("TextMDB.sendReply, this="+hashCode()

+", dest="+dest);

QueueSender sender = session.createSender(dest);

TextMessage tm = session.createTextMessage(text);

sender.send(tm);

sender.close();

}

}

The MDB ejb-jar.xml and jboss.xml deployment descriptors are shown in See The MDB ejb-jar.xml and jboss.xml descriptors..

The MDB ejb-jar.xml and jboss.xml descriptors

// The ejb-jar.xml descriptor

<?xml version="1.0"?>

<!DOCTYPE ejb-jar

PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN"

"http://java.sun.com/dtd/ejb-jar_2_0.dtd"

>

<ejb-jar>

<enterprise-beans>

<message-driven>

<ejb-name>TextMDB</ejb-name>

<ejb-class>org.jboss.chap6.ex2.TextMDB</ejb-class>

<transaction-type>Container</transaction-type>

<acknowledge-mode>AUTO_ACKNOWLEDGE</acknowledge-mode>

<message-driven-destination>

<destination-type>javax.jms.Queue</destination-type>

</message-driven-destination>

<res-ref-name>jms/QCF</res-ref-name> <resource-ref>

<res-type>javax.jms.QueueConnectionFactory</res-type>

<res-auth>Container</res-auth>

</resource-ref>

</message-driven>

</enterprise-beans>

</ejb-jar>

// The jboss.xml descriptor

<?xml version="1.0"?>

<jboss>

<enterprise-beans>

<message-driven>

<ejb-name>TextMDB</ejb-name>

<destination-jndi-name>queue/B</destination-jndi-name>

<resource-ref>

<res-ref-name>jms/QCF</res-ref-name>

<jndi-name>ConnectionFactory</jndi-name>

</resource-ref>

</message-driven>

</enterprise-beans>

</jboss>

See A JMS client that interacts with the TextMDB. shows a variation of the P2P client that sends several messages to the "queue/B" destination and asynchronously receives the messages as modified by TextMDB from Queue A.

A JMS client that interacts with the TextMDB

package org.jboss.chap6.ex2;

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.Queue;

import javax.jms.QueueConnection;

import javax.jms.QueueConnectionFactory;

import javax.jms.QueueReceiver;

import javax.jms.QueueSender;

import javax.jms.QueueSession;

import javax.jms.TextMessage;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import EDU.oswego.cs.dl.util.concurrent.CountDown;

/** A complete JMS client example program that sends N

TextMessages to a Queue B and asynchronously receives the

messages as modified by TextMDB from Queue A.

@author Scott.Stark@jboss.org

@version $Revision:$

*/

public class SendRecvClient

{

static final int N = 10;

static CountDown done = new CountDown(N);

QueueConnection conn;

QueueSession session;

Queue queA;

Queue queB;

public static class ExListener implements MessageListener

{

public void onMessage(Message msg)

{

done.release();

TextMessage tm = (TextMessage) msg;

try

{

System.out.println("onMessage, recv text="+tm.getText());

}

catch(Throwable t)

{

t.printStackTrace();

}

}

}

public void setupPTP()

throws JMSException, NamingException

{

InitialContext iniCtx = new InitialContext();

Object tmp = iniCtx.lookup("ConnectionFactory");

QueueConnectionFactory qcf = (QueueConnectionFactory) tmp;

conn = qcf.createQueueConnection();

queA = (Queue) iniCtx.lookup("queue/A");

queB = (Queue) iniCtx.lookup("queue/B");

session = conn.createQueueSession(false,

QueueSession.AUTO_ACKNOWLEDGE);

conn.start();

}

public void sendRecvAsync(String textBase)

throws JMSException, NamingException, InterruptedException

{

System.out.println("Begin sendRecvAsync");

// Setup the PTP connection, session

setupPTP();

// Set the async listener for queA

QueueReceiver recv = session.createReceiver(queA);

recv.setMessageListener(new ExListener());

// Send a few text msgs to queB

QueueSender send = session.createSender(queB);

for(int m = 0; m < 10; m ++)

{

TextMessage tm = session.createTextMessage(textBase+"#"+m);

tm.setJMSReplyTo(queA);

send.send(tm);

System.out.println("sendRecvAsync, sent text="+tm.getText());

}

System.out.println("End sendRecvAsync");

}

public void stop() throws JMSException

{

conn.stop();

session.close();

conn.close();

}

public static void main(String args[]) throws Exception

{

System.out.println("Begin SendRecvClient,now="+System.currentTimeMillis());

SendRecvClient client = new SendRecvClient();

client.sendRecvAsync("A text msg");

client.done.acquire();

client.stop();

System.exit(0);

System.out.println("End SendRecvClient");

}

}

Run the client as follows:

[nr@toki examples]$ ant -Dchap=chap6 -Dex=2 run-example

Buildfile: build.xml

...

run-example2:

[copy] Copying 1 file to G:\JBoss\jboss-3.2.1\server\default\deploy

[echo] Waiting 5 seconds for deploy...

[java] Begin SendRecvClient, now=1056767530834

[java] Begin sendRecvAsync

[java] sendRecvAsync, sent text=A text msg#0

[java] sendRecvAsync, sent text=A text msg#1

[java] sendRecvAsync, sent text=A text msg#2

[java] sendRecvAsync, sent text=A text msg#3

[java] sendRecvAsync, sent text=A text msg#4

[java] sendRecvAsync, sent text=A text msg#5

[java] sendRecvAsync, sent text=A text msg#6

[java] sendRecvAsync, sent text=A text msg#7

[java] sendRecvAsync, sent text=A text msg#8

[java] sendRecvAsync, sent text=A text msg#9

[java] End sendRecvAsync

[java] onMessage, recv text=A text msg#2processed by: 23715584

[java] onMessage, recv text=A text msg#6processed by: 322649

[java] onMessage, recv text=A text msg#1processed by: 27534070

[java] onMessage, recv text=A text msg#3processed by: 23966866

[java] onMessage, recv text=A text msg#0processed by: 28532430

[java] onMessage, recv text=A text msg#4processed by: 1734943

[java] onMessage, recv text=A text msg#9processed by: 24814248

[java] onMessage, recv text=A text msg#7processed by: 21845470

[java] onMessage, recv text=A text msg#8processed by: 17243666

[java] onMessage, recv text=A text msg#5processed by: 403211

 

BUILD SUCCESSFUL

Total time: 9 seconds

The corresponding JBoss server console output is:

19:32:07,209 INFO [MainDeployer] Starting deployment of package: file:/G:/JBoss/jboss-3.2.1/server/default/deploy/chap6

-ex2.jar

19:32:07,760 INFO [EjbModule] Creating

19:32:07,770 INFO [EjbModule] Deploying TextMDB

19:32:07,810 INFO [MessageDrivenContainer] Creating

19:32:07,810 INFO [MessageDrivenInstancePool] Creating

19:32:07,810 INFO [MessageDrivenInstancePool] Created

19:32:07,810 INFO [JMSContainerInvoker] Creating

19:32:07,820 INFO [JMSContainerInvoker] Created

19:32:07,820 INFO [MessageDrivenContainer] Created

19:32:07,820 INFO [EjbModule] Created

19:32:07,820 INFO [EjbModule] Starting

19:32:07,820 INFO [MessageDrivenContainer] Starting

19:32:07,830 INFO [JMSContainerInvoker] Starting

19:32:07,830 INFO [DLQHandler] Creating

19:32:07,890 INFO [DLQHandler] Created

19:32:08,191 WARN [SecurityManager] No SecurityMetadadata was available for B adding default security conf

19:32:08,201 INFO [DLQHandler] Starting

19:32:08,201 INFO [DLQHandler] Started

19:32:08,201 INFO [JMSContainerInvoker] Started

19:32:08,201 INFO [MessageDrivenInstancePool] Starting

19:32:08,211 INFO [MessageDrivenInstancePool] Started

19:32:08,211 INFO [MessageDrivenContainer] Started

19:32:08,211 INFO [EjbModule] Started

19:32:08,211 INFO [EJBDeployer] Deployed: file:/G:/JBoss/jboss-3.2.1/server/default/deploy/chap6-ex2.jar

19:32:08,241 INFO [MainDeployer] Deployed package: file:/G:/JBoss/jboss-3.2.1/server/default/deploy/chap6-ex2.jar

19:32:12,136 WARN [SecurityManager] No SecurityMetadadata was available for A adding default security conf

19:32:12,206 INFO [TextMDB] TextMDB.ctor, this=28532430

19:32:12,216 INFO [TextMDB] TextMDB.ctor, this=27534070

19:32:12,307 INFO [TextMDB] TextMDB.ctor, this=23966866

19:32:12,307 INFO [TextMDB] TextMDB.ctor, this=23715584

19:32:12,307 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=27534070

19:32:12,307 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=28532430

19:32:12,347 INFO [TextMDB] TextMDB.ejbCreate, this=27534070

19:32:12,347 INFO [TextMDB] TextMDB.ejbCreate, this=28532430

19:32:12,347 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=23966866

19:32:12,357 INFO [TextMDB] TextMDB.ejbCreate, this=23966866

19:32:12,377 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=23715584

19:32:12,377 INFO [TextMDB] TextMDB.ejbCreate, this=23715584

19:32:12,387 INFO [TextMDB] TextMDB.ctor, this=1734943

19:32:12,387 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=1734943

19:32:12,387 INFO [TextMDB] TextMDB.ejbCreate, this=1734943

19:32:12,387 INFO [TextMDB] TextMDB.ctor, this=403211

19:32:12,387 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=403211

19:32:12,397 INFO [TextMDB] TextMDB.ejbCreate, this=403211

19:32:12,397 INFO [TextMDB] TextMDB.ctor, this=322649

19:32:12,397 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=322649

19:32:12,397 INFO [TextMDB] TextMDB.ejbCreate, this=322649

19:32:12,437 INFO [TextMDB] TextMDB.ctor, this=21845470

19:32:12,437 INFO [TextMDB] TextMDB.ctor, this=17243666

19:32:12,467 INFO [TextMDB] TextMDB.ctor, this=24814248

19:32:12,467 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=21845470

19:32:12,467 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=24814248

19:32:12,467 INFO [TextMDB] TextMDB.ejbCreate, this=24814248

19:32:12,477 INFO [TextMDB] TextMDB.ejbCreate, this=21845470

19:32:12,487 INFO [TextMDB] TextMDB.setMessageDrivenContext, this=17243666

19:32:12,487 INFO [TextMDB] TextMDB.ejbCreate, this=17243666

19:32:12,537 INFO [TextMDB] TextMDB.onMessage, this=28532430

19:32:12,537 INFO [TextMDB] TextMDB.sendReply, this=28532430, dest=QUEUE.A

19:32:12,537 INFO [TextMDB] TextMDB.onMessage, this=23715584

19:32:12,537 INFO [TextMDB] TextMDB.onMessage, this=23966866

19:32:12,537 INFO [TextMDB] TextMDB.onMessage, this=322649

19:32:12,547 INFO [TextMDB] TextMDB.onMessage, this=27534070

19:32:12,547 INFO [TextMDB] TextMDB.sendReply, this=23715584, dest=QUEUE.A

19:32:12,547 INFO [TextMDB] TextMDB.sendReply, this=23966866, dest=QUEUE.A

19:32:12,547 INFO [TextMDB] TextMDB.sendReply, this=322649, dest=QUEUE.A

19:32:12,567 INFO [TextMDB] TextMDB.sendReply, this=27534070, dest=QUEUE.A

19:32:12,647 INFO [TextMDB] TextMDB.onMessage, this=24814248

19:32:12,647 INFO [TextMDB] TextMDB.sendReply, this=24814248, dest=QUEUE.A

19:32:12,667 INFO [TextMDB] TextMDB.onMessage, this=1734943

19:32:12,677 INFO [TextMDB] TextMDB.sendReply, this=1734943, dest=QUEUE.A

19:32:12,687 INFO [TextMDB] TextMDB.onMessage, this=21845470

19:32:12,687 INFO [TextMDB] TextMDB.sendReply, this=21845470, dest=QUEUE.A

19:32:12,687 INFO [TextMDB] TextMDB.onMessage, this=17243666

19:32:12,697 INFO [TextMDB] TextMDB.onMessage, this=403211

19:32:12,727 INFO [TextMDB] TextMDB.sendReply, this=17243666, dest=QUEUE.A

19:32:12,727 INFO [TextMDB] TextMDB.sendReply, this=403211, dest=QUEUE.A

Items of note in this example include:

• The JMS client has no explicit knowledge that it is dealing with an MDB. The client simply uses the standard JMS APIs to send messages to a queue and receive messages from another queue.
• The MDB declares whether it will listen to a queue or topic in the ejb-jar.xml descriptor. The name of the queue or topic must be specified using a jboss.xml descriptor. In this example the MDB also sends messages to a JMS queue. MDBs may act as queue senders or topic publishers within their onMessage callback.
• The messages received by the client include a "processed by: NNN" suffix, where NNN is the hashCode value of the MDB instance that processed the message. This shows that many MDBs may actively process messages posted to a destination. Concurrent processing is one of the benefits of MDBs.

RMI IL (deprecated)

The first IL that was developed was based on Java's Remote Method Invocation (RMI). This is a robust IL since it is based on standard RMI technology, but it has a high overhead compared to other ILs and will likely be dropped in future releases.

NOTE: This IL will try to establish a TCP/IP socket from the server to the client. Therefore, clients that sit behind firewalls or have security restrictions prohibiting the use of SeverSockets should not use this IL.

OIL IL (deprecated)

The next IL that was developed was the "Optimized" IL (OIL). The OIL uses a custom TCP/IP protocol and serialization protocol that has very low overhead. This was the recommended socket based protocol until the addition of the UIL2 protocol.

NOTE: This IL will try to establish a TCP/IP socket from the server to the client. Therefore, clients that sit behind firewalls or have security restrictions prohibiting the use of SeverSockets should not use this IL.

UIL IL (deprecated)

The Unified Invocation Layer (UIL) was developed to allow clients that cannot have a connection created from the server back to the client due to firewall or other restrictions. It is almost identical to the OIL protocol except that a multiplexing layer is used to provide the bidirectional communication. The multiplexing layer creates two virtual sockets over one physical socket. This IL is slower than the OIL due to the higher overhead incurred by the multiplexing layer. This invocation layer is now deprecated in favor of UIL2.

UIL2 IL

The Unified version 2 Invocation Layer (UIL2) is a variation of the UIL protocol that also uses a single socket between the client and server. However, unlike all other socket based invocation layers like RMI, UIL and OIL which use a blocking round-trip message at the socket level, the UIL2 protocol uses true asynchronous send and receive messaging at the transport level. This provides for improved throughput and utilization and as such, it is the preferred socket invocation layer.

JVM IL

The Java Virtual Machine (JVM) Invocation Layer was developed to cut out the TCP/IP overhead when the JMS client is running in the same JVM as the server. This IL uses direct method calls for the server to service the client requests. This increases efficiency since no sockets are created and there is no need for the associated worker threads. This is the IL that should be used by Message Driven Beans (MDB) or any other component that runs in the same virtual machine as the server such as servlets, MBeans, or EJBs.

HTTP IL

The HTTP Invocation Layer (HTTPIL) allows for accessing the JBossMQ service over the HTTP or HTTPS protocols. This IL relies on the servlet deployed in the deploy/jms/jbossmq-httpil.sar to handle the http traffic. This IL is useful for access to JMS through a firewall when the only port allowed requires HTTP.

File PM

The File PM is a robust persistence manager that comes with JBossMQ. It creates separate directories for each of the destination created on the server, and stores each persistent message as a separate file in the appropriate directory. It has poor performance characteristics since it is frequently opening and closing files.

Rolling Logged PM

The Rolling Logged PM is also a file based persistence manager that has better performance than the File PM because it stores multiple messages in one file, reducing the overhead of opening/closing multiple files. This is a very fast PM but it is less transactionally reliable than the File PM due to its use of the FileOutputStream.flush() method call. On some operating systems/JVMs the FileOutputStream.flush() method does not guarantee that the data has been written to disk by the time the call returns.

JDBC2 PM

The JDBC2 PM is the second version of the original JDBC PM in JBossMQ 2.4.x. It has been substantially simplified and improved. This PM allows you to store persistent messages to a relational database using JDBC. The performance of this PM is directly related to the performance that can be obtained from the database. This PM has a very low memory overhead compared to the other persistence managers. Furthermore it is also highly integrated with the MessageCache to provide efficient persistence on a system that has a very active MessageCache.

Queues

Clients that are in the Point-to-Point paradigm typically use Queues. They expect that message sent to a Queue will be receive by only one other client once and only once. If multiple clients are receiving messages from a single queue, the messages will be load balanced across the receivers. Queue objects, by default, will be stored under the JNDI "queue/" sub context.

Topics

Topics are used in the Publish-Subscribe paradigm. When a client publishes a message to a topic, he expects that a copy of the message will be delivered to each client that has subscribed to the topic. Topic messages are delivered in the same manner a television show is delivered. Unless you have the TV on and are watching the show, you will miss it. Similarly, if the client is not up, running and receiving messages from the topics, it will miss messages published to the topic. To get around this problem of missing messages, clients can start a durable subscription. This is like having a VCR record a show you cannot watch at its scheduled time so that you can see what you missed when you turn your TV back on.

ClientSocketFactory: The javax.net.SocketFactory implementation class name to use on the client. If not specified the default factory will be obtained from javax.net.SocketFactory.getDefault() .

• SecurityDomain: Specify the security domain name to use with JBoss SSL aware socket factories. This is the JNDI name of the security manager implementation as described for the security-domain element of the jboss.xml and jboss-web.xml descriptors in Enabling Declarative Security in JBoss Revisited.

Configuring ILs for SSL

The UIL2 and OIL services support the use of SSL through custom socket factories that integrate JSSE using the security domain associated with the IL service. An example UIL2 service descriptor fragment that illustrates the use of the custom JBoss SSL socket factories is shown in See An example UIL2 config fragment for using SSL..