ActiveMQ Users
We are exploring the use of ActiveMQ as part of our IT infrastructure
but have run into some difficulties connecting to a standalone AMQ
server from Tomcat 5.5.15 with both the 4.0 release and the May 8th
2006 build (on MacOS X, JVM 1.5, using Struts 1.2.9). Using the
latter, I've added incubator-activemq-4.0.jar to $CATALINA_HOME/
common/lib, included it in my class path, and added the following code:
<< in META-INF/context.xml >>
<Context antiJARLocking="true">
<Resource
name="jms/ConnectionFactory"
auth="Container"
type="org.apache.activemq.ActiveMQConnectionFactory"
description="JMS Connection Factory"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
brokerURL="tcp://localhost:61616"
brokerName="LocalActiveMQBroker"
useEmbeddedBroker="false"/>
<Resource name="jms/someTopic"
auth="Container"
type="org.apache.activemq.command.ActiveMQTopic"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
physicalName="TEST_TOPIC.FOO"/>
<Resource name="jms/aQueue"
auth="Container"
type="org.apache.activemq.command.ActiveMQQueue"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
physicalName="TEST.FOO"/>
</Context>
<< in my struts action class >>
Context initContext = new InitialContext();
Context envContext = (Context) initContext.lookup("java:comp/env");
ActiveMQConnectionFactory connectionFactory =
(ActiveMQConnectionFactory) envContext.lookup("jms/ConnectionFactory");
ActiveMQConnection connection = (ActiveMQConnection)
connectionFactory.createConnection();
connection.start();
ActiveMQSession session = (ActiveMQSession) connection.createSession
(false, Session.AUTO_ACKNOWLEDGE);
ActiveMQDestination dest = (ActiveMQDestination) session.createQueue
("TEST.FOO");
ActiveMQMessageProducer producer = (ActiveMQMessageProducer)
session.createProducer(dest); /* throws Threw Error
java.lang.LinkageError: loader constraints violated when linking
javax/jms/Destination */
producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
ActiveMQTextMessage message = (ActiveMQTextMessage)
session.createTextMessage("Struts Action Sent This Message");
producer.send(message);
session.close();
connection.close();
The result is that session.createProducer(dest) throws 'Error
java.lang.LinkageError: loader constraints violated when linking
javax/jms/Destination'. I've spent several days tracking down javax/
jms/Destination declarations in jars on my classpath and removing
them but continue to get the same result. I've also tried declaring
my ActiveMQXxx variables as the javax/jms superclass of each, as in
many of the examples I've seen, but get ClassCastExceptions on the
connection factory lookup. ActiveMQ would be great addition to our
infrastructure so I'm hopeful that someone knows of a solution to
this little bump in the road.
Thanks in Advance,
Brad Steiner
Senior Software Engineer
The GreaterGood Network
