Re: ClassCastException w/ tomcat & JND

[James Strachan <ja...@gmail.com>]

Sounds like you've multiple jms API jars causing the
ClassCastException (ActiveMQConnectionFactory definitely is-a
ConnectionFactory :)

On 6/15/07, Rob Terpilowski <rt...@yahoo.com> wrote:
> Hello active mq users ,
> I am running into the following issue that was posted on the mailing list in January, but for which no
> response was posted.
>
> I have the following configuration on my system
>
> tomcat 5.5
>
> java 1.5.09
>
> activemq jars version 4.1.1
>
> The active MQ broker is started  , from the application .
>
> the code for it is
>
> public void contextInitialized(ServletContextEvent arg0) {
>
> try{
>
> System.out.println("Starting ActiveMQ Broker Service...");
>
> broker.addConnector("tcp://localhost:61616?trace=true");
>
> broker.start();
>
> System.out.println("Active MQ Broker Started at local host port 61616");
>
> }catch(Exception e){
>
> System.err.println(e.getMessage());
>
> e.printStackTrace();
>
> throw new RuntimeException(e);
>
> }
>
> }
>
>
>
> In server.xml , I placed the JNDI resources as follows
> <GlobalNamingResources>
>
> <Resource name="jms/TopicConnectionFactory"
>
> auth="Container"
>
> type="org.apache.activemq.ActiveMQConnectionFactory"
>
> description="JMS Connection Factory"
>
> factory="org.apache.activemq.jndi.JNDIReferenceFactory"
>
> brokerURL="tcp://localhost:61716"
>
> brokerName="LocalActiveMQBroker"/>
>
> <Resource name="jms/Topic"
>
> auth="Container"
>
> type="org.apache.activemq.command.ActiveMQTopic"
>
> description="sample Topic"
>
> factory="org.apache.activemq.jndi.JNDIReferenceFactory"
>
> physicalName="FOO.BAR"/>
>
> </GlobalNamingResources>
>
> I have a web app called UI , I am trying to access these global jndi
> recources from this web app, Hence the context.xml for this web app has
> the following
>
> <Context reloadable="true">
>
> <ResourceLink
> name="ConnectionFactory"global="jms/TopicConnectionFactory" type=
> "org.apache.activemq.ActiveMQConnectionFactory" />
>
> <ResourceLink name="PNMTopic" global="jms/Topic" type=
> "org.apache.activemq.command.ActiveMQTopic" />
>
> </Context>
>
> The subsciber class in the UI context is as follows
>
> public class PNMSubscriber {
>
> TopicConnection tConn ;
>
> TopicConnectionFactory tFactory ;
>
> Topic pnmTopic;
>
> ActiveMQTopicSession pnmSession ;
>
> public PNMSubscriber(){
>
> try{
>
> InitialContext initialContext = new InitialContext();
>
> Context envContext = (Context) initialContext.lookup("java:comp/env");
>
> tFactory
> =(TopicConnectionFactory)envContext.lookup("ConnectionFactory");
>
> tConn = tFactory.createTopicConnection();
>
> pnmSession = (ActiveMQTopicSession) tConn.createTopicSession(true,
> Session.AUTO_ACKNOWLEDGE);
>
> pnmTopic = (Topic)envContext.lookup("PNMTopic");
>
> pnmSubscriber = pnmSession.createSubscriber(pnmTopic);
>
> }catch(Exception e){
>
> e.printStackTrace();
>
> }
>
> }
>
> I get a class cast exception as follows
>
> java.lang.ClassCastException:
> org.apache.activemq.ActiveMQConnectionFactory
>
> at
> com.cpnm.common.messaging.PNMSubscriber.<init>(PNMSubscriber.java:40)
>
> The exception is raised , at the following line , in the code above.
>
> tFactory =
> (TopicConnectionFactory)envContext.lookup("ConnectionFactory");
>
> I tried casting the object to "ActiveMQConnectionFactory" , I still get
> the same exception.
>
> I think, Iam missing something in the configuration, please let me know,
> if I need to add anything else.
>
> The active MQ jars are located in <catalina-home>/server/lib and I tried putting them
> under <catalina-home>/shared/lib as well with no difference
>
> thank you,
> -rob
>
>
>
>
>
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-- 
James
-------
http://macstrac.blogspot.com/