HELP!! ClassCastException with custom module classloader hierarchy and redeployment

Question

Hi,
I am defining custom module classloader hierarchy to avoid redeploying of the
entire application mainly because we have so many EJBs and it takes a long time
to deploy the entire app. I deploy my app using the exploded directory, add a
new method to an EJB in my dal.jar, redeploy, run my unittest and I get ClassCastException.
I am using weblogic.Deployer utility to reploy my module using "-targets dal.jar@accsserver"
argument. I even tried undeploying that module and redeploy again with no luck.
here is weblogic-application.xml definition of the custom class loader
<classloader-structure>
<module-ref>
     <module-uri>floghmi.war</module-uri>
     </module-ref>
<module-ref>
     <module-uri>cts.jar</module-uri>
     </module-ref>
<module-ref>
     <module-uri>fdbs.jar</module-uri>
     </module-ref>
<classloader-structure>
     <module-ref>
          <module-uri>dml.jar</module-uri>
     </module-ref>
<classloader-structure>
     <module-ref>
     <module-uri>dal.jar</module-uri>
</module-ref>
</classloader-structure>
</classloader-structure>
</classloader-structure>
thanks,
Nasrin

Answer 1

Rob,
regarding your question on redeploying the whole app without the classloader
structure, yes, that works fine. If I change a class and redeploy the whole app,
things are ok. However, when I speocify the classloader structure, and try to
redeploy the dal.jar, I get ClassClasException.
You are right about dml.jar being in a separate classloader. I have changed my
structure after I posted my question to load dml.jar from the application classloader.
So Rob, is there a bug in Weblogic 8.1 that causes this exception?
please let me know, I am anxiously waiting your response.
thanks,
Nasrin
Rob Woollen <[email protected]> wrote:
>
>
Nasrin Azordegan wrote:
Rob,
if I remove my classloader structure from weblogic-application.xml,I get an
error during redeployment, saying "You must include all of<list ofmy module names
here> in your files list to modify <dal.jar>. Yes, the server enforces constraints on partial redeployments. You must
deploy all the modules in a given classloader and any modules in child
classloaders.
Just to make sure, if you initially deploy your app, or redeploy the
whole thing, it works fine without the classloader-structure, right?
The problem I am trying to solve is to minimize our deployment time.Our application
has over 700 CMP 2.0 entity beans and 200 session beans. Our applicationdeployment
follows the J2EE layer architecture. The data mapping layer which consistof 700
entity beans are located in dml.jar. The data access layer which consistof 200
session beans are located in dal.jar. We create our ear with thesetwo jar files
plus some other framework jars and deploy on bea weblogic 8.1 SP2 andthat takes
about an hour. I need to be able to modify a session bean, i.e. changethe implementation
of a session bean or add a new method to a session bean interface andredeploy
only data access layer, the dal.jar, not the entity beans. This explainswhy you
see dml.jar in a classloader with a child classloader that loads dal.jar.
I included the ClassCastException from weblogic server console below.What is
happening is that I have a session bean with 6 methods that just doesa println.
I deploy my session bean, ExerciseSessionBeanFactory, and run my unittest that
invokes test1 through test6 methods. I modify my bean to add "test7"method and
redeply dal.jar successfully. I run my unit test that invokes test1through test7
methods and then I get a ClassCastException.
I hope this helps. Please let me know if you need more details.If you push dml.jar into a subloader, that means you can change dml.jar
without touching anything in the parent loader. However, it also means
that you've isolated it's classes and other modules can't see them.
-- Rob
thanks,
Nasrin
in test method
in test2 method
in test3 method
in test4 method
in test5 method
in test6 method
<Apr 12, 2004 9:26:03 AM PDT> <Warning> <EJB> <BEA-010096> <The Message-Driven
EJB: SimTimeListener is unable to connect
to the JMS destination: cn=t.cms.cts.simTimeInfo. Connection failedafter 184
attempts. The MDB will attempt to reconne
ct every 10 seconds. This log message will repeat every 600 secondsuntil the
condition clears.>
<Apr 12, 2004 9:26:03 AM PDT> <Warning> <EJB> <BEA-010061> <The Message-Driven
EJB: SimTimeListener is unable to connect
to the JMS destination: cn=t.cms.cts.simTimeInfo. The Error was:
[EJB:011011]The Message-Driven EJB attempted to connect to the JMSdestination
with the JNDI name: cn=t.cms.cts.simTimeI
nfo. However, the object with the JNDI name: cn=t.cms.cts.simTimeInfois not a
JMS destination, or the destination found
was of the wrong type (Topic or Queue).>
in test method
in test2 method
in test3 method
in test4 method
in test5 method
in test6 method
<Apr 12, 2004 9:28:26 AM PDT> <Warning> <RMI> <BEA-080003> <RuntimeExceptionthrown
by rmi server: com.trs.cv.infr.istr.
sc.sim.factory.ejb.ExerciseSessionFactory_zhotso_EOImpl.test7()
java.lang.ClassCastException.
java.lang.ClassCastException
at com.trs.cv.infr.istr.sc.sim.factory.ejb.ExerciseSessionFactory_zhotso_EOImpl_WLSkel.invoke(Unknown
Source)
at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:477)
at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerRef.java:108)
at weblogic.rmi.internal.BasicServerRef$1.run(BasicServerRef.java:420)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:353)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:144)
at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:415)
at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest.java:30)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
Rob Woollen <[email protected]> wrote:
You'll have to give me some more information on the ClassCastException.
Where does it happen? Print out the classnames and the
classloaders of the 2 objects.
Does everything work fine if you remove your classloader-structure?
-- Rob
Nasrin Azordegan wrote:
Hi,
I am defining custom module classloader hierarchy to avoid redeployingof the
entire application mainly because we have so many EJBs and it takesa long time
to deploy the entire app. I deploy my app using the exploded directory,add a
new method to an EJB in my dal.jar, redeploy, run my unittest and
I
get ClassCastException.
I am using weblogic.Deployer utility to reploy my module using "-targetsdal.jar@accsserver"
argument. I even tried undeploying that module and redeploy again
with
no luck.
here is weblogic-application.xml definition of the custom class loader
<classloader-structure>
<module-ref>
     <module-uri>floghmi.war</module-uri>
     </module-ref>
<module-ref>
     <module-uri>cts.jar</module-uri>
     </module-ref>
<module-ref>
     <module-uri>fdbs.jar</module-uri>
     </module-ref>
<classloader-structure>
     <module-ref>
          <module-uri>dml.jar</module-uri>
     </module-ref>
<classloader-structure>
     <module-ref>
     <module-uri>dal.jar</module-uri>
</module-ref>
</classloader-structure>
</classloader-structure>
</classloader-structure>
thanks,
Nasrin