Redeployment & ClassCastException Part n..

[kalimero]

Problem with Redeployment of EJB. All files (Source & Binaries & build script are attached)

We are running jboss-3.2.1_tomcat-4.1.24 (default config)

JBoss: Release ID: JBoss [WonderLand] 3.2.1 (build: CVSTag=JBoss_3_2_1 date=200305041533)
Java: Java version: 1.4.1_02,Sun Microsystems Inc.


The demo is a simple servlet that makes a lookup on a Statless Session Bean. (see source)

1.) use ant to rebuild.
2.) prebuild versions are available in the /deploy folder
- test_servlet.war
- test_ejb.jar

3.) start JBoss and deploy test_servlet.war and test_ejb.jar
4.) http://localhost:8080/test_servlet/
The following output will occour:
08:51:58,006 ERROR [STDERR] ClassLoader lookup TestHome ----> org.jboss.mx.loading.UnifiedClassLoader3@99176f{ url=file:/C:/Programme/jboss/jboss-3.2.1_tomcat-4.1.24/server/default/tmp/deploy/server/default/deploy/test_ejb.jar/54.test_ejb.jar ,addedOrder=35}
08:51:58,006 ERROR [STDERR] ClassLoader TestHome in Servlet ----> org.jboss.mx.loading.UnifiedClassLoader3@99176f{ url=file:/C:/Programme/jboss/jboss-3.2.1_tomcat-4.1.24/server/default/tmp/deploy/server/default/deploy/test_ejb.jar/54.test_ejb.jar ,addedOrder=35}

fine and OK!


5.) Now make a redeployment of test_ejb.jar without deploying test_servlet.jar
6.) Call again http://localhost:8080/test_servlet/
The following output will occour:

08:53:16,088 INFO [MainDeployer] Deployed package: file:/C:/Programme/jboss/jboss-3.2.1_tomcat-4.1.24/server/default/deploy/test_ejb.jar

08:53:19,803 ERROR [STDERR] ClassLoader lookup TestHome ----> org.jboss.mx.loading.UnifiedClassLoader3@185e90f{ url=file:/C:/Programme/jboss/jboss-3.2.1_tomcat-4.1.24/server/default/tmp/deploy/server/default/deploy/test_ejb.jar/56.test_ejb.jar ,addedOrder=37}
08:53:19,813 ERROR [STDERR] ClassLoader TestHome in Servlet ----> org.jboss.mx.loading.UnifiedClassLoader3@99176f{ url=file:/C:/Programme/jboss/jboss-3.2.1_tomcat-4.1.24/server/default/tmp/deploy/server/default/deploy/test_ejb.jar/54.test_ejb.jar ,addedOrder=35}

08:53:19,813 ERROR [STDERR] java.lang.ClassCastException
08:53:19,813 ERROR [STDERR] at at.creato.test.web.TestServlet.doGetPost(Test
Servlet.java:36)
....

How can we solve this problem?

greetings
Wolfgang


As I am not able to attach the zip file containing sources and binaries (zipped 20 kb) i just put it on a server outside... :
http://www.creato.at/jboss_forum/jboss3.2.x-test.zip

[adrian.brock]

You must redeploy the servlet because it
is still holding a reference to the ejb interfaces
from the previous instances.

Alternatively, separate the interfaces into a
separate jar and put them server/default/lib

That way you can redeploy either implementation
without worrying about contract redeployments

Regards,
Adrian

[kalimero]

Yes, I know i have to redeploy the servlet... but this we don't want :-)) (jboss 2.4.x you can deploy the ejb without redeploying the ear or war...)

To put it in the lib is not really a solution, because you kick off the redeployment feature (especially if using clustering...)

The Problem:
We have some EJBs and perhaps 20 - 30 different ears using the same business logic... hm...

So if we redeploy the ebj(s) we have to redeploy all ears... and that's not really the solution.

At this moment we are using reflection to call the ejbs (so we need not to cast to the corresponding Home and Remote Interface) but if use dataobject as Parameters or Return values -> reflection is not really the solution...

Perhaps we'll try a hack at the UCL for flushing the interfaces or something like that.

I just wanna know if somebody had similar problems...

Thx.
Wolfgang

[adrian.brock]

If you want something similar to 2.4,
you can use a loader repository for each deployment
and use the ByValueInvokerInterceptor.

All objects are then serialized between the
caller and callee. It is much slower.

The class has already been flushed from the UCL.
The problem is you webapps are holding onto them.

Regards,
Adrian

[emdevlin]

Adrian,

I'm using jdk 1.3.1, jboss 3.0.8, tomcat 4.1.24,

I think I have a similar problem, but it is manifesting itself as a NoSuchMethodException. I thought that if I did an InitialContext.lookup that I would get the latest proxy class which would then allow me to do the reflection correctly. I'm not able to do the reflection unless I start and stop the web app. Does JBoss update the proxies held by the war if not then the only way must be through the ByValueInvokerInterceptor you mentioned above.

bean deploys
war deploys
war refrences bean
bean redeploys with changed methods
war goes boom

Thanks
Eric