Ear Sar ClassLoader related Problems

[shreedharn]

Hi guys,

Am in the process of porting my application from JBoss3.0 to JBoss3.2. And no surprise I am having lots of class loader related problem. It wud be gr8 help if somebody could find out where I had gone wrong.

I have ear and a sar for my application. EJB/Web stuffs are packed in the ear and my services are packed in sar. There are few classes that are duplicated in both the archives which gives a lot of ClassLoader related problem.

When deployed as is [myapp.ear and myapp.sar copied to deploy directory], it gives a LinkageError stating that there are duplicate classes.

I tried to define the class loader scope for ear (using <loader-repository> in jboss-app.xml), but when any of service class accesses the ejb, it gives a classcast exception when casting EJB Home. Then I used ByValueInvokerInterceptor to avoid call by reference mode. (courtesy http://www.mail-archive.com/[e-mail]/msg37149.html//www.mail-archive.com/[e-mail]/msg37149.html), after which I am able to successfully look up. But calling a finder (on the looked up home) leads to a NullPointerException! (see stack trace at the end of posting)

Then I tried providing same value in <loader-repository> in jboss-app.xml of both ear and sar. Still there was a ClassCastException during Home look up!!

Any clues will be highly helpful.

Thanks,
Shreedhar


java.lang.NullPointerException
at org.jboss.ejb.EntityContainer$ContainerInterceptor.invokeHome(EntityC
ontainer.java:994)
at org.jboss.ejb.plugins.AbstractInterceptor.invokeHome(AbstractIntercep
tor.java:88)
at org.jboss.ejb.plugins.EntitySynchronizationInterceptor.invokeHome(Ent
itySynchronizationInterceptor.java:188)
at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invo
keHome(CachedConnectionInterceptor.java:215)
at org.jboss.ejb.plugins.AbstractInterceptor.invokeHome(AbstractIntercep
tor.java:88)
at org.jboss.ejb.plugins.EntityInstanceInterceptor.invokeHome(EntityInst
anceInterceptor.java:91)
at org.jboss.ejb.plugins.EntityLockInterceptor.invokeHome(EntityLockInte
rceptor.java:61)
at org.jboss.ejb.plugins.EntityCreationInterceptor.invokeHome(EntityCrea
tionInterceptor.java:28)
at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInte
rceptor.java:88)
at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxIntercep
torCMT.java:243)
at org.jboss.ejb.plugins.TxInterceptorCMT.invokeHome(TxInterceptorCMT.ja
va:74)
at org.jboss.ejb.plugins.SecurityInterceptor.invokeHome(SecurityIntercep
tor.java:92)
at org.jboss.ejb.plugins.LogInterceptor.invokeHome(LogInterceptor.java:1
20)
at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invokeHome(ProxyF
actoryFinderInterceptor.java:93)
at org.jboss.ejb.EntityContainer.internalInvokeHome(EntityContainer.java
:477)
at org.jboss.ejb.Container.invoke(Container.java:694)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBea
nDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:549)
at org.jboss.invocation.local.LocalInvoker.invoke(LocalInvoker.java:101)

at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.jav
a:83)
at org.jboss.proxy.TransactionInterceptor.invoke(TransactionInterceptor.
java:46)
at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:4
5)
at org.jboss.proxy.ejb.HomeInterceptor.invoke(HomeInterceptor.java:173)
at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:85)
at $Proxy106.findByPrimaryKey(Unknown Source)

[adrian.brock]

If you don't want to share classes between deployments,
you need to use the ByValueInvokerInterceptor rather than
the InvokerInterceptor and useRemote interfaces.

This makes remote interfaces use Pass By Value inside the
same VM (about 10x slower)

Regards,
Adrian

[shreedharn]

Hi Adrian,

I wud like to ideally share the classes between deployments. i.e. SAR(service archive for our application) and EAR. But since there are classes duplicated in the SAR and EAR, I get linkage error(DuplicateClassException) during EAR deployment.
Is there any better way to solve this problem? or should I pack in such a way that the classes are not duplicated in the archives.

Add. Info:
(1)Initially I was using app-service.xml instead of SAR. I moved to SAR hoping that I could have more control over classloader by using jboss-app.xml.

(2) My deployment structure -
deploy/app.sar
deploy/app.ear

Thanks,
Shreedhar Natarajan

[adrian.brock]

We don't have support for class dependencies.

The sar will be loaded before the ear, so putting the classes in the
sar will work.

If you redeploy the sar, make sure you redeploy the ear.

Alternatively, statically deploy the shared classes in
server/default/lib

Regards,
Adrian

[asubu]

Hi,
I am also facing a similar problem, when JBOSS starts the MBEAN is trying to look up an entity bean and I get the following exception. Can anyone help me here?

ava.lang.NullPointerException
at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.createBeanClassInstance(JDBCStoreManager.java:555)
at org.jboss.ejb.plugins.CMPPersistenceManager.createBeanClassInstance(CMPPersistenceManager.java:137)
at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.createBeanClassInstance(CachedConnectionInterceptor.java:
at org.jboss.ejb.EntityContainer.createBeanClassInstance(EntityContainer.java:226)
at org.jboss.ejb.plugins.AbstractInstancePool.get(AbstractInstancePool.java:146)
at org.jboss.ejb.plugins.EntityInstanceInterceptor.invokeHome(EntityInstanceInterceptor.java:79)
at org.jboss.ejb.plugins.EntityLockInterceptor.invokeHome(EntityLockInterceptor.java:61)
at org.jboss.ejb.plugins.EntityCreationInterceptor.invokeHome(EntityCreationInterceptor.java:28)
at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:88)
at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:243)
at org.jboss.ejb.plugins.TxInterceptorCMT.invokeHome(TxInterceptorCMT.java:74)
at org.jboss.ejb.plugins.SecurityInterceptor.invokeHome(SecurityInterceptor.java:92)
at org.jboss.ejb.plugins.LogInterceptor.invokeHome(LogInterceptor.java:120)
at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invokeHome(ProxyFactoryFinderInterceptor.java:93)
at org.jboss.ejb.EntityContainer.internalInvokeHome(EntityContainer.java:477)
at org.jboss.ejb.Container.invoke(Container.java:694)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBeanDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:549)
at org.jboss.invocation.local.LocalInvoker.invoke(LocalInvoker.java:101)
at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.java:83)
at org.jboss.proxy.TransactionInterceptor.invoke(TransactionInterceptor.java:46)
at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:45)
at org.jboss.proxy.ejb.HomeInterceptor.invoke(HomeInterceptor.java:173)
at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:85)