Error during Class Loading in jboss 4.2.1

[ckanani]

Hi All,

i have 3 different applications (3 ear) for my project.

all 3 ears have some common user defined jars.so when i run my application it gives me following error:

java.lang.LinkageError: loader constraint violation: when resolving interface method "com.atreus.serviceinstances.bvoipactivator.customer.BusinessCustomerServiceValue.setFeaturePackageInputData(Lcom/atreus/buildingblocks/omegacommon/datamodel/FeaturePackageInputData;)V" the class loader (instance of org/jboss/web/tomcat/service/WebAppClassLoader) of the current class, com/atreus/serviceinstances/bvoipactivator/provisioning/ProvisioningUtils, and the class loader (instance of org/jboss/mx/loading/UnifiedClassLoader3) for resolved class, com/atreus/serviceinstances/bvoipactivator/customer/BusinessCustomerServiceValue, have different Class objects for the type com/atreus/buildingblocks/omegacommon/datamodel/FeaturePackageInputData used in the signature

        at com.atreus.serviceinstances.bvoipactivator.provisioning.ProvisioningUtils.populateCustomerServiceValue(ProvisioningUtils.java:112)

        at com.atreus.serviceinstances.bvoipactivator.provisioning.ProvisioningPortalInterface.createCustomer(ProvisioningPortalInterface.java:173)

        at com.atreus.serviceinstances.bvoipactivator.actions.ProvisioningAction.createCustomer(ProvisioningAction.java:218)

        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:597)

        at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:276)

i am new to jboss, so any one has any idea what could be the solution?

Thanks.

[wdfink]

As I do not know the details of your deployment (e.g. class loader isolation and where the classes packed)

I'll give you a few information in general.

By default JBoss will load all jar/ear files in lib or deploy with one classloader except WAR files, this is a bit different.

If you look into your error message you find that the classes are loaded from WebAppClassLoader and UnifiedClassLoader3.

If you have packed the same class file into a WebApp and a EJBApp it will be loaded by a different ClassLoader.

If you using it and have calls between the different Apps containing such classes the JVM is not able to handle it.

See

http://community.jboss.org/wiki/JBossClassLoadingUseCases

http://community.jboss.org/wiki/ClassLoadingOverview

http://community.jboss.org/wiki/ClassLoadingConfiguration

The solution can be

- use call-by-value (performance drawback)

- move such classes as library into the servers lib folder and remove from EAR

[wdfink]

Call-by-value vs. call-by-reference is discussed here => http://community.jboss.org/thread/147418