3 Replies Latest reply on Feb 12, 2006 2:05 PM by Flush

    problem with JBoss class loading

    Omid Saadati Newbie

      Hi
      I have an EAR file with one war and one EJB jar on it. the tow module share some third party jars and shared classes so here are highlights of how I have it structured.

      MyEAR.ear
      -META-INF/application.xml
      -META-INF/jboss-app.xml <----- used it for isolated hierchial class repository
      -lib/*.jar <---- shared libs
      -classes/ <----- shared classes
      -MyWAR.war
      --META-INF/MANIFEST.MF <----- used Class-Path to point to lib/*jar and claases/
      --WEB-INF

      -MYEBJ.jar
      --META-INF/MANFIEST.MF <---- used Class-Path to point to lib/*jar and classes/
      ....

      Now in the lib/ directory we have our own versions of commons-logging.jar and log4j.jar and in classes/ directory we have a commons-logging.property file with the following content
      org.apache.commons.logging.LogFactory = com.wagerworks....WWLogFactory
      and class 'com.wagerworks....WWLogFactory' is inside classes/ directory

      Now the TomcatDeployer throws NoClassFoundException with the following trace.

      [EARDeployer] Init J2EE application: file:/C:/Program Files/jboss-4.0.3SP1/server/mercury/deploy/WagerWorks.ear/
      12:08:49,267 INFO [TomcatDeployer] deploy, ctxPath=/mercury, warUrl=.../deploy/WagerWorks.ear/WagerWare.war/
      12:08:50,127 ERROR [Digester] Begin event threw exception
      org.apache.commons.logging.LogConfigurationException: java.lang.ClassNotFoundException: No ClassLoaders found for: com.wagerworks.mercury.common.startup.WWLogFactory

      at org.apache.commons.logging.LogFactory$2.run(LogFactory.java:612)
      at java.security.AccessController.doPrivileged(Native Method)
      at org.apache.commons.logging.LogFactory.newFactory(LogFactory.java:564)
      at org.apache.commons.logging.LogFactory.getFactory(LogFactory.java:355)
      at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:398)
      at org.apache.catalina.session.ManagerBase.(ManagerBase.java:63)
      at org.apache.catalina.session.StandardManager.(StandardManager.java:64)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
      at java.lang.reflect.Constructor.newInstance(Constructor.java:274)
      at java.lang.Class.newInstance0(Class.java:306)
      at java.lang.Class.newInstance(Class.java:259)
      at org.apache.tomcat.util.digester.ObjectCreateRule.begin(ObjectCreateRule.java:205)
      at org.apache.tomcat.util.digester.Rule.begin(Rule.java:152)
      at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1275)
      at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
      at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
      at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
      at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
      at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
      at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
      at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
      at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1561)
      at org.apache.catalina.startup.ContextConfig.processContextConfig(ContextConfig.java:778)
      at org.apache.catalina.startup.ContextConfig.contextConfig(ContextConfig.java:714)
      at org.apache.catalina.startup.ContextConfig.init(ContextConfig.java:974)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:273)
      at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
      at org.apache.catalina.core.StandardContext.init(StandardContext.java:5019)
      at org.apache.catalina.core.StandardContext.start(StandardContext.java:3885)
      at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:759)
      at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:739)
      at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:524)
      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.apache.commons.modeler.BaseModelMBean.invoke(BaseModelMBean.java:503)
      at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:150)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.apache.catalina.core.StandardContext.init(StandardContext.java:5005)
      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.apache.commons.modeler.BaseModelMBean.invoke(BaseModelMBean.java:503)
      at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:150)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.web.tomcat.tc5.TomcatDeployer.performDeployInternal(TomcatDeployer.java:280)
      at org.jboss.web.tomcat.tc5.TomcatDeployer.performDeploy(TomcatDeployer.java:88)
      at org.jboss.web.AbstractWebDeployer.start(AbstractWebDeployer.java:357)
      at org.jboss.web.WebModule.startModule(WebModule.java:68)
      at org.jboss.web.WebModule.startService(WebModule.java:46)
      at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:274)
      at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:230)
      at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:324)
      at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceController.java:943)
      at $Proxy0.start(Unknown Source)
      at org.jboss.system.ServiceController.start(ServiceController.java:428)
      at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:324)
      at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:176)
      at $Proxy38.start(Unknown Source)
      at org.jboss.web.AbstractWebContainer.start(AbstractWebContainer.java:400)
      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.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:118)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:127)
      at org.jboss.mx.interceptor.DynamicInterceptor.invoke(DynamicInterceptor.java:80)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:176)
      at $Proxy39.start(Unknown Source)
      at org.jboss.deployment.MainDeployer.start(MainDeployer.java:989)
      at org.jboss.deployment.MainDeployer.start(MainDeployer.java:979)
      at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:790)
      at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:753)
      at sun.reflect.GeneratedMethodAccessor10.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:324)
      at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:118)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:127)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:176)
      at $Proxy6.deploy(Unknown Source)
      at org.jboss.deployment.scanner.URLDeploymentScanner.deploy(URLDeploymentScanner.java:319)
      at org.jboss.deployment.scanner.URLDeploymentScanner.scan(URLDeploymentScanner.java:507)
      at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.doScan(AbstractDeploymentScanner.java:192)
      at org.jboss.deployment.scanner.AbstractDeploymentScanner.startService(AbstractDeploymentScanner.java:265)
      at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:274)
      at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:230)
      at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:324)
      at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceController.java:943)
      at $Proxy0.start(Unknown Source)
      at org.jboss.system.ServiceController.start(ServiceController.java:428)
      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.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:176)
      at $Proxy4.start(Unknown Source)
      at org.jboss.deployment.SARDeployer.start(SARDeployer.java:285)
      at org.jboss.deployment.MainDeployer.start(MainDeployer.java:989)
      at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:790)
      at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:753)
      at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:737)
      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.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
      at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
      at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:118)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:127)
      at org.jboss.mx.server.Invocation.invoke(Invocation.java:74)
      at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
      at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
      at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:176)
      at $Proxy5.deploy(Unknown Source)
      at org.jboss.system.server.ServerImpl.doStart(ServerImpl.java:453)
      at org.jboss.system.server.ServerImpl.start(ServerImpl.java:330)
      at org.jboss.Main.boot(Main.java:187)
      at org.jboss.Main$1.run(Main.java:438)
      at java.lang.Thread.run(Thread.java:536)
      Caused by: java.lang.ClassNotFoundException: No ClassLoaders found for: com.wagerworks.mercury.common.startup.WWLogFactory
      at org.jboss.mx.loading.LoadMgr3.beginLoadTask(LoadMgr3.java:198)
      at org.jboss.mx.loading.RepositoryClassLoader.loadClassImpl(RepositoryClassLoader.java:475)
      at org.jboss.mx.loading.RepositoryClassLoader.loadClass(RepositoryClassLoader.java:377)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:255)
      at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:315)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:140)
      at org.apache.commons.logging.LogFactory$2.run(LogFactory.java:610)
      ... 164 more
      12:08:50,142 ERROR [ContextConfig] Parse error in default web.xml
      org.apache.commons.logging.LogConfigurationException: java.lang.ClassNotFoundException: No ClassLoaders found for: com.wagerworks.mercury.common.startup.WWLogFactory
      at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2719)
      at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2745)
      at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1278)
      at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
      at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
      at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
      at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
      at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
      at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
      at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)

      any idea would be appreciated... i have tired various classLoading configurations and none seems to work. the only way I can get it to work is to jar up classes/ directory and put it under server/defaul/lib directory.
      but I am sure there should be a better way to do that. since classes/ should only be visible for my EAR file.
      I am using JBoss 4.0.3SP1
      thanks

        • 1. Re: problem with JBoss class loading
          Toison Guillaume Newbie

          In almost all my projetcts I user the following packaging structure and it works fine :

          - All JARs, WARs, SARs... at EAR root level
          - Nothing classpath related in MANIFEST.MFs
          - All modules are in the application.xml eg :

           <module>
           <java>3rd-party.jar</java>
           </module>
          


          • 2. Re: problem with JBoss class loading
            Flush Newbie

            I was posting a similar problem. I think it has to do with the deployment-based scoping. This is my scenario:

            App1.ear -> Contains a session bean, registered in JNDI
            App2.ear -> Contains a session bean, registered in JNDI, which retrieves and invokes a business method on session bean of App1

            If I package the two ears without jboss-app.xml, App2 can happily lookup session bean on app1 and invoke its business method. If I package the two apps with jboss-app.xml, I get the following exception:


            18:19:10,671 ERROR [LogInterceptor] RuntimeException in method: public abstract void uk.co.jemos.ucltest2.intf.Session2Session.executeUcl1HelloWorld() throws java.rmi.RemoteException:
            java.lang.ClassCastException
            at com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:229)
            at javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
            at uk.co.jemos.ucltest2.ejbs.sessions.Session2Bean.executeUcl1HelloWorld(Session2Bean.java:79)
            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:585)
            at org.jboss.invocation.Invocation.performCall(Invocation.java:345)
            at org.jboss.ejb.StatelessSessionContainer$ContainerInterceptor.invoke(StatelessSessionContainer.java:214)
            at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:149)
            at org.jboss.ejb.plugins.StatelessSessionInstanceInterceptor.invoke(StatelessSessionInstanceInterceptor.java:154)
            at org.jboss.webservice.server.ServiceEndpointInterceptor.invoke(ServiceEndpointInterceptor.java:54)
            at org.jboss.ejb.plugins.CallValidationInterceptor.invoke(CallValidationInterceptor.java:48)
            at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:106)
            at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:335)
            at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:166)
            at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:153)
            at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:192)
            at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:122)
            at org.jboss.ejb.SessionContainer.internalInvoke(SessionContainer.java:624)
            at org.jboss.ejb.Container.invoke(Container.java:873)
            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:585)
            at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
            at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
            at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
            at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
            at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
            at org.jboss.invocation.jrmp.server.JRMPInvoker$MBeanServerAction.invoke(JRMPInvoker.java:805)
            at org.jboss.invocation.jrmp.server.JRMPInvoker.invoke(JRMPInvoker.java:406)
            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:585)
            at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
            at sun.rmi.transport.Transport$1.run(Transport.java:153)
            at java.security.AccessController.doPrivileged(Native Method)
            at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
            at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:460)
            at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:701)
            at java.lang.Thread.run(Thread.java:595)
            Caused by: java.lang.ClassCastException: $Proxy88
            at com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:212)
            ... 42 more


            My interpretation follows:

            Since App2 is loaded in its classloader, when it tries to narrow the home interface of the SB belonging to App1 (which is itself loaded in its own classloader), for the JVM those are two different types (even if it's the same class, this has been loaded by two different class loaders, thus those are two different Java types).

            App2 contained app1-ejb-client.jar as module, but this didn't change a thing.


            Even if I understand what went wrong here, my question is: what is the utility of deployment-based scoping?

            In the company where I work we often have got App1, App2, App3...AppN deployed on Jboss. Most of those apps share some components (let's say a common component). Sometimes, we make changes to the common component and rebuilt, let's say App3. App1, App2, AppN still have got a dependency on the common component which now is different from the common component deployed with App3. So unless we rebuild all the Apps using the common component we risk versions problems; another possible scenario for problems is when the commons component has been loaded by App1 (therefore the unified repository loads the 'old' commons component) and App3 tries to use the new functionalities. Since the loaded commons component is the old one, an error will be thrown because the new functionalities are not in the loaded class.

            So we thought of deployment-based scoping (i.e. adding jboss-app.xml to ear/META-INF). But then we incur in the ClassCastException above.

            What possible solution could be adopted here?





            • 3. Re: problem with JBoss class loading
              Flush Newbie

              I wanted to add a comment to my previous posting: if it's true that deployment-based scoping will cause a ClassCastException in case a component in App2 tries to get through JNDI a component in App1, it is true that in the following scenario, only through deployment-based scoping it will be possible to run the application with success:

              App1: contains a reference to ExternalApp (declared as module in the EAR)
              App2: contains a reference to ExternalApp (declared as module in the EAR)

              However, we added an additional method to ExternalApp and deployed the version with the extra method only with App2.

              If we deploy *without* jboss-app.xml, App1 will load ExternalApp before App2, and since the unified class-loading mechanism follows a first-loaded-first-served strategy, when invoking the additional method on App2, we'll get the following exception:


              2006-02-12 18:55:09,140 ERROR [org.jboss.ejb.plugins.LogInterceptor] Unexpected Error in method: public abstract void uk.co.jemos.uclte
              st2.intf.Session2Session.executeUcl1HelloWorld() throws java.rmi.RemoteException
              java.lang.NoSuchMethodError: uk.co.jemos.ucltestcommon.App.helloWorld2()V
              at uk.co.jemos.ucltest2.ejbs.sessions.Session2Bean.executeUcl1HelloWorld(Session2Bean.java:75)
              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:585)
              at org.jboss.invocation.Invocation.performCall(Invocation.java:345)
              at org.jboss.ejb.StatelessSessionContainer$ContainerInterceptor.invoke(StatelessSessionContainer.java:214)
              at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:149)
              at org.jboss.ejb.plugins.StatelessSessionInstanceInterceptor.invoke(StatelessSessionInstanceInterceptor.java:154)
              at org.jboss.webservice.server.ServiceEndpointInterceptor.invoke(ServiceEndpointInterceptor.java:54)
              at org.jboss.ejb.plugins.CallValidationInterceptor.invoke(CallValidationInterceptor.java:48)
              at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:106)
              at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:335)
              at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:166)
              at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.java:153)
              at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:192)
              at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:122)
              at org.jboss.ejb.SessionContainer.internalInvoke(SessionContainer.java:624)
              at org.jboss.ejb.Container.invoke(Container.java:873)
              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:585)
              at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141)
              at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80)
              at org.jboss.mx.server.Invocation.invoke(Invocation.java:72)
              at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245)
              at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644)
              at org.jboss.invocation.jrmp.server.JRMPInvoker$MBeanServerAction.invoke(JRMPInvoker.java:805)
              at org.jboss.invocation.jrmp.server.JRMPInvoker.invoke(JRMPInvoker.java:406)
              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:585)
              at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
              at sun.rmi.transport.Transport$1.run(Transport.java:153)
              at java.security.AccessController.doPrivileged(Native Method)
              at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
              at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:460)
              at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:701)
              at java.lang.Thread.run(Thread.java:595)


              while if the deploy with deployment-based scoping (i.e. by putting jboss-app.xml in the META-INF folder) the invocation of the new method by App2 will work fine (tested).

              Therefore deployement-based scoping solves the problem of deploying with different version of the same *plain* class, but if our EAR has to use a JNDI component deployed in another EAR, we'll get a ClassCastException, unless there is another way of bypassing the problem.