ClassNotFoundException, how to find where missing class is used

Question

I'm deploying EAR package on Weblogic 12c, and get the ClassNotFoundException. However, seems like the project doesn't have any reference to the missing class in question (I have searched the class name with zero results). I know this exception is thrown when missing class is tried to be instantiated via reflection. I suspect some library may depend on this class.

How do I find out which configuration or user code causes the instantiation of the class? Server log doesn't give enough details, but here it is

<9.8.2017, 1:07:05,113 ip. EEST> <Error> <Console> <BEA-240003> <Administration Console encountered the following error: weblogic.application.ModuleException: java.lang.ClassNotFoundException: fi.foo.bar.service.FoobarWebServiceImpl
    at weblogic.application.internal.ExtensibleModuleWrapper.start(ExtensibleModuleWrapper.java:140)
    at weblogic.application.internal.flow.ModuleListenerInvoker.start(ModuleListenerInvoker.java:124)
    at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:233)
    at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:228)
    at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:45)
    at weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:78)
    at weblogic.application.internal.flow.StartModulesFlow.activate(StartModulesFlow.java:52)
    at weblogic.application.internal.BaseDeployment$2.next(BaseDeployment.java:750)
    at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:45)
    at weblogic.application.internal.BaseDeployment.activate(BaseDeployment.java:260)
    at weblogic.application.internal.EarDeployment.activate(EarDeployment.java:66)
    at weblogic.application.internal.DeploymentStateChecker.activate(DeploymentStateChecker.java:165)
    at weblogic.deploy.internal.targetserver.AppContainerInvoker.activate(AppContainerInvoker.java:90)
    at weblogic.deploy.internal.targetserver.operations.AbstractOperation.activate(AbstractOperation.java:627)
    at weblogic.deploy.internal.targetserver.operations.ActivateOperation.activateDeployment(ActivateOperation.java:171)
    at weblogic.deploy.internal.targetserver.operations.ActivateOperation.doCommit(ActivateOperation.java:121)
    at weblogic.deploy.internal.targetserver.operations.AbstractOperation.commit(AbstractOperation.java:347)
    at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentCommit(DeploymentManager.java:901)
    at weblogic.deploy.internal.targetserver.DeploymentManager.activateDeploymentList(DeploymentManager.java:1456)
    at weblogic.deploy.internal.targetserver.DeploymentManager.handleCommit(DeploymentManager.java:456)
    at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.commit(DeploymentServiceDispatcher.java:181)
    at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doCommitCallback(DeploymentReceiverCallbackDeliverer.java:217)
    at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$100(DeploymentReceiverCallbackDeliverer.java:14)
    at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$2.run(DeploymentReceiverCallbackDeliverer.java:69)
    at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:666)
    at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:348)
    at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:333)
    at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:54)
    at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
    at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:640)
    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:406)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:346)
Caused by: java.lang.ClassNotFoundException: fi.foo.bar.service.FoobarWebServiceImpl
    at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:1026)
    at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:987)
    at weblogic.utils.classloaders.ChangeAwareClassLoader.findClass(ChangeAwareClassLoader.java:83)
    at weblogic.utils.classloaders.GenericClassLoader.doFindClass(GenericClassLoader.java:608)
    at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:540)
    at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:493)
    at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:470)
    at weblogic.utils.classloaders.ChangeAwareClassLoader.loadClass(ChangeAwareClassLoader.java:53)
    at weblogic.servlet.internal.WebAppServletContext.initContainerInitializer(WebAppServletContext.java:1414)
    at weblogic.servlet.internal.WebAppServletContext.initContainerInitializers(WebAppServletContext.java:1360)
    at weblogic.servlet.internal.WebAppServletContext.initContainerInitializers(WebAppServletContext.java:1341)
    at weblogic.servlet.internal.WebAppServletContext.preloadResources(WebAppServletContext.java:1907)
    at weblogic.servlet.internal.WebAppServletContext.start(WebAppServletContext.java:3091)
    at weblogic.servlet.internal.WebAppModule.startContexts(WebAppModule.java:1823)
    at weblogic.servlet.internal.WebAppModule.start(WebAppModule.java:882)
    at weblogic.application.internal.ExtensibleModuleWrapper$StartStateChange.next(ExtensibleModuleWrapper.java:360)
    at weblogic.application.internal.ExtensibleModuleWrapper$StartStateChange.next(ExtensibleModuleWrapper.java:356)
    at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:45)
    at weblogic.application.internal.ExtensibleModuleWrapper.start(ExtensibleModuleWrapper.java:138)

Does it happen in your development environment or only in production mode? Can you debug your application in an IDE? If so, what IDE do you use? — Mehdi Javan, Aug 09 '17 at 11:27
Well, it happens in development environment after I deleted apparently unused class from the library. I have to know where this class is needed, even there is zero reference to it. Maybe the class name is built dynamically somewhere in the framework so I can't search it, but how do I know which class tries to load this class? Why I cant see it from the server log? — Tuomas Toivonen, Aug 09 '17 at 11:47

score 2 · Answer 1 · answered Aug 09 '17 at 12:14

2

Your Weblogic is failing to load Admin Console. Perhaps an eralier deployment of the app with the class in qustion failed. Try the following:

Shutdown all the clusters under that domain
Delete tmp and cache folder on all the servers
Delete config.xml file under pending dirctory
delete the *.lok file on all the servers under /config and /domain folder
re-start Admin
re-start all the managed server
Now deploy the war/ear file and it should work fine…

answered Aug 09 '17 at 12:14

diginoise

7,352
2
31
39

Admin console loads fine (I deploy via admin console). However, I tried this advice and still get same error. – Tuomas Toivonen Aug 09 '17 at 12:31

score 1 · Answer 2 · answered Aug 09 '17 at 12:05

You can use Exception Breakpoint in your IDE to catch ClassNotFoundException. When you add such breakpoint the execution will halt as soon as the exception occurs. Then you can walk through stack, which you can find in your IDE, and by selecting stack lines see the data in each step to find out where your code tries to instantiate an object of that type.

score 0 · Answer 3 · answered Oct 31 '17 at 18:02

0

Your application failed to load 'fi.foo.bar.service.FoobarWebServiceImpl', which is in WebAppServletContext of a WebAppModule. Double check class name for typos for 'fi.foo.bar.service.FoobarWebServiceImpl'in web.xml or weblogic.xml.

answered Oct 31 '17 at 18:02

nick w.

139
3
4

1

That would be nice in comments, not an answer. – Nic3500 Oct 31 '17 at 18:38

ClassNotFoundException, how to find where missing class is used

3 Answers3