Servlet: "XYZ" failed to preload on startup in Web application

Question

Hi,
When i deploying the WAR(serviceregistry.war) in weblogic 9.2,i am getting following errors,
[HTTP:101216]Servlet: "BasicServlet" failed to preload on startup in Web application:
"serviceregistry.war". java.lang.NullPointerException at java.util.Hashtable.put(Hashtable.java:396) at
java.util.Properties.setProperty(Properties.java:128) at java.lang.System.setProperty(System.java:700) at
com.ssc.faw.controller.BasicServlet.init(BasicServlet.java:30) at
weblogic.servlet.internal.StubSecurityHelper$ServletInitAction.run(StubSecurityHelper.java:276) at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321) at
weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121) at
weblogic.servlet.internal.StubSecurityHelper.createServlet(StubSecurityHelper.java:68) at
weblogic.servlet.internal.StubLifecycleHelper.createOneInstance(StubLifecycleHelper.java:58) at
weblogic.servlet.internal.StubLifecycleHelper.<init>(StubLifecycleHelper.java:48) at
weblogic.servlet.internal.ServletStubImpl.prepareServlet(ServletStubImpl.java:504) at
weblogic.servlet.internal.WebAppServletContext.preloadServlet(WebAppServletContext.java:1698) at
weblogic.servlet.internal.WebAppServletContext.loadServletsOnStartup(WebAppServletContext.java:1675) at
weblogic.servlet.internal.WebAppServletContext.preloadResources(WebAppServletContext.java:1595) at
weblogic.servlet.internal.WebAppServletContext.start(WebAppServletContext.java:2734) at
weblogic.servlet.internal.WebAppModule.startContexts(WebAppModule.java:892) at
weblogic.servlet.internal.WebAppModule.start(WebAppModule.java:336) at
weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:204) at
weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:26) at
weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:60) at
weblogic.application.internal.flow.ScopedModuleDriver.start(ScopedModuleDriver.java:200) at
weblogic.application.internal.flow.ModuleListenerInvoker.start(ModuleListenerInvoker.java:117) at
weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:204) at
weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:26) at
weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:60) at
weblogic.application.internal.flow.StartModulesFlow.activate(StartModulesFlow.java:26) at
weblogic.application.internal.BaseDeployment$2.next(BaseDeployment.java:641) at
weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:26) at
weblogic.application.internal.BaseDeployment.activate(BaseDeployment.java:229) at
weblogic.application.internal.DeploymentStateChecker.activate(DeploymentStateChecker.java:154) at
weblogic.deploy.internal.targetserver.AppContainerInvoker.activate(AppContainerInvoker.java:80) at
weblogic.deploy.internal.targetserver.operations.AbstractOperation.activate(AbstractOperation.java:565) at
weblogic.deploy.internal.targetserver.operations.ActivateOperation.activateDeployment(ActivateOperation.java:136)
at weblogic.deploy.internal.targetserver.operations.ActivateOperation.doCommit(ActivateOperation.java:104) at
weblogic.deploy.internal.targetserver.operations.StartOperation.doCommit(StartOperation.java:128) at
weblogic.deploy.internal.targetserver.operations.AbstractOperation.commit(AbstractOperation.java:320) at
weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentCommit(DeploymentManager.java:815) at
weblogic.deploy.internal.targetserver.DeploymentManager.activateDeploymentList(DeploymentManager.java:1222) at
weblogic.deploy.internal.targetserver.DeploymentManager.handleCommit(DeploymentManager.java:433) at
weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.commit(DeploymentServiceDispatcher.java:161) at
weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doCommitCallback
(DeploymentReceiverCallbackDeliverer.java:181) at
weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$100
(DeploymentReceiverCallbackDeliverer.java:12) at
weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$2.run
(DeploymentReceiverCallbackDeliverer.java:67) at weblogic.work.ServerWorkManagerImpl$WorkAdapterImpl.run
(ServerWorkManagerImpl.java:518) at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209) at
weblogic.work.ExecuteThread.run(ExecuteThread.java:181)      
Please give me some solutions
Regards,
Tamilvanan.G

Answer 1

Hi 835570,
As per Rene, the failed init process is due to the NulllPointerException. A NullPointerException is to be expected when JDK HashTable data structure is receiving a null object value for the put() operation.
Recommendations #1
- Look and review your application code >> com.ssc.faw.controller.BasicServlet.init(BasicServlet.java:30).
I can see that you are trying to initialize a java.util.Properties but you are passing a null value to the Properties Object at line 30 of your Servlet. You need to understand why.
Solution:
- Understand why you are attemtping to pass a null value to your Properties object and fix the problem
- Add try{}catch{} block along with proper logging within your custom Servlet code to gracefully handle and log any Unexpected NulllPointerException and prevent such Exception to completely abort your Servlet loading process.
Regards
P-H
http://javaeesupportpatterns.blogspot.com/
Edited by: PHCharbonneau on 12-Feb-2011 5:39 AM
Edited by: PHCharbonneau on 12-Feb-2011 5:39 AM