javax.servlet.ServletException: Error instantiating servlet class
843804Apr 16 2007 — edited Apr 18 2007Hi,
I habe a problem with a Servlet. When I start Tomcat (Version 5.0.28) I get following Exception in the Log-File:
2007-04-16 13:26:41 StandardContext[ukeWebPortal]Marking servlet AbstractQmhPortalServlet as unavailable
2007-04-16 13:26:41 StandardContext[ukeWebPortal]Servlet /ukeWebPortal threw load() exception
javax.servlet.ServletException: Error instantiating servlet class com.ser.uke.servlet.AbstractQmhPortalServlet
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:996)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4357)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:823)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:595)
at org.apache.catalina.core.StandardHostDeployer.addChild(StandardHostDeployer.java:903)
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.beanutils.MethodUtils.invokeMethod(MethodUtils.java:216)
at org.apache.commons.digester.SetNextRule.end(SetNextRule.java:256)
at org.apache.commons.digester.Rule.end(Rule.java:276)
at org.apache.commons.digester.Digester.endElement(Digester.java:1058)
at org.apache.catalina.util.CatalinaDigester.endElement(CatalinaDigester.java:76)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.emptyElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl$ContentDispatcher.scanRootElementHook(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$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.commons.digester.Digester.parse(Digester.java:1567)
at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:488)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:863)
at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:813)
at org.apache.catalina.manager.ManagerServlet.doGet(ManagerServlet.java:320)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)
----- Root Cause -----
java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30)
at java.lang.reflect.Constructor.newInstance(Constructor.java:274)
at java.lang.Class.newInstance0(Class.java:308)
at java.lang.Class.newInstance(Class.java:261)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:987)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4357)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:823)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:595)
at org.apache.catalina.core.StandardHostDeployer.addChild(StandardHostDeployer.java:903)
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.beanutils.MethodUtils.invokeMethod(MethodUtils.java:216)
at org.apache.commons.digester.SetNextRule.end(SetNextRule.java:256)
at org.apache.commons.digester.Rule.end(Rule.java:276)
at org.apache.commons.digester.Digester.endElement(Digester.java:1058)
at org.apache.catalina.util.CatalinaDigester.endElement(CatalinaDigester.java:76)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.emptyElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl$ContentDispatcher.scanRootElementHook(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$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.commons.digester.Digester.parse(Digester.java:1567)
at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:488)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:863)
at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:813)
at org.apache.catalina.manager.ManagerServlet.doGet(ManagerServlet.java:320)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)
This is the relevant part of the web.xml -File:
<web-app>
<servlet>
<servlet-name>AbstractQmhPortalServlet</servlet-name>
<description>Basisklasse fuer die Search-Servlets</description>
<servlet-class>com.ser.uke.servlet.AbstractQmhPortalServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
...
<servlet-mapping>
<servlet-name>AbstractQmhPortalServlet</servlet-name>
<url-pattern>/AbstractQmhPortalServlet</url-pattern>
</servlet-mapping>
...
</web-app>
Wenn I remove the line <load-on-startup>1</load-on-startup> from web.xml the Exception disappears.
I have to load the Servlet on Tomcat startup because the Servlet has to be initialized early.
Why does the Exception appear?
What can I do to fix the Error AND keep the load-on-startup in web.xml?
Please help me. I 'm looking for an answer for a long time.