Tomcat startup problem after adding struts

I just added everything for Thomas Paul's struts example. When I start Tomcat I get the following error:

Sep 18, 2002 12:02:19 PM org.apache.commons.digester.Digester endElement
SEVERE: End event threw exception
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:324)
        at org.apache.commons.beanutils.MethodUtils.invokeMethod(MethodUtils.jav
a:228)
        at org.apache.commons.digester.SetNextRule.end(SetNextRule.java:260)
        at org.apache.commons.digester.Digester.endElement(Digester.java:1036)
        at org.apache.xerces.parsers.AbstractSAXParser.endElement(AbstractSAXPar
ser.java:579)
        at org.apache.xerces.impl.XMLNamespaceBinder.endElement(XMLNamespaceBind
er.java:646)
        at org.apache.xerces.impl.dtd.XMLDTDValidator.handleEndElement(XMLDTDVal
idator.java:1972)
        at org.apache.xerces.impl.dtd.XMLDTDValidator.endElement(XMLDTDValidator
.java:878)
        at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.handleEndElemen
t(XMLDocumentFragmentScannerImpl.java:1144)
        at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanEndElement(
XMLDocumentFragmentScannerImpl.java:987)
        at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContent
Dispatcher.dispatch(XMLDocumentFragmentScannerImpl.java:1445)
        at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(XM
LDocumentFragmentScannerImpl.java:333)
        at org.apache.xerces.parsers.DTDConfiguration.parse(DTDConfiguration.jav
a:524)
        at org.apache.xerces.parsers.DTDConfiguration.parse(DTDConfiguration.jav
a:580)
        at org.apache.xerces.parsers.XMLParser.parse(XMLParser.java:152)
        at org.apache.xerces.parsers.AbstractSAXParser.parse(AbstractSAXParser.j
ava:1169)
        at org.apache.commons.digester.Digester.parse(Digester.java:1514)
        at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDep
loyer.java:335)
        at org.apache.catalina.core.StandardHost.install(StandardHost.java:803)
        at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.j
ava:452)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:409
)
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:879)
        at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java
:368)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(Lifecycl
eSupport.java:166)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1196)
        at org.apache.catalina.core.StandardHost.start(StandardHost.java:738)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1188)
        at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:347
)
        at org.apache.catalina.core.StandardService.start(StandardService.java:4
97)
        at org.apache.catalina.core.StandardServer.start(StandardServer.java:219
1)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:510)
        at org.apache.catalina.startup.Catalina.execute(Catalina.java:400)
        at org.apache.catalina.startup.Catalina.process(Catalina.java:180)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:324)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:203)
Caused by: java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
        at java.lang.ClassLoader.defineClass0(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
3)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:246)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:54)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:193)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:186)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:299)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:265)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:262)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1340)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1274)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:322)
        at java.lang.ClassLoader.defineClass0(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
3)
        at org.apache.catalina.loader.WebappClassLoader.findClassInternal(Webapp
ClassLoader.java:1664)
        at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoa
der.java:953)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1394)
        at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoa
der.java:1274)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.
java:874)
        at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:81
3)
        at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContex
t.java:3342)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:3
534)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase
.java:821)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:80
7)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:579)
        at org.apache.catalina.core.StandardHostDeployer.addChild(StandardHostDe
ployer.java:529)

Tomcat was running fine before that. Does anyone have any ideas on what may be causing this?

Check out the XML Parser(Xerces). Could be that you copied over an older/different version of xerces or crimson. You do go through a mini version of "dll hell" when you are dealing with the xml parsers.
HTH
Ravi

Thanks, Ravi.
I resolved the previous problem by uninstalling Tomcat 4.1 and installing Tomcat 4.0.4. Now I am getting the following error in my log when it tries to load struts:

java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:246)
at java.net.URLClassLoader.access$100(URLClassLoader.java:54)
at java.net.URLClassLoader$1.run(URLClassLoader.java:193)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:186)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:299)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:265)
at java.lang.ClassLoader.loadClass(ClassLoader.java:262)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1320)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1254)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:867)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:810)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3279)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3421)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:785)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:478)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:738)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:300)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:389)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:232)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:155)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1131)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:638)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1123)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:343)
at org.apache.catalina.core.StandardService.start(StandardService.java:388)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:506)
at org.apache.catalina.startup.Catalina.start(Catalina.java:781)
at org.apache.catalina.startup.Catalina.execute(Catalina.java:681)
at org.apache.catalina.startup.Catalina.process(Catalina.java:179)
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.catalina.startup.Bootstrap.main(Bootstrap.java:243)

Other servlets in other web apps are able to load. Any thoughts on this?
[ September 18, 2002: Message edited by: Matthew Phillips ]

How about checking for multiple servlet.jars? There's at least 3 places Tomcat looks for jars.
-In the classpath.
-In the common\lib directory under tomcat
-Under the WEB-INF\lib directory of your web-app
Also there are certain tomcat jar files under \lib directory of the Tomcat installation.
And of course your JDK_HOME directory.
I have had these kind of problems before and I sure wish Java had a decent versioning system for their jars. It does get to be painful to track down the offending jars and libraries.
Regards
Ravi

That's what I was thinking too, but I checked for it. Servlets in other webapps are working. It only occurs with 1 webapp.

It is definately something on this particular PC, because it worked on another PC. I will keep plugging away at it.

The problem was the copy of struts.jar in the jre/lib/ext folder. When I deleted that I was able to get past the startup error.