what does this mean?

2003-12-20 14:43:11 StandardContext[/balancer]Exception starting filter BalancerFilter
java.lang.NoClassDefFoundError: org/apache/commons/digester/Digester
 at org.apache.webapp.balancer.RulesParser.createDigester (RulesParser.java:107)
 at org.apache.webapp.balancer.RulesParser.<init>(RulesParser.java:85)
 at org.apache.webapp.balancer.BalancerFilter.init (BalancerFilter.java:121)
 at org.apache.catalina.core.ApplicationFilterConfig.getFilter (ApplicationFilterConfig.java:272)
 at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef (ApplicationFilterConfig.java:355)
 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:126)
 at org.apache.catalina.core.StandardContext.filterStart (StandardContext.java:3646)
 at org.apache.catalina.core.StandardContext.start (StandardContext.java:4263)
 at org.apache.catalina.core.ContainerBase.addChildInternal (ContainerBase.java:866)
 at org.apache.catalina.core.ContainerBase.addChild (ContainerBase.java:850)
 at org.apache.catalina.core.StandardHost.addChild (StandardHost.java:633)
 at org.apache.catalina.core.StandardHostDeployer.install (StandardHostDeployer.java:316)
 at org.apache.catalina.core.StandardHost.install (StandardHost.java:859)
 at org.apache.catalina.startup.HostConfig.deployDirectories (HostConfig.java:723)
 at org.apache.catalina.startup.HostConfig.deployApps (HostConfig.java:473)
 at org.apache.catalina.startup.HostConfig.start (HostConfig.java:1002)
 at org.apache.catalina.startup.HostConfig.lifecycleEvent (HostConfig.java:393)
 at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent (LifecycleSupport.java:166)
 at org.apache.catalina.core.ContainerBase.start (ContainerBase.java:1133)
 at org.apache.catalina.core.StandardHost.start (StandardHost.java:816)
 at org.apache.catalina.core.ContainerBase.start (ContainerBase.java:1125)
 at org.apache.catalina.core.StandardEngine.start (StandardEngine.java:518)
 at org.apache.catalina.core.StandardService.start (StandardService.java:519)
 at org.apache.catalina.core.StandardServer.start (StandardServer.java:2343)
 at org.apache.catalina.startup.Catalina.start (Catalina.java:581)
 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.start (Bootstrap.java:297)
 at org.apache.catalina.startup.Bootstrap.main (Bootstrap.java:398)







 -------Original Message-------
 > From: Leandro Costa <ldcosta@(protected)>
 > Subject: Re: virtual hosting? anyone succeed?
 > Sent: 20 Dec 2003 14:53:14
 >
 > Look at the logs, something is fubar'd, that's why you see a 'blank page'
 >
 >
 >
 > On Sat, 20 Dec 2003 14:34:03 -0400
 >
 > "29djeo" wrote:
 >
 >
 >
 > > Has anyone succeeded in getting tomcat 5.0.16 set up for virtual hosting without using apache as a front end?
 >
 > >
 >
 > > I'm trying to get one instance of tomcat to serve two domains on the same machine.
 >
 > >
 >
 > > I have added two Host sections to server.xml and I see the following behavior when I access the sites from a browser running on the same host as tomcat:
 >
 > >
 >
 > > http://localhost:8080 - default context
 >
 > > http://www.mydomain1.com - blank page
 >
 > > http://www.mydomain2.com - blank page
 >
 > > http://mydomain1:8080 - correctly runs the mydomain1 context
 >
 > > http://mydomain2:8080 - correctly runs the mydomain2 context
 >
 > >
 >
 > > how do I get www.mydomain1.com and www.mydomain2.com to show the correct contexts?
 >
 > >
 >
 > > from another host on my network the only context I can load is http://hostname:8080 to see the default context. All other contexts like http://www.mydomain1.com and http://domain1.com:8080 result in an "action cancelled" from ineternet explorer.
 >
 > >
 >
 > > Here is an excerpt from server.xml:
 >
 > >
 >
 > >  
 >
 > >    
 >
 > >    
 >
 > >    
 >
 > >      
 >
 > >      
 >
 > >      
 >
 > >        
 >
 > >      
 >
 > >      
 >
 > >         www.mydomain1.com
 >
 > >        
 >
 > >        
 >
 > >      
 >
 > >      
 >
 > >         www.mydomain2.com
 >
 > >        
 >
 > >        
 >
 > >      
 >
 > >    
 >
 > >  
 >
 > >
 >
 >
 >
 > ---------------------------------------------------------------------
 >
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 >
 > For additional commands, e-mail: tomcat-user-help@(protected)
 -------Original Message-------