I have just run into the ConcurrentModificationException on my dev server. Not
that I can reproduce it, but I got more details:
1. my session has expired
2. the PageExpiredErrorPage SessionErr was invoked. Internally it executed
this statement:
public SessionErr ()
{
super ();
log.info ("Before replaceAllRequestHandlers");
getRequestCycle().replaceAllRequestHandlers (new SessionErrHandler());
}
3. SessionErrHandler was created,
public SessionErrHandler()
{
super(LOG_BACKIN_URL);
log.info ("RedirectRequest");
}
Log:
INFO 06 15:23:58.755 Before replaceAllRequestHandlers [m.p.SessionErr]
INFO 06 15:23:58.755 RedirectRequest [m.SessionErrHandler]
INFO 06 15:23:58.760 Before replaceAllRequestHandlers [m.p.SessionErr]
INFO 06 15:23:58.760 RedirectRequest [m.SessionErrHandler]
On the browser, HTTP Status 500 -
java.util.ConcurrentModificationException
java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
java.util.AbstractList$Itr.next(AbstractList.java:343)
org.apache.wicket.request.RequestHandlerStack.detach(RequestHandlerStack.java:176)
org.apache.wicket.request.cycle.RequestCycle.onDetach(RequestCycle.java:565)
org.apache.wicket.request.cycle.RequestCycle.detach(RequestCycle.java:508)
org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:284)
org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:162)
org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:218)
-----Original Message-----
From: Fang Lin [mailto:fang...@u.washington.edu]
Sent: Tuesday, December 06, 2011 2:06 PM
To: users@wicket.apache.org
Subject: RE: ConcurrentModificationException
I have been trying to reproduce it on our dev server this morning, but could
not. However I did run into it twice on our production server yesterday.
I wonder if you could answer my question "Is this exception handler invoked
before or after the ErrorPages ?"
-----Original Message-----
From: Martin Grigorov [mailto:mgrigo...@apache.org]
Sent: Tuesday, December 06, 2011 12:47 PM
To: users@wicket.apache.org
Subject: Re: ConcurrentModificationException
No, I don't see anything wrong here.
If you are able to reproduce it then we can debug it.
On Tue, Dec 6, 2011 at 9:40 PM, Fang Lin <fang...@u.washington.edu> wrote:
> Thanks, Martin!
>
> In the init(), I have:
> {
> getMarkupSettings().setStripWicketTags(true);
>
> IApplicationSettings settings = getApplicationSettings();
> settings.setAccessDeniedPage(AccessErr.class);
> settings.setPageExpiredErrorPage(SessionErr.class);
> settings.setInternalErrorPage(InternalErr.class);
>
> // #2 starts
> getRequestCycleListeners().add(new AbstractRequestCycleListener() {
>
> public IRequestHandler onException(RequestCycle cycle, Exception e)
> {
> return new RedirectRequestHandler (ERROR_PAGE_URL);
> }
> });
> // #2 ends
> }
> Could the #2 code block be the cause? Is this exception handler invoked
> before or after the ErrorPages ?
>
> Our authentication strategy is set up at Apache level.
> This is what SessionErr class does:
> getRequestCycle().replaceAllRequestHandlers (new SessionErrHandler());
>
> And SessionErrHandler redirect to the Login Servlet. And the Login Servlet
> will be routed to the WebLogin server.
>
> -----Original Message-----
> From: Martin Grigorov [mailto:mgrigo...@apache.org]
> Sent: Monday, December 05, 2011 11:59 PM
> To: users@wicket.apache.org
> Subject: Re: ConcurrentModificationException
>
> Hi,
>
> I don't see how this may happen.
> The execution of RequestCycle is single threaded.
> Do you have RequestCycleListener or something similar where you start another
> thread and you use the same instance of RequestCycle ?
>
> On Tue, Dec 6, 2011 at 2:31 AM, Fang Lin <fang...@u.washington.edu> wrote:
>> When clicking on a link (i.e., ?5-1.ILinkListener-...) after a session
>> expired, this error page shows up on my browser window:
>> Exception report
>> message
>> description The server encountered an internal error () that prevented it
>> from fulfilling this request.
>> exception
>> java.util.ConcurrentModificationException
>>
>> java.util.AbstractList$Itr.checkForComodification(AbstractList.java:37
>> 2)
>>
>> java.util.AbstractList$Itr.next(AbstractList.java:343)
>>
>> org.apache.wicket.request.RequestHandlerStack.detach(RequestHandlerSta
>> ck.java:176)
>>
>> org.apache.wicket.request.cycle.RequestCycle.onDetach(RequestCycle.jav
>> a:565)
>>
>> org.apache.wicket.request.cycle.RequestCycle.detach(RequestCycle.java:
>> 508)
>>
>> org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(R
>> equestCycle.java:284)
>>
>> org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilt
>> er.java:162)
>>
>> org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.jav
>> a:218)
>> at
>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
>> cationFilterChain.java:235)
>> at
>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
>> lterChain.java:206)
>> at
>> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
>> lve.java:233)
>> at
>> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
>> lve.java:191)
>> at
>> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
>> va:127)
>> at
>> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
>> va:102)
>> at
>> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
>> e.java:109)
>> at
>> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java
>> :298)
>> at
>> org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
>> at
>> org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
>> at
>> org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:774)
>> at
>> org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.jav
>> a:703)
>> at
>> org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocke
>> t.java:896)
>> at
>> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
>> ol.java:690)
>> at java.lang.Thread.run(Thread.java:662)
>> This ConcurrentModificationException occurs about 70+ times on an
>> application server daily.
>> Wicket version 1.5.3.
>> Any suggestion on how to avoid this?
>> In the init method of sub-class of the WebApplication , I have:
>> IApplicationSettings settings = getApplicationSettings();
>> settings.setAccessDeniedPage(AccessErr.class);
>> settings.setPageExpiredErrorPage(SessionErr.class);
>> settings.setInternalErrorPage(InternalErr.class);
>> When a session expired, should it invoke the PageExpiredErrorPage?
>
> Yes. You make a request to a page, Wicket searches for this page in the
> stores, doesn't find it and throws PageExpiredException.
> But, if the request url has the mount path then Wicket will create a new Page
> instance instead. If you have authentication strategy set up then you go to
> the Login page, otherwise this page will be rendered.
>
> If you are able to reproduce the problem in a quickstart attach it to Jira so
> we can debug it.
> Thanks!
>
>> -Fang
>>
>>
>
>
>
> --
> Martin Grigorov
> jWeekend
> Training, Consulting, Development
> http://jWeekend.com
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
> For additional commands, e-mail: users-h...@wicket.apache.org
>
--
Martin Grigorov
jWeekend
Training, Consulting, Development
http://jWeekend.com
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
