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Posted to users@wicket.apache.org by salmas <ss...@ecascabel.com> on 2007/11/07 20:05:26 UTC

Why dioes this error occur?

Every once in awhile if I am clicking around for awhile in the UI of my
application I get the following error. What causes this?

java.lang.NullPointerException
	at
wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
	at
wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
	at
wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
	at
wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
	at wicket.RequestCycle.step(RequestCycle.java:992)
	at wicket.RequestCycle.steps(RequestCycle.java:1084)
	at wicket.RequestCycle.request(RequestCycle.java:454)
	at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
	at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
	at
weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
	at
weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
	at
weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
	at
weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
	at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
	at
weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
	at
weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
	at
weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)
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Re: Why dioes this error occur?

Posted by Gwyn Evans <gw...@gmail.com>.
Hi,

  Looking at the code, it's looking like there's some race condition
going on, with the request coming in for a component that no longer
exists.  Comparing with the 1.3 code (in
AbstractRequestCycleProcessor#resolveListenerInterfaceTarget()),
there's an explicit check for a null, but there's nothing that can
really be done to recover, i.e. even the 1.3 code is as follows...

if (component == null)
{
    throw new WicketRuntimeException("component " + pageRelativeComponentPath +
        " not found on page " + page.getClass().getName() + "[id = " +
        page.getNumericId() + "], listener interface = " + listener);
}

Maybe you could disable the button via client-side javascript once
clicked?

/Gwyn

On 07 November 2007, 9:45:24 PM, salmas wrote:
s> I tried disabling the button during the event and while this was easy enough
s> to implement it did not help. My page contains a table which has panels in
s> different cells. I swap these panels in and out depending on wether the user
s> is in 'edit' mode or 'submit' mode and also according to where they are in
s> the workflow. 
s> I noticed that the method of PropertyColumn which I am overriding
s> populateItem(Item item, String componentId, IModel model) completes, as does
s> the event handling code at the button press so I am not sure what is
s> breaking down. It's easy to reproduce this error. All I have to do is to
s> click a button which is present in one of the panels rapidly, at every click
s> I do toggle the name of the button from "edit" to "save" so I don't know if
s> this has something to do with it. 
s> I do need this problem resolved because this is not acceptable for a
s> production application. I would really appreciate any ideas that you have.


s> salmas wrote:
>> 
>> 
>> I am using wicket-1.2.6. Unfortunately it is not possible for me to
>> upgrade to a newer version.
>> 
>>> Hi salmas,
>>>
>>> On 07 November 2007, 7:05:26 PM, salmas wrote:
>>> s> Every once in awhile if I am clicking around for awhile in the UI of
>>> my
>>> s> application I get the following error. What causes this?
>>>
>>> s> java.lang.NullPointerException
>>> s>         at
>>> s>
>>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
>>>
>>> What version of Wicket are you using?
>>>
>>> --
>>> /Gwyn
>>>



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Re: Why dioes this error occur?

Posted by salmas <ss...@ecascabel.com>.
I tried disabling the button during the event and while this was easy enough
to implement it did not help. My page contains a table which has panels in
different cells. I swap these panels in and out depending on wether the user
is in 'edit' mode or 'submit' mode and also according to where they are in
the workflow. 
I noticed that the method of PropertyColumn which I am overriding
populateItem(Item item, String componentId, IModel model) completes, as does
the event handling code at the button press so I am not sure what is
breaking down. It's easy to reproduce this error. All I have to do is to
click a button which is present in one of the panels rapidly, at every click
I do toggle the name of the button from "edit" to "save" so I don't know if
this has something to do with it. 
I do need this problem resolved because this is not acceptable for a
production application. I would really appreciate any ideas that you have.


salmas wrote:
> 
> 
> I am using wicket-1.2.6. Unfortunately it is not possible for me to
> upgrade to a newer version.
> 
>> Hi salmas,
>>
>> On 07 November 2007, 7:05:26 PM, salmas wrote:
>> s> Every once in awhile if I am clicking around for awhile in the UI of
>> my
>> s> application I get the following error. What causes this?
>>
>> s> java.lang.NullPointerException
>> s>         at
>> s>
>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
>>
>> What version of Wicket are you using?
>>
>> --
>> /Gwyn
>>
>>
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>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>>
> 
> 
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> 
> 
> 

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Re: Why dioes this error occur?

Posted by ss...@ecascabel.com.
I am using wicket-1.2.6. Unfortunately it is not possible for me to
upgrade to a newer version.

> Hi salmas,
>
> On 07 November 2007, 7:05:26 PM, salmas wrote:
> s> Every once in awhile if I am clicking around for awhile in the UI of my
> s> application I get the following error. What causes this?
>
> s> java.lang.NullPointerException
> s>         at
> s>
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
>
> What version of Wicket are you using?
>
> --
> /Gwyn
>
>
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> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>


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Re: Why dioes this error occur?

Posted by Gwyn Evans <gw...@gmail.com>.
Hi salmas,

On 07 November 2007, 7:05:26 PM, salmas wrote:
s> Every once in awhile if I am clicking around for awhile in the UI of my
s> application I get the following error. What causes this?

s> java.lang.NullPointerException
s>         at
s> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)

What version of Wicket are you using?

-- 
/Gwyn


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Re: Why dioes this error occur?

Posted by Timo Rantalaiho <Ti...@ri.fi>.
On Fri, 04 Jan 2008, wicket21 wrote:
> a) reading the Ajax -> Links Example  (get the starting point: use
> AjaxCallDecorator)
> b) finding/writing a js function to display a layer to cover all the visible
> area of the window + disallow any user clicks (similar behaviour as the
> layer behind the modal window)
> c) calling this js function before the ajax call
> d) calling some more js code to hide the extra layer after the ajax call

Making your Ajax-Behavior implement IAjaxIndicatorAware you
can automatise the major part of this.

Best wishes,
Timo


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Re: Why dioes this error occur?

Posted by wicket21 <ko...@yahoo.com>.
We solved more or less the same problem by 

a) reading the Ajax -> Links Example  (get the starting point: use
AjaxCallDecorator)
b) finding/writing a js function to display a layer to cover all the visible
area of the window + disallow any user clicks (similar behaviour as the
layer behind the modal window)
c) calling this js function before the ajax call
d) calling some more js code to hide the extra layer after the ajax call

Step d is not needed when u r using setResponsePage.

I think using target.append/prependJavascript might do the job as well.

Regards,
Konstantinos



salmas wrote:
> 
> 
> It seems that this is a common bug, there is a thread titled
> "Doubleclicking on a refreshable Ajax button" which appears to be similar.
> I am using an AjaxSubmitButton in my application and double clicks and
> fast clicks are an issue. 
> I have followed the sugggestions to use javascript to disable the button
> between clicks and while this reduced the frequency it still does occur
> from time to time. We cannot move to my application to prodution like this
> and my manager does not want this application to have to go to a newer
> wicket since we'll have to start from scratch with testing. Would it be
> possible to release a patch for older releases such as wicket-1.2.6? This
> would be huge for my project.
> 
> Regards
> 
> 
> serban.balamaci wrote:
>> 
>> Hi. Well in my case this error apeared when the user clicked on a link
>> that was directing the user to the next page, and while the user did not
>> wait for the other page to load, or he thought that he did not press the
>> mouse button and he clicked again. The server saw that the
>> component(link) was no longer in the the new page and therefore the
>> nullpointer. (Or that's how i explained it to myself). I got around this
>> by disabling the link after the clicking.
>> 
>> 
>> 
>> salmas wrote:
>>> 
>>> Every once in awhile if I am clicking around for awhile in the UI of my
>>> application I get the following error. What causes this?
>>> 
>>> java.lang.NullPointerException
>>> 	at
>>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
>>> 	at
>>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
>>> 	at
>>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
>>> 	at
>>> wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
>>> 	at wicket.RequestCycle.step(RequestCycle.java:992)
>>> 	at wicket.RequestCycle.steps(RequestCycle.java:1084)
>>> 	at wicket.RequestCycle.request(RequestCycle.java:454)
>>> 	at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
>>> 	at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
>>> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
>>> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
>>> 	at
>>> weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
>>> 	at
>>> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
>>> 	at
>>> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
>>> 	at
>>> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
>>> 	at
>>> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
>>> 	at
>>> weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
>>> 	at
>>> weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
>>> 	at
>>> weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
>>> 	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
>>> 	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)
>>> 
>> 
>> 
> 
> 

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Re: Why dioes this error occur?

Posted by Charlie Dobbie <cf...@gmail.com>.
Hi all,

I am encountering the same issue as the OP reports, but it is not
related to double-clicking.  My situation is as follows:  (Using
Wicket 1.2.6, Databinder 1.0)


I have a PropertyListView using a HibernateListModel that selects a
number of objects from the database.  One of the components rendered
per item is an AjaxLink that opens a ModalWindow.  Inside the
ModalWindow is an AjaxLink whose onClick updates the object (such that
it will no longer appear in the list), detaches the model backing the
list and adds the PropertyListView to the AjaxRequestTarget.  The
screen refreshes, and the object is no longer listed.

It *works*, in that when the correct link is clicked, the ModalWindow
closes, the database is updated, and the page refreshes without the
object that was just actioned.  However, I'm getting the OP's
exception trace in the logs.  I presume what's happening is that
something is performing some kind of finishing-up callback to the
ModalWindow or one of the AjaxLinks, which then fails because the
component is no longer on the page.


I'm afraid I don't have a great grasp of the process around the
ModalWindow - have I diagnosed the problem correctly?  Given that my
code works (so whatever is broken isn't vital), and given that the
stack trace for the exception doesn't go near my code (so I can't just
intercept and ignore the Exception), what can I do to fix it?  Is
there a better approach to my problem that avoids this issue?

Cheers,
Charlie.



On Nov 21, 2007 6:05 PM, salmas <ss...@ecascabel.com> wrote:
>
> It seems that this is a common bug, there is a thread titled "Doubleclicking
> on a refreshable Ajax button" which appears to be similar. I am using an
> AjaxSubmitButton in my application and double clicks and fast clicks are an
> issue.
> I have followed the sugggestions to use javascript to disable the button
> between clicks and while this reduced the frequency it still does occur from
> time to time. We cannot move to my application to prodution like this and my
> manager does not want this application to have to go to a newer wicket since
> we'll have to start from scratch with testing. Would it be possible to
> release a patch for older releases such as wicket-1.2.6? This would be huge
> for my project.
>
> Regards
>
>
> serban.balamaci wrote:
> >
> > Hi. Well in my case this error apeared when the user clicked on a link
> > that was directing the user to the next page, and while the user did not
> > wait for the other page to load, or he thought that he did not press the
> > mouse button and he clicked again. The server saw that the component(link)
> > was no longer in the the new page and therefore the nullpointer. (Or
> > that's how i explained it to myself). I got around this by disabling the
> > link after the clicking.
> >
> >
> >
> > salmas wrote:
> >>
> >> Every once in awhile if I am clicking around for awhile in the UI of my
> >> application I get the following error. What causes this?
> >>
> >> java.lang.NullPointerException
> >>      at
> >> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
> >>      at
> >> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
> >>      at
> >> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
> >>      at
> >> wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
> >>      at wicket.RequestCycle.step(RequestCycle.java:992)
> >>      at wicket.RequestCycle.steps(RequestCycle.java:1084)
> >>      at wicket.RequestCycle.request(RequestCycle.java:454)
> >>      at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
> >>      at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
> >>      at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
> >>      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
> >>      at
> >> weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
> >>      at
> >> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
> >>      at
> >> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
> >>      at
> >> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
> >>      at
> >> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
> >>      at
> >> weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
> >>      at
> >> weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
> >>      at
> >> weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
> >>      at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
> >>      at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)

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Re: Why dioes this error occur?

Posted by salmas <ss...@ecascabel.com>.

It seems that this is a common bug, there is a thread titled "Doubleclicking
on a refreshable Ajax button" which appears to be similar. I am using an
AjaxSubmitButton in my application and double clicks and fast clicks are an
issue. 
I have followed the sugggestions to use javascript to disable the button
between clicks and while this reduced the frequency it still does occur from
time to time. We cannot move to my application to prodution like this and my
manager does not want this application to have to go to a newer wicket since
we'll have to start from scratch with testing. Would it be possible to
release a patch for older releases such as wicket-1.2.6? This would be huge
for my project.

Regards


serban.balamaci wrote:
> 
> Hi. Well in my case this error apeared when the user clicked on a link
> that was directing the user to the next page, and while the user did not
> wait for the other page to load, or he thought that he did not press the
> mouse button and he clicked again. The server saw that the component(link)
> was no longer in the the new page and therefore the nullpointer. (Or
> that's how i explained it to myself). I got around this by disabling the
> link after the clicking.
> 
> 
> 
> salmas wrote:
>> 
>> Every once in awhile if I am clicking around for awhile in the UI of my
>> application I get the following error. What causes this?
>> 
>> java.lang.NullPointerException
>> 	at
>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
>> 	at
>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
>> 	at
>> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
>> 	at
>> wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
>> 	at wicket.RequestCycle.step(RequestCycle.java:992)
>> 	at wicket.RequestCycle.steps(RequestCycle.java:1084)
>> 	at wicket.RequestCycle.request(RequestCycle.java:454)
>> 	at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
>> 	at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
>> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
>> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
>> 	at
>> weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
>> 	at
>> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
>> 	at
>> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
>> 	at
>> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
>> 	at
>> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
>> 	at
>> weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
>> 	at
>> weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
>> 	at
>> weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
>> 	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
>> 	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)
>> 
> 
> 

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Re: Why dioes this error occur?

Posted by "serban.balamaci" <ta...@yahoo.com>.
Hi. Well in my case this error apeared when the user clicked on a link that
was directing the user to the next page, and while the user did not wait for
the other page to load, or he thought that he did not press the mouse button
and he clicked again. The server saw that the component(link) was no longer
in the the new page and therefore the nullpointer. I got around this by
disabling the link after the clicking.



salmas wrote:
> 
> Every once in awhile if I am clicking around for awhile in the UI of my
> application I get the following error. What causes this?
> 
> java.lang.NullPointerException
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
> 	at
> wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
> 	at wicket.RequestCycle.step(RequestCycle.java:992)
> 	at wicket.RequestCycle.steps(RequestCycle.java:1084)
> 	at wicket.RequestCycle.request(RequestCycle.java:454)
> 	at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
> 	at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
> 	at
> weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
> 	at
> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
> 	at
> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
> 	at
> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
> 	at
> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
> 	at
> weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
> 	at
> weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
> 	at
> weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
> 	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
> 	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)
> 

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Re: Why dioes this error occur?

Posted by "serban.balamaci" <ta...@yahoo.com>.
Hi. Well in my case this error apeared when the user clicked on a link that
was directing the user to the next page, and while the user did not wait for
the other page to load, or he thought that he did not press the mouse button
and he clicked again. The server saw that the component(link) was no longer
in the the new page and therefore the nullpointer. (Or that's how i
explained it to myself). I got around this by disabling the link after the
clicking.



salmas wrote:
> 
> Every once in awhile if I am clicking around for awhile in the UI of my
> application I get the following error. What causes this?
> 
> java.lang.NullPointerException
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveListenerInterfaceTarget(DefaultRequestTargetResolverStrategy.java:295)
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolveRenderedPage(DefaultRequestTargetResolverStrategy.java:228)
> 	at
> wicket.request.compound.DefaultRequestTargetResolverStrategy.resolve(DefaultRequestTargetResolverStrategy.java:153)
> 	at
> wicket.request.compound.AbstractCompoundRequestCycleProcessor.resolve(AbstractCompoundRequestCycleProcessor.java:48)
> 	at wicket.RequestCycle.step(RequestCycle.java:992)
> 	at wicket.RequestCycle.steps(RequestCycle.java:1084)
> 	at wicket.RequestCycle.request(RequestCycle.java:454)
> 	at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:219)
> 	at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:262)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
> 	at
> weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1072)
> 	at
> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
> 	at
> weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
> 	at
> weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6981)
> 	at
> weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
> 	at
> weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
> 	at
> weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3892)
> 	at
> weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2766)
> 	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
> 	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)
> 

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