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Re: Anybody know what is this situation?
by jthomerson
::
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Generally unexplained class issues like this are because the same
class gets loaded a second time from a different class loader. I once
had it throwing a ClassCastException that ClassA != ClassA. Hard to
track down, though.
--
Jeremy Thomerson
http://www.wickettraining.com
On Fri, Jul 3, 2009 at 4:27 PM, bgooren<bas@...> wrote:
>
> I got the same error today, seems totally random.
>
> The only possible explanation I have is that maybe the subclass (LoginPage$1
> in your case) stores a PageHolder class instead of the actual page
> (LoginPage) when serialized, and when LoginPage$1 is deserialized, the
> PageHolder retrieves/points to a different Page.
>
> I was just as baffled as you since in my case the two classes were totally
> different, like in your case (com.application.MainPage vs
> wicket.quickstart.LoginPage).
> In my case it's two pages from the same application, but they are
> functionally separate and never interact.
>
> In my case I made the inner class that caused the problem a static inner
> class. Since I have been unable to reproduce the problem I cannot confirm if
> this resolves the problem.
>
> Can you share what kind of class LoginPage$1 is? (it's the first anonymous
> inner class in LoginPage) Is it a class which extends IModel?
>
> Also, you someone from the Wicket team confirm if my explanation above is
> possible at all (PageHolder retrieving a different class when
> deserializing)?
>
> Bas
>
>
> MartinM wrote:
>>
>> Anybody know what is this situation? Wicket 1.4-rc4
>>
>> From production:
>>
>> 2009-05-18 16:32:44,316 19598423 [btpool0-112] ERROR RequestCycle -
>> cannot assign instance of com.application.MainPage to field
>> wicket.quickstart.LoginPage$1.this$0 of type
>> wicket.quickstart.LoginPage in instance of
>> wicket.quickstart.LoginPage$1
>> java.lang.ClassCastException: cannot assign instance of
>> com.application.MainPage to field wicket.quickstart.LoginPage$1.this$0
>> of type wicket.quickstart.LoginPage in instance of
>> wicket.quickstart.LoginPage$1
>> at
>> java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2032)
>> at
>> java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:1212)
>>
>> .. etc ...
>>
>
> --
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>
>
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class gets loaded a second time from a different class loader. I once
had it throwing a ClassCastException that ClassA != ClassA. Hard to
track down, though.
--
Jeremy Thomerson
http://www.wickettraining.com
On Fri, Jul 3, 2009 at 4:27 PM, bgooren<bas@...> wrote:
>
> I got the same error today, seems totally random.
>
> The only possible explanation I have is that maybe the subclass (LoginPage$1
> in your case) stores a PageHolder class instead of the actual page
> (LoginPage) when serialized, and when LoginPage$1 is deserialized, the
> PageHolder retrieves/points to a different Page.
>
> I was just as baffled as you since in my case the two classes were totally
> different, like in your case (com.application.MainPage vs
> wicket.quickstart.LoginPage).
> In my case it's two pages from the same application, but they are
> functionally separate and never interact.
>
> In my case I made the inner class that caused the problem a static inner
> class. Since I have been unable to reproduce the problem I cannot confirm if
> this resolves the problem.
>
> Can you share what kind of class LoginPage$1 is? (it's the first anonymous
> inner class in LoginPage) Is it a class which extends IModel?
>
> Also, you someone from the Wicket team confirm if my explanation above is
> possible at all (PageHolder retrieving a different class when
> deserializing)?
>
> Bas
>
>
> MartinM wrote:
>>
>> Anybody know what is this situation? Wicket 1.4-rc4
>>
>> From production:
>>
>> 2009-05-18 16:32:44,316 19598423 [btpool0-112] ERROR RequestCycle -
>> cannot assign instance of com.application.MainPage to field
>> wicket.quickstart.LoginPage$1.this$0 of type
>> wicket.quickstart.LoginPage in instance of
>> wicket.quickstart.LoginPage$1
>> java.lang.ClassCastException: cannot assign instance of
>> com.application.MainPage to field wicket.quickstart.LoginPage$1.this$0
>> of type wicket.quickstart.LoginPage in instance of
>> wicket.quickstart.LoginPage$1
>> at
>> java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2032)
>> at
>> java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:1212)
>>
>> .. etc ...
>>
>
> --
> View this message in context: http://www.nabble.com/Anybody-know-what-is-this-situation--tp23597800p24329006.html
> Sent from the Wicket - User mailing list archive at Nabble.com.
>
>
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> To unsubscribe, e-mail: users-unsubscribe@...
> For additional commands, e-mail: users-help@...
>
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