Re: Re: Singleton TopComponents are called twice

> Dear All,
>
> I have not heard anything since filing the singleton TopComponent
> called twice because of @ConvertAsProperties bug report
> (http://www.netbeans.org/issues/show_bug.cgi?id=167395). Just to
> recap, the NetBeans 6.7 TopComponent wizard annotates new singleton
> TopComponents with @ConvertAsProperties. Unfortunately it appears that
> these singleton TopComponent constructors are now called twice: once
> by the getDefault() method as you would expect and then by the no
> argument constructor because @ConvertAsProperties needs to deserialze
> it too. Has anyone else noticed this problem?
>
> I also noticed that since removing the @ConvertAsProperties
> annotations from my TopComponents to prevent this bug my TopComponents
> are no longer displayed when I run my application after building it as
> a ZIP. When I run it from within the NetBeans IDE it all works fine
> though! Any ideas why?
>
> Best wishes,
> Dan
>
> 2009/6/19 Dan Dubois <uvicoxpz@...>:
>> I have done some more investigating and found that the culprit is
>> possibly the @ConvertAsProperties annotation added to the top of each
>> TopComponent. It appears to be deserializing the component after it
>> has already been deserialized the normal way thus calling the
>> singleton TopComponent constructor twice.
>>
>> I can reproduce the problem by cleaning my platform application build.
>> If I run the application the first time, my singleton TopComponents
>> only get their constructors called once which is what I would expect.
>> However, when I close and then rerun the application my singleton
>> TopComponents will each get their constructors called twice.
>>
>> I can remedy this problem by removing the @ConvertAsProperties
>> annotation from my TopComponents, cleaning and rebuilding my
>> application.
>>
>> Is this a bug? I have created
>> http://www.netbeans.org/issues/show_bug.cgi?id=167395 just in case.
>>
>> Best wishes,
>> Dan
>>
>> 2009/6/19 Dan Dubois <uvicoxpz@...>:
>>> Thanks for the input.
>>>
>>> I tried to use the TopComponent wizard for the first time in RC3 to
>>> see if I get the same problems with a fresh TopComponent.
>>> Unfortunately the wizard does not work and produces the following IDE
>>> error after entering my new TopComponent's name and clicking next:
>>>
>>> SEVERE [org.openide.util.RequestProcessor]: Error in RequestProcessor
>>> org.openide.WizardDescriptor$Listener$2$1
>>> java.lang.NoClassDefFoundError: javax/script/ScriptEngineFactory
>>>        at java.lang.ClassLoader.defineClass1(Native Method)
>>>       ...
>>>
>>> I tried deleting the NB home directory ~/.netbeans/6.7rc3 but still
>>> get the error. My application TopComponents were originally created
>>> using the Beta version of NB 6.7.
>>>
>>> Any ideas? Otherwise I suppose I will have to wait for a new NB
>>> release before I can test.
>>>
>>> Best wishes,
>>> Dan
>>>
>>>
>>> 2009/6/19 Tom Wheeler <tomwheel@...>:
>>>> If this is true, it is almost certainly a bug.  I tried, but failed,
>>>> to reproduce this in 6.7 RC3 based on what you said.  It's possible
>>>> that I overlooked some detail of what you did or that there is a bug
>>>> which only affects certain configurations.
>>>>
>>>> As the very definition of Singleton implies, there should only be one
>>>> instance created.  If you've observed this on what is basically an
>>>> unmodified TopComponent as generated by the wizard, then please file a
>>>> bug report on it.
>>>>
>>>> On Fri, Jun 19, 2009 at 12:34 PM, Dan Dubois<uvicoxpz@...> wrote:
>>>>> I should clarify; when I say my singleton TopComponents are being
>>>>> called twice I mean two instances of each TopComponent are being
>>>>> created through their public no argument constructors.
>>>>>
>>>>> 2009/6/19 Dan Dubois <uvicoxpz@...>:
>>>>>> Hi All,
>>>>>>
>>>>>> I have a NetBeans 6.7 RC3 platform application. I registered some
>>>>>> listeners on an object in my TopComponent's constructor and realised
>>>>>> they were being registered twice.
>>>>>>
>>>>>> I discovered this was because all my singleton TopComponents are
>>>>>> called twice during my platform application start up. Once via
>>>>>> reflection, and the second via the getDefault() boilerplate code that
>>>>>> NetBeans generates.
>>>>>>
>>>>>> Is this normal behavior? I can't find anything about it on the web...
>>>>>>
>>>>>> Best wishes,
>>>>>> Dan
>>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Tom Wheeler
>>>> http://www.tomwheeler.com/
>>>>
>>>
>>
>