Re: [aspectj-users] can we joinpoint on 'java.lang.Object'

[Nicholas Lesiecki <ndlesiecki@xxxxxxxxx>]

Tarun,

Glad I could help. 

> Hmmm... so aspect itself could be advised.? Thats
> good to know.

Yep. This is one of the most common surprises for a new user of  AspectJ.

For more information on these and other common "gotchas" see:

Mastering AspectJ (by yours truly):
http://tinyurl.com/66vf

AspectJ in Action (by Ramnivas Laddad)
http://www.amazon.com/exec/obidos/tg/detail/-/1930110936

The AspectJ FAQ, (which you've probably already read)
http://dev.eclipse.org/viewcvs/indextech.cgi/~checkout~/aspectj-home/doc/faq
.html

Cheers,

Nick
On 8/30/03 4:50 AM, "Tarun Sharma" <t_sharma@xxxxxxxxxxxx> wrote:

> Hi Nick
> 
> Bingo.! right on target. You were absolutely correct and thanks for the
> picking the problem. Hmmm... so aspect itself could be advised.? Thats
> good to know.
> 
> Thanks sooo much Nick for your help.
> 
> Cheers
> Tarun
> 
> 
> On Sat, 30 Aug 2003 01:03:24 -0700, "Nicholas Lesiecki"
> <ndlesiecki@xxxxxxxxx> said:
>> Tarun,
>> 
>> Without further information, I would guess that *.new() is not what you
>> want. Why? Because it will end up advising the constructors of the
>> objects
>> that AspectJ uses to do its work. This creates a problem. The aspect must
>> be
>> constructed to advise any join points, but it cannot be constructed
>> without
>> executing the advice. Try excluding the aspect in question using
>> !within(PostAspect).
>> 
>> Cheers,
>> Nick
>> 
>> On 8/29/03 8:17 PM, "Tarun Sharma" <t_sharma@xxxxxxxxxxxx> wrote:
>> 
>>> Hi Guys
>>> 
>>> Being new to aspectJ, I came across another problem and would highly
>>> appreciate any suggestions or comments on this issue.
>>> 
>>> Basically what I need to do is to put some "pointcut" on any_java_object,
>>> so "java.lang.Object" at "constructor execution" join point.So.. is this
>>> correct "execution(*.new())".?
>>> 
>>> I tried with a very simple aspect WHICH_DOES_NOT_SEEM to work for me. It
>>> was throwing NoClassDefFoundError, obviously I tried to decompile the
>>> class file where it was complaining and checked up the line number (there
>>> was this import org.aspectj.runtime.reflect.Factory ).I also checked the
>>> rt.jar I have in the classpath does indeed have this class file.?? To add
>>> to the mystery, if I dont use pointcut on "java.lang.object" and instead
>>> use on say one of my specialized class then everything is fine and there
>>> are no issue. So, I am not sure how far this error mmessage is correct as
>>> I seem to be stuck with options :
>>> 
>>> Any help will be highly greatful.
>>> 
>>> public aspect PostAspect {
>>> 
>>>   pointcut verify(java.lang.Object o) : execution(*.new()) && this(o);
>>> 
>>>   before(java.lang.Object o) : verify(o) {
>>>    System.out.println("[Aspect] before() : "+thisJoinPoint);
>>>   }
>>> 
>>>   after(java.lang.Object o) : verify(o){
>>>       System.out.println("[Aspect] after() : "+thisJoinPoint);
>>>   }
>>> }
>>> 
>>> Thanks...
>>> Tarun
>> 
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