Hi,

The issue KARAF-4829 was closed. I thought I could now use the config tag as 
long with a location attribute, but I’m wrong!

How to configure a feature in order configuration files to be installed prior 
to bundle startup?

Thanks!

Regards,
JP

De : Guillaume Nodet [mailto:[email protected]]
Envoyé : lundi 3 avril 2017 18:18
À : user
Objet : Re: Blueprint fails instantiating bean with generic constructor



2017-04-03 17:03 GMT+02:00 CLEMENT Jean-Philippe 
<[email protected]<mailto:[email protected]>>:
I understand your point and you’re right, it’s better to test things early than 
let the system crash later on. To go further I guess the Blueprint spec would 
have to be enhanced to fully support generics, for instance to be able to 
instantiate an ArrayList<String> bean, to expose and retrieve services with 
generics signature etc.

That's what I did to some degree with my ARIES-960 branch:
  https://github.com/gnodet/aries/tree/ARIES-960/blueprint/blueprint-core

That's why I'd like some people to look at it and see if their actual use case 
works.
From that point:
  * they work, and that's great
  * they don't work and they should, and I'll work on fixing those
  * they don't work because they require ARIES-1633 which I don't have the time 
to implement in the short term
In the third case, I could look at adding a flag...


That said, a fallback strategy could also be welcome in the meantime. And it 
would be more efficient than letting the system try to convert, fail, then 
finally use the custom “erasure converter” defined in the Blueprint.

Would it be possible to get a nice generics defeat flag?

Please provide a test case for my ARIES-960 branch which falls into the third 
category above.


Regards,
JP

De : Guillaume Nodet [mailto:[email protected]<mailto:[email protected]>]
Envoyé : lundi 3 avril 2017 16:30

À : user
Objet : Re: Blueprint fails instantiating bean with generic constructor

I still am not comfortable allowing casting List<String> to List<Integer> as we 
perfectly know what will happen.
Blueprint is not a compiler, but if you look at CDI, those kind of problems 
have been handled correctly for example, and CDI is not a compiler either, but 
both blueprint and CDI are dependency  injection framework, so there's no 
technical reason to not be able to support the use cases correctly, instead of 
allowing ClassCastException at a later time.

2017-04-03 15:46 GMT+02:00 CLEMENT Jean-Philippe 
<[email protected]<mailto:[email protected]>>:
Hi Guillaume,

As already discussed, Blueprint is not a compiler but a runtime library. Once 
compiled there is no more generics as Java is a type erasure language. 
Moreover, I’m not too sure how Blueprint may handle injection with things like 
<S> S getSomething() where in java you can write myinstance.<Boolean> 
getSomething().

I still do have issues with injection and generics, so a global flag to defeat 
Blueprint checking would be greatly appreciated :)

JP

De : Guillaume Nodet [mailto:[email protected]<mailto:[email protected]>]
Envoyé : lundi 3 avril 2017 14:31
À : user
Objet : Re: Blueprint fails instantiating bean with generic constructor

 There are 2 different issues.
One is type erasure, i.e. allow the invocation of a method taking a 
List<String> with a List<Integer> for example.  That's ARIES-1607, and I really 
think that's a bad idea, unless someone show me a good example where it makes 
sense.  At least by default (well, it's against the blueprint spec anyway).  A 
flag to turn on such a behavior (on a bean or globally) could be an acceptable 
way, though.

Another issue is ARIES-960 where the same thing written in java would work.  
That's a problem of type assignability verification and I'm willing to fix 
those.  I think that's more your use case.  There's a branch I created a while 
ago with some changes.  Could you check if your use case works with the code 
there ?

In all cases, a workaround is always to provide a custom blueprint converter, 
as this would allow converting whatever you want to whatever is needed.



2017-04-03 11:23 GMT+02:00 CLEMENT Jean-Philippe 
<[email protected]<mailto:[email protected]>>:
Hi Setya,

It might be related to an issue I opened last year: 
https://issues.apache.org/jira/browse/ARIES-1607

At that time I was told to add a custom converter as a workaround. No update on 
the Jira since then; maybe you may vote for it :)

Regards,
JP

-----Message d'origine-----
De : Setya [mailto:[email protected]<mailto:[email protected]>]
Envoyé : vendredi 31 mars 2017 19:09
À : [email protected]<mailto:[email protected]>
Objet : Blueprint fails instantiating bean with generic constructor

Hi all,

Aries Blueprint fails to instantiate bean with the following constructors:

public AggregateAnnotationCommandHandler(Class<T> aggregateType, Repository<T> 
repository) { }

It seems to have problems with the second argument since it contains generic 
parameter.

While it successfully instantiates the following bean:

public EventSourcingRepository(AggregateFactory<T> aggregateFactory, EventStore 
eventStore) { }

I'm using Apache Karaf 4.0.8.

Any insight would be greatly appreciated.

Thanks & Regards,
Setya



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