users@javaee-spec.java.net

[javaee-spec users] [jsr342-experts] Re: CDI positioning

From: Werner Keil <werner.keil_at_gmail.com>
Date: Fri, 31 Aug 2012 17:30:55 +0200

Good points. Where those are part of existing active JSRs, there should be
coordination and guidance. I remember, EC Members including myself and some
from the EE6 EG like Mike Keith mediated between @Inject and CDI in the
first place.
Chances are, we can find a few more such cross-EG experts here this time?;-)

I am also both in JSF and CDI, so that could help in those cases. JAX-RS I
so far mainly use as consumer in projects like Agorava. Where we also try
to leverage CDI the best way possible. As the Spec Lead I believe is
Oracle, too, there should be ways to reach them.

Werner
Am 31.08.2012 17:22 schrieb "Antonio Goncalves" <antonio.goncalves_at_gmail.com
>:

> Well, that would be awesome, but is there anybody here who is part of
> JAX-RS Expert Group and could tell us if it's doable or not ?
>
> Same, do we know what the JSF 2.2 EG plans to do with @ManagedBean vs
> @Named ?
>
> On Fri, Aug 31, 2012 at 5:10 PM, Pete Muir <pmuir_at_bleepbleep.org.uk>wrote:
>
>> Well, I think based on D, injection is something that CDI provides, and
>> JAX-RS is fully functional without injection, so JAX-RS shouldn't provide
>> @Context at all as it duplicates functionality from CDI.
>>
>> On 31 Aug 2012, at 16:06, Antonio Goncalves wrote:
>>
>> > Pete, what would that mean for the following example ? This is the way
>> you inject UriInfo with JAX-RS :
>> >
>> >
>> > @Path(
>> > "/resource"
>> > )
>> >
>> > public
>> > class Resource {
>> >
>> > @Context
>> >
>> >
>> > private UriInfo info;
>> >
>> >
>> >
>> >
>> > Injection is made with @Context in a standalone mode without CDI. But
>> in a Java EE container I would really like to use @Inject rather than
>> @Context (so the code is not portable anymore without CDI) :
>> >
>> >
>> > @Path(
>> > "/resource"
>> > )
>> >
>> > public
>> > class Resource {
>> >
>> > @Inject
>> >
>> >
>> > private UriInfo info;
>> >
>> >
>> > Antonio
>> > On Fri, Aug 31, 2012 at 4:55 PM, Pete Muir <pmuir_at_bleepbleep.org.uk>
>> wrote:
>> > Bill, et al
>> >
>> > We would like to propose a slight variant on option C:
>> >
>> > D. Technologies that can be standalone specifications (JMS, JAX-RS)
>> should be fully functional without CDI, but they should not duplicate any
>> features of CDI. When CDI is present, these technologies should leverage
>> and integrate with CDI where appropriate.
>> >
>> > On 30 Aug 2012, at 21:58, Bill Shannon wrote:
>> >
>> > > From many of our recent discussions, it seems clear that CDI is
>> > > becoming more central to the Java EE programming model. For example:
>> > >
>> > > - The expanded use of @Stereotype in my previous message.
>> > >
>> > > - The use of CDI interceptors to provide container managed
>> > > transaction support beyond EJB.
>> > >
>> > > - The potential future use of CDI interceptors to provide container
>> > > managed security support beyond EJB.
>> > >
>> > > - The use of CDI interceptors to support Bean Validation method
>> > > level validation.
>> > >
>> > > - The discussion of "implicit producers" to allow use of @Inject
>> > > instead of @Resource to inject Java EE resources.
>> > >
>> > > - The discussion around alignment of CDI managed beans and the
>> > > separate @ManagedBean spec.
>> > >
>> > > - The introduction of a transaction scope and its use in the JMS
>> > > spec to simplify the programming model.
>> > >
>> > > - The change being considered by the CDI expert group to enable
>> > > CDI by default, making it more attractive to use it for all
>> > > the items above.
>> > >
>> > >
>> > > At the same time we're finding that some specs, e.g., JAX-RS, are
>> > > hesitant to introduce a hard, or even soft, dependency on CDI,
>> > > instead insisting that all their new features must work in an
>> > > environment where there is no CDI.
>> > >
>> > > In many ways this parallels what we saw with annotations. In
>> > > the beginning we found many people who didn't want to use annotations
>> > > and wanted us to make sure everything worked without use of
>> > > annotations. Now we're seeing many things that *only* work with
>> > > annotations, and annotations are well accepted by Java EE developers.
>> > > I suppose there's a natural lifecycle to acceptance of new
>> > > technologies, and I wonder where we are in that lifecycle with CDI?
>> > > Has CDI become a mature and accepted technology that we should use
>> > > widely?
>> > >
>> > >
>> > > I'd like to get a sense from this group as to what direction we
>> > > should provide to all the Java EE specs in regards to their use
>> > > of CDI. Here's a few obvious options:
>> > >
>> > > A. Technologies that see a significant standalone (non-Java EE) use
>> > > should be fully functional without CDI. If necessary, any
>> > > required features that are similar to CDI features should be
>> > > defined and implemented in a way that doesn't depend on CDI.
>> > >
>> > > B. Technologies should provide all major features in a way that
>> > > works without CDI. Some features may also be provided in a
>> > > different way that works well with CDI. Some less essential
>> > > features may only work with CDI. The implementation should
>> > > only have a soft dependency on CDI at most.
>> > >
>> > > C. Technologies should provide features that work well with CDI
>> > > without duplicating any functionality in CDI. Use CDI wherever
>> > > it fits. The implementation may have a hard dependency on CDI
>> > > and may require CDI even when used in a standalone environment.
>> > >
>> > > I'm sure you can think of other options as well.
>> > >
>> > > What advice do you think we should give to other Java EE specs?
>> >
>> >
>> >
>> >
>> > --
>> > Antonio Goncalves
>> > Software architect and Java Champion
>> >
>> > Web site | Twitter | LinkedIn | Paris JUG | Devoxx France
>>
>>
>
>
> --
> Antonio Goncalves
> Software architect and Java Champion
>
> Web site <http://www.antoniogoncalves.org> | Twitter<http://twitter.com/agoncal>|
> LinkedIn <http://www.linkedin.com/in/agoncal> | Paris JUG<http://www.parisjug.org> |
> Devoxx France <http://www.devoxx.fr>
>