users@javaee-spec.java.net

[javaee-spec users] [jsr342-experts] Re: custom injection annotations

From: Pete Muir <pmuir_at_bleepbleep.org.uk>
Date: Tue, 6 Nov 2012 18:18:43 +0100

Hi Antonio

Actually, Java SE support is planned for CDI 2.0. I'll be writing the full proposal for this up this month, and will be sure to send a copy to you for review!

Pete

On 6 Nov 2012, at 09:53, Antonio Goncalves wrote:

> Hi all,
>
> I am the opposite of Markus on this one. I don't what to ask myself too many questions : need to inject a persistence context ? @Inject PersistenceContext. Need to inject an EJB ? @Inject MyEJB... and so on. I'm already disappointed to see @Context in JAX-RS. The programming model should be as easy as possible.
>
> Then comes the "I don't want to depend on CDI". This to me sounds a bit strange. CDI 1.1 is standardizing bootstrapping in Java SE, so what's the issue ? If the Batch JSR needs CDI outside EE it just bootstraps CDI in Java SE. Then, depending on CDI only really means depending on another external jar (piece of cake for Maven)
>
> I would like to see less custom technical annotations (let's use @Inject when we can) and in favour of more business annotation that developers can create (thanks to Stereotypes and Qualifiers)
>
> Antonio
>
>
> On Tue, Nov 6, 2012 at 6:48 AM, Markus Eisele <myfear_at_web.de> wrote:
> Hi Bill/All,
>
> Still very much split myself. I'm in favor of CDI. I simply don't like to see @Inject all over the place.
> We already have a ton of custom annotations (e.g. @EJB) and if we treat them as a legacy artifact only we will probably end up with a programming model that needs good naming conventions (again) to be helpful.
>
> @Inject
> private MyBoundary boundaryEJB;
>
> @Inject
> private JobContext batchContext;
>
> This moves the problem to the user but should be solved in the platform. Having custom injection annotations makes this more readable and easier to follow in the code (at least for me).
>
> I would like to see the expansion of use of CDI stereotypes (aka meta-annotations / stacked stereotypes) and require every EE spec to provide a CDI based injection annotation.
> They should be free to provide additional ways for supporting standalone environments (e.g. via additional @Qualifiers).
>
> - M
>
>
> On 6 November 2012 01:10, Bill Shannon <bill.shannon_at_oracle.com> wrote:
> I'd like to follow up on an issue we raised at the Java EE 7 BOF
> about the use of custom injection annotations.
>
> For example, should the Batch spec define
>
> @BatchContext
> private JobContext ctx;
>
> or should it use
>
> @Inject
> private JobContext ctx;
>
> The former is effectively a custom injection annotation unrelated to CDI.
>
> The latter introduces a dependency on CDI.
>
>
> In your opinion, which is preferred? It seemed that the EE 7 BOF audience was
> pretty evenly split on this one, and I can see arguments for either position.
>
> If @Inject is preferred, should we allow custom annotations at the discretion
> of the spec author, or should we disallow custom annotations entirely?
>
> If custom injection annotations are allowed, should CDI make it easy to
> define them, e.g., using something like:
>
> @Stereotype
> @Inject
> public @interface BatchContext { }
>
> If CDI supported this easily, applications could even define their own
> injection annotations.
>
> Should custom injection annotations be a legacy artifact that we need
> to continue to support, or should we recognize it as a part of the
> Java EE programming model and use it widely?
>
>
>
>
> --
> Antonio Goncalves
> Software architect and Java Champion
>
> Web site | Twitter | LinkedIn | Paris JUG | Devoxx France