On 4/3/06, Jacek Laskowski <[EMAIL PROTECTED]
> wrote:
I do suggest diverging a little from JSR 250 though; e.g. checked exceptions on lifecycle methods - and maybe an alternative interpretation of @Resource when using Spring
No not really. EJB reuses the annotations defined in JSR 250 for session beans. However DI is way more useful across the board than just for making Session beans. FWIW it was the Spring & Pico communities who brought DI to the mainstream; the only downside is they currently implement lifecycles using interfaces. Now we have JSR 250 we have a chance to unify EJB, Spring, Pico and SCA to use the same DI contract.
My motivation here wasn't to particularly claim anything new; it was to try and unify the communities so that if you are a POJO developer you should have one DI contract to think about - AnDI - which has nothing to do with EJB 3 per se (to avoid politics such as EJB3 v SCA or JBoss v Spring and so forth) and can be used on any POJO whether you use SCA, EJB3 or not.
So in realitly its mostly just JSR 250 really - but the paper talks about how we should deal with migration from Spring/Pico lifecycles to AnDI together with highlighting some issues of JSR 250. (e.g. I'd like to encourage a spec change among implementors by allowing @PostConstruct and @PreDestroy to throw checked exceptions).
Agreed. Though as I mentioned on the wiki page; its pretty easy to, say, make any Spring or Pico POJO support AnDI by just annotating the lifecycle interfaces these frameworks use.
Yeah. Though technically we have JSR 250 now :) though folks have never really championed using JSR 250 as a DI standard up to now. (Its often only EJB 3 folks who've spotted it :). I guess I'm trying to repurpose JSR 250 as the AnDI JSR; a standard DI contract using annotations and try to unify the POJO developer communities.
Agreed. Adding support for AnDI into XBean would be pretty easy then OpenEJB could reuse that. I ultimately want the entire Geronimo kernel to support AnDI; whether you use EJB3 or not.
On 4/3/06, James Strachan <[EMAIL PROTECTED]> wrote:
> I just blogged about this
> http://radio.weblogs.com/0112098/2006/04/03.html#a557
>
> but I thought I'd mention it here...
> http://docs.codehaus.org/display/XB/Annotation+based+Dependency+Injection
Thanks James for sharing it with us! I'm reading EJB 3.0 spec and...
> EJB 3 pretty much mandates a similar model;
...am wondering if I have already missed something as EJB 3.0 is
exactly about it rather than 'pretty much' that.
I do suggest diverging a little from JSR 250 though; e.g. checked exceptions on lifecycle methods - and maybe an alternative interpretation of @Resource when using Spring
Unless I'm mistaken,
I think you might think that the annotations might not fit EJB 3.0
yet. Is it that?
No not really. EJB reuses the annotations defined in JSR 250 for session beans. However DI is way more useful across the board than just for making Session beans. FWIW it was the Spring & Pico communities who brought DI to the mainstream; the only downside is they currently implement lifecycles using interfaces. Now we have JSR 250 we have a chance to unify EJB, Spring, Pico and SCA to use the same DI contract.
My motivation here wasn't to particularly claim anything new; it was to try and unify the communities so that if you are a POJO developer you should have one DI contract to think about - AnDI - which has nothing to do with EJB 3 per se (to avoid politics such as EJB3 v SCA or JBoss v Spring and so forth) and can be used on any POJO whether you use SCA, EJB3 or not.
So in realitly its mostly just JSR 250 really - but the paper talks about how we should deal with migration from Spring/Pico lifecycles to AnDI together with highlighting some issues of JSR 250. (e.g. I'd like to encourage a spec change among implementors by allowing @PostConstruct and @PreDestroy to throw checked exceptions).
Anyway, you're right that we've got lots of IoC containers and they
*do* tend to work behind the scenes, but they fail short wrt their
annotations that polute a code. I wish I could see a pojo that's
expected to run in two or more IoC containers. The code would surely
look horribly and its maintenance would very likely result in lots of
pain, wouldn't it?
Agreed. Though as I mentioned on the wiki page; its pretty easy to, say, make any Spring or Pico POJO support AnDI by just annotating the lifecycle interfaces these frameworks use.
It seems that with all those IoC containers the only missing piece in
the puzzle is to lay a common ground for them, e.g. as a JSR.
Yeah. Though technically we have JSR 250 now :) though folks have never really championed using JSR 250 as a DI standard up to now. (Its often only EJB 3 folks who've spotted it :). I guess I'm trying to repurpose JSR 250 as the AnDI JSR; a standard DI contract using annotations and try to unify the POJO developer communities.
> so I'm sure the XBean/OpenEJB folks will be implementing this anyway.
I'm not yet at that point in understanding what Dave B. has already
done in OpenEJB 3, but you're right it will be of high priority to
implement.
Agreed. Adding support for AnDI into XBean would be pretty easy then OpenEJB could reuse that. I ultimately want the entire Geronimo kernel to support AnDI; whether you use EJB3 or not.
--
James
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http://radio.weblogs.com/0112098/
