[cdi-dev] [JBoss JIRA] (CDI-414) Support for "self" injection or intercepted self invocation

[Antoine Sabot-Durand (JIRA)]

    [ https://issues.jboss.org/browse/CDI-414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13164839#comment-13164839 ] 

Antoine Sabot-Durand commented on CDI-414:
------------------------------------------

bq.Not sure it is really worth all the hassle. At the end this feature is very rarely used.

It is not used since it's  not possible today. It's a new feature proposal

bq. Of course it IS used and sometimes needed. But for those occasions there is the well-known pattern of simply using self-injection manually.

IMO Self-Injection is not a design pattern, it's a smelly trick introduced to EJB implementation limitation
The number of average joe who think that interceptor will be triggered from internal call is countless. Check on Stack Overflow

bq. PS: 'business method' is a well defined term in the EJB spec.

What's the interest of this remark? CDI is not EJB and had to give its own definition of "business method" since Interceptor spec doesn't.

> Support for "self" injection or intercepted self invocation
> -----------------------------------------------------------
>
>                 Key: CDI-414
>                 URL: https://issues.jboss.org/browse/CDI-414
>             Project: CDI Specification Issues
>          Issue Type: Bug
>          Components: Resolution
>            Reporter: arjan tijms
>             Fix For: 2.0 (discussion)
>
>
> Many features of CDI and EJB work by means of a proxy that intercepts calls and adds 'aspects'. In Java it's however not possible to decorate the {{this}} pointer, so methods called on the same bean instance from within a method in the bean do not get their 'aspects' applied.
> This is a well known limitation, but in EJB it's possible to work around this by injecting a bean into itself. E.g.
> {code}
> @Stateless
> public class Foo {
>     @EJB
>     private Foo self;
>     // ...
> }
> {code}
> Also see http://adam-bien.com/roller/abien/entry/how_to_self_invoke_ejb
> Unfortunately using CDI and {{@Inject}} this doesn't work. Weld for instance fails the deployment and logs:
> {noformat}
> WELD-001443 Pseudo scoped bean has circular dependencies.
> {noformat}
> See also: http://adam-bien.com/roller/abien/entry/inject_vs_ejb
> Although there are workarounds, it would be great if {{@Inject}} in combination with CDI could support self injection as well.
> With that projects migrating from {{@EJB}} to {{@Inject}} can do so more easily and the capability can be convenient for new projects as well (e.g. calling two separate {{@Transactional}} methods from a single method without being required to create a new bean).



--
This message was sent by Atlassian JIRA
(v6.4.11#64026)