[weld-dev] standard servlet context attribute for the BeanManager

[Dan Allen]

At the last Seam team meeting, the issue came up (once again) of how to get
the BeanManager from a non-contextual resource. The reality is that there
are certain lifecycle classes in Java EE that did not get categorized as
components (e.g., PhaseListener) and therefore do not support injection.
They are "outside" of CDI. We are working on an SPI for JSF to make these
classes CDI beans, but there will always be other cases.

In the current version of the spec, the standard way of looking up the
BeanManager is to use JNDI. However, JNDI is not consistently supported in
environments for which we want to write portable extensions (whether we like
it or not, people use servlet containers). Weld puts the BeanManager in a
servlet context attribute equal to the FQCN of BeanManager. Pete suggested
that we submit a change request to have this location standardized when
running in a servlet environment.

With this change, the BeanManager can be obtained as follows:

BeanManager manager = (BeanManager)
getServletContext().getAttribute(BeanManager.class.getName());

This requires no change in Weld, since Weld is already doing this.

-Dan

-- 
Dan Allen
Senior Software Engineer, Red Hat | Author of Seam in Action
Registered Linux User #231597

http://mojavelinux.com
http://mojavelinux.com/seaminaction
http://www.google.com/profiles/dan.j.allen
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/weld-dev/attachments/20100322/8310b895/attachment.html