[javaee-spec users] Re: DataSourceDefinition

From: arjan tijms <>
Date: Tue, 26 Aug 2014 23:55:34 +0200

On Tue, Aug 26, 2014 at 8:22 PM, Romain Manni-Bucau <>

> to enforce your "nobody uses it" the main issue is it is not usable
> for prod - often not the same team handles config and packaging

There are undoubtedly situations where there are different teams doing
development and configuration (simplest case is externally obtained
applications that need to be integrated into an intranet), but it's also
often the case that it does concern the same team.

The beauty of Java EE is that both cases can be supported; the data source
can be defined using standardized embedded code/configuration, or it can
done via non-standard external means. Hopefully a future Java EE version
can also define a standardized external way. In most cases it's now a
fairly simple change to go from embedded to external or the other way
around and the majority of the code is completely oblivious to this change.

This means theoretically a beginner can prototype an app using the embedded
data-source element in web.xml. Prototypes have a tendency to grow into
production apps, and at some point when the app and requirements have grown
one can simply remove the single data-source element from web.xml again and
define the data source externally. Then when the team eventually matures
and fully understands when to separate things and when not, the data-source
element may simply be added again in order to simplify things. All this
without ever changing any code that depends on the data source.

> - and
> portable since it doesn't integrate with common Java solution (common
> jdbc config - think to [dbcp] for surely the most known one).

I'm not entirely sure what you mean here. Do you perhaps mean to say that
Tomcat doesn't support @DataSourceDefinition?

Every Java EE server now certainly supports it. The Java EE 6 TCK probably
didn't test this facility thoroughly, as a couple of early (but certified)
Java EE 6 products indeed didn't support it well at first, but since some
time the support is pretty good (see e.g.
We also tested our kick off app (see and on a number of
servers and @DataSourceDefinition worked everywhere.

I think it's thus fairly portable ;)

Kind regards,