[javaee-spec users] Re: DataSourceDefinition

From: Josh Juneau <>
Date: Tue, 26 Aug 2014 19:55:11 -0500

The continued pattern of applying more standards across the platform is beneficial to everyone. I think that it is clear to see from the responses in this thread that there are many use cases for this annotation, in particular. I am in the camp of those who do not use this feature for production, but I can see how it may be useful for some situations.

Perhaps adding a note in the JavaDoc regarding best practices would be beneficial. However, stating blatantly that this should not be used in production is perhaps not the best approach since some are finding good use-cases for a production environment.

Josh Juneau

> On Aug 26, 2014, at 4:55 PM, arjan tijms <> wrote:
>> On Tue, Aug 26, 2014 at 8:22 PM, Romain Manni-Bucau <> wrote:
>> 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,
> Arjan