[hibernate-dev] Concept of "service availability"

[Steve Ebersole]

I am not familiar enough to know how this hooks in with OSGi. 
StrategySelector is already pushed to master, if you want to incorporate 
what this might look like using that I will certainly take a look.


On 08/28/2012 03:33 PM, mailing at bibbernet.org wrote:
> I had a similar problem before:
>
> In an osgi project we needed the ability to extend a main system with
> functionality provided in addon bundles
> We developed a main system which could be extended and complemented with
> extenders of several kinds.
>
> The main system provided (exported) a tree of marker interfaces like
>
> public interface ExtenderMarker {};
> public interface TypeAExtender extends ExtenderMarker
> public interface TypeBExtender extends ExtenderMarker
> ....
>
> and had a "helper" which scans services, tracks services and initially
> scans the framework for interesting services (started from the bundle
> activator of the main system).
>
> The extender bundles only implemented the extenders and registered OSGI
> services with the ExtenderMarker interface and maybe also the concrete
> interface. They had no more tasks to do.
>
> Now the main system could "use" the extenders which got registered by
> the "helper" and the "helper" was handling the live cycle events, etc.
>
> Simple approach based on the whiteboard pattern.
>
> - Martin

-- 
steve at hibernate.org
http://hibernate.org