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[equinox-dev] Declarative Services and bundle lifecycle


I have been trying out declarative services by porting the org.eclipse.core.jobs bundle to use it.  The big potential advantage of using DS is that I can remove or at least isolate all "containerisms" from my bundle. Ideally the Java code in my bundle is entirely ignorant of the OSGi core and the declarative services runtime (SCR). This makes the code reusable, and easy to use either standalone or inside some other application container (spring, etc).

This works very well for both service registration and lookup.  In my refactored code, the only external dependencies are on the two optional services used by jobs: DebugOptions and PackageAdmin. These can be injected at runtime if desired, either by DS, some other application container, or manually.

The one sticking issue is application lifecycle.  The only way (as far as I can see) that my component can participate in the startup and shutdown sequence is to implement DS-specific methods activate(ComponentContext), and deactivate(ComponentContext).  Ideally I would like to define the activate and deactivate method names in my component definition XML, and not have any exposure to those DS interfaces (which I don't need in this case).  I can participate in startup quite easily by adding code to my component object's constructor, but I see no solution for shutdown.  Does anyone know of a way I can make my bundle participate in the shutdown sequence without adding a dependency on either OSGi or SCR? (for example, to clean up threads I have created, withdraw listeners, etc). One could of course define another bundle that can tell the jobs bundle to shutdown at the right time, but it seems like overkill.

For anyone interested in following along with my experiments with DS in org.eclipse.core.jobs, see:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=159788

John