I'm new whith OSGi, but it is interesting. Is it possible to interact between osgi bundles and java application? If it is possible, how? thanks!
The context is that I have a big Java SE application(author is another programmer) with many dependencies. First my goal is to add new functionality and second - change architecture. I'll try to use OSGi, but I don't want to write code twice, for that reason I want to write new code now as bundles. But use this new functionality from the old application.
I see OSGi as a structuring technology. You can use it to define the component structure of your application. So all of your app is effectively a collection of OSGi bundles. Hence interaction is not a problem, just different bits of your app interating in the normal way.
[Edited following comment clarification.]
You have a fundamental decision: is your OSGi code going to execute in the same process as the original or in a seperate process?
Separation implies freedom to structure the new code as you wish, exploiting OSGi, but at the cost of interprocess communication complexity and performance overheads. It's pretty likely that you will end up making substantial changes to the existing app in order to support remoting in some form. I don't see this as a great approach unless your OSGi code happens to be some kind of re-usable service that perhaps other remote clients would use.
If in the same process then I'd say that you need to bite the bullet and say that this is going to be a OSGi application. The amount of effort to take an existing app and make it run in OSGi need not be excessive.
Suppose you treated the existing application as one huge OSGi bundle? There would be some work on initialisation, but would the rest "just work"? If you do this as the first step then the real re-architecting and modularisation of the existing app is deferred. You then just expose the interfaces your new modules need, and where necessary consume services provided by the new modules. Immediately you are getting OSGi benefits by structuring the dependencies.