Hi! I would like your opinion on a specific issue we're encountering when using iPOJO. For API compatibility reason, we're inclined to use only abstract classes, not interfaces. The reason behind this is that we want pieces of software based against any further version of the API to remain compatible with previous API versions even if methods have been added. Using abstract methods, we provide default implementations for every new method, ensuring that pieces of software developped using this API remain usable.
We noticed that, by default, iPOJO prints a warning for @Requires dependencies: [WARNING] package.Class : Proxies cannot be used on service dependency targeting non interface service specification package.AbstractClass It is my understanding that disabling proxy use for the corresponding dependency disable this warning, but I would like to understand what this involves. First and foremost, what exactly are proxies for? Is this related to the Nullable objects which provide empty implementations of optional and not available dependencies, avoiding null checks on the component side? What's the downside of not using proxies: having to check for null optional dependencies if what I just said is relevant? Does disabling proxy use also mean disabling the dynamic dependency injection (Dynamic / Static / Dynamic-Priority)? I don't think so, but I would like to make sure. Finally, and maybe I should have started, is there a reason not to be using abstract classes for service specifications with iPOJO, and more generally, OSGi? I know there are a lot of questions there, but I'm sure most can be answered quite easily :)) Thanks a lot for any piece of information you may provide me with ;) Regards, Rémy
