Here I agree with Jeff. Separating API and implementation on package level is crucial on several different ways. Not only is it a cleaner design, it also gives you the chance to later refactor your code and move the implementation into a new bundle very easily (if you haven't done so already).
The question on using different bundles for api/spi/implementation or not is hard to answer in a general manner. I usually ask myself, who is going to use it, how frequently and how likely is it, that there will be several implementations. If it is just internally used, not a major service and not likely to have different implementations, why should I create a (and maintain) a completely different bundle with maybe just one or two classes in it? I think, it is a mixture of common sense and experiences, but if I'm in doubt, I don't separate them. Refactoring is your friend and if the application is done right, it is no problem at all. Just remember to use version ranges on package dependencies and package versioning according to the OSGi Spec. Cheers, Mirko On Mon, Jun 2, 2008 at 3:29 PM, Toni Menzel <[EMAIL PROTECTED]> wrote: > You should put API and implementation into separate bundles. > This decouples the specification (api) from one or even multiple > implementations and allows implementation changes without restarting the > framework (the osgi way). > > When it comes to exporting, well you just export what you either really want > to export (usually just api/spi stuff) or you imported yourself (known as > package substitution). > > There are hardly reasons to include the api into the implementation's bundle. > Instead you must be aware of class loading issues if you expose services. > > "Do you even recommend to separate API and SPI on package level?" yes. same > as above. (separation of concerns). > > /Toni > > -------- Original-Nachricht -------- >> Datum: Mon, 2 Jun 2008 15:06:39 +0200 >> Von: "Peter Niederwieser" <[EMAIL PROTECTED]> >> An: osgi-dev@mail.osgi.org >> Betreff: [osgi-dev] Put API/SPI/implementation into separate bundles? > >> When building an OSGi-based system, do you recommend to put a >> component's API/SPI/implementation into separate bundles, or is it >> good enough to put them into separate packages (exporting only API and >> SPI)? Has the "separate bundle" approach advantages when it comes to >> updating/replacing bundles at runtime? Do you even recommend to >> separate API and SPI on package level? >> >> Cheers, >> Peter Niederwieser >> _______________________________________________ >> OSGi Developer Mail List >> osgi-dev@mail.osgi.org >> https://mail.osgi.org/mailman/listinfo/osgi-dev > _______________________________________________ > OSGi Developer Mail List > osgi-dev@mail.osgi.org > https://mail.osgi.org/mailman/listinfo/osgi-dev > _______________________________________________ OSGi Developer Mail List osgi-dev@mail.osgi.org https://mail.osgi.org/mailman/listinfo/osgi-dev
