Apache Felix Bundle Plugin Frequently Asked Questions

When I embed a dependency why do I see duplicated content?

Having two copies of classes, both unpacked and embedded as jars, is a sign that your Embed-Dependency and Export-Package instructions are overlapping. Export-Package tells BND to pull in classes found in the named packages from the build classpath and add them to the bundle, Embed-Dependency tells BND to embed (or inline if enabled) whole artifacts in the bundle.

so say I have:

Export-Package: org.objectweb.asm.*

and I have the asm artifact as a compile scope dependency, then I would see the org.objectweb.asm classes unpacked in the bundle, ie. pulled in by BND.

say I now decide to embed asm as a jar, for example with:

Embed-Dependency: *;scope=compile|runtime

I would now see the asm artifact embedded inside bundle - but I would also see the unpacked classes from before, because I'm still asking BND to pull them in (you will probably also see split package warnings during the build).

ok - so how do I embed asm as a jar, but mark its packages as exported without pulling in the unpacked classes... well, there is another export instruction added for exactly this reason:

-exportcontents: org.objectweb.asm.*

(this is <_exportcontents> in the POM because a tag can't start with '-')

this instruction is merged with Export-Package, after BND has decided on the content of the bundle - that is, it works just like Export-Package except that it won't alter the content of the bundle.

So by removing org.objectweb.asm.* from Export-Package and using the -exportcontents instruction instead along with Embed-Dependency, I can now embed the asm artifact in my bundle and export its packages:

Embed-Dependency: *;scope=compile|runtime
-exportcontents: org.objectweb.asm.*