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No DynamicImport-Package in Scoped Bundle? [message #663591]

Tue, 05 April 2011 18:03

Aaron

Messages: 21
Registered: February 2011

Junior Member

I'm using Jabsorb to do JSON marshalling/unmarshalling within my Virgo OSGi application. I created an OSGi bundle for Jabsorb and found that I had to add DynamicImport-Package=* to its manifest because Jabsorb uses Class.forName(String name) during unmarshalling. If you need to understand why Class.forName(String name) is an issue, read this. I understand there are other ways to deal with this issue, but DynamicImport-Package seems like a reasonable solution for a serialization library.

Anyway, DynamicImport-Package for my Jabsorb bundle seems to work great until I use it within an application defined by a scoped plan. It works fine without a plan and it works fine within an application defined by an un-scoped plan. To clarify, Jabsorb is not referenced directly in my plan, but it is used as a runtime dependency via OSGi dependency resolution.

I'd like to use a scoped plan to get the nice Virgo logging benefits that I only seem to get with scoped plans.

Any ideas what could be going on here?

Thanks,
Aaron

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Re: No DynamicImport-Package in Scoped Bundle? [message #663609 is a reply to message #663591]

Tue, 05 April 2011 20:23

Glyn Normington

Messages: 1222
Registered: July 2009

Senior Member

Unless you include Jabsorb in the scoped plan, it will reside outside the scope and its dynamic package import will be unable to wire to the packages exported by the bundles in the scoped plan.

BTW please note dynamic import * is rather an anti-pattern. In particular, it cannot cope when it needs to import a package of which there are multiple versions available in the framework: you'll be lucky if you get the version you need.

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Re: No DynamicImport-Package in Scoped Bundle? [message #663897 is a reply to message #663609]

Wed, 06 April 2011 18:19

Aaron

Messages: 21
Registered: February 2011

Junior Member

Thanks for the information, Glyn. That makes sense. I didn't understand that bundles resolved as dependencies of a plan were not within the plan scope.

As far as DynamicImport-Package:* goes, is there a better way to deal with that situation? I looked at using fragments, but it seems weird to have to create and register a fragment for every library containing classes that need to be serialized.

Thanks,
Aaron

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Re: No DynamicImport-Package in Scoped Bundle? [message #664294 is a reply to message #663897]

Fri, 08 April 2011 10:07

Glyn Normington

Messages: 1222
Registered: July 2009

Senior Member

Aaron wrote on Wed, 06 April 2011 19:19

Unless Jabsorb also uses the thread context class loader, possibly not. In that scenario, fragments would have a similar limitation to dynamicimport-package: * - you would be limited to one version of each package that needs to be serialised.

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