users@jsr311.java.net

Re: ApplicationConfig and OSGi

From: Reto Bachmann-Gmür <reto_at_gmuer.ch>
Date: Mon, 28 Jul 2008 14:42:15 +0200

Thanks Bill, using the classloader provided in the instance of Class is
the solution.

Cheers,
reto

Bill Burke wrote:
>
>
> Paul Sandoz wrote:
>> Hi Reto,
>>
>> Reto Bachmann-Gmür wrote:
>>> Hello
>>>
>>> Trying to use jax-rs in an OSGi environment we imagine bundles
>>> providing web applications by exposing instances of
>>> ApplicationConfig. However the jsr311 implementation residing in
>>> another bundle cannot instantiate the classes of the bundle
>>> providing the application.
>>>
>>
>> I know very little about the technical aspects of OSGi but would not
>> the same problem occur for a web application bundle referring to a
>> servlet class in the web.xml that needs to be instantiated by servlet
>> implementation residing in a different bundle?
>>
>> And also for Web service endpoints, EJBs and JAXB beans when
>> unmarshalling.
>>
>
> Why wouldn't JAX-RS be able to instantiate instances in an OSGi
> environment? You are getting actual references to classes and the
> JAX-RS runtime could do:
>
> pushClassLoader(resourceClass.getClassLoader());
>
> Object resource = resourceClass.instance();
> invoke();
>
> popClassLoader();
>
> If all else fails, you could change your OSGi bundle to export the
> required classes.
>
> In JBoss, each deployed bundle has its own classloader assigned to it
> (either a unique one or shared one depending on configuration). We
> register this classloader along with component metadata on deployment
> (components like EJB, Spring, etc.) to the subsystems that manage the
> deployment (like an EJB container). I can't really speak to how other
> OSGi and OSGi-like implementation would work, but there are very few
> ways to skin a cat.
>
> Bill
>