Hi Jimi,
Provider classes, such as the JAXB message body writers, are looked up  
using the com.sun.jersey.spi.service.ServiceFinder and in that source  
you will find the use of the thread context class loader.
I cannot explain the class loading differences in this respect with  
JAXB, i guess Jira does something a little different to isolate  
certain libraries, and the JAXB implementation is not visible from the  
thread context class loader?
On Aug 6, 2010, at 3:07 PM, Jimi Hullegård wrote:
> Hi Moises,
>
> No, my JAXBContextResolved wasn't in the same package as my  
> resourses, since I haven't seen any such directive in any Jersey/ 
> JAXB-documentation. But I just tried that and it didn't make any  
> difference.
>
> And no, I have no Application class. And I have no idea on what that  
> class should contain, and how I should make it available for Jersey.  
> All Application-related discussions seems to asume that this takes  
> place in a web application. But I use Jersey as a client only, and I  
> have no servlet or any web.xml or something like that.
>
You need to register your ContextResolver<JAXBContext> implementation  
explicitly with the client, as follows:
   ClientConfig cc = new DefaultClientConfig();
   cc.getClasses(MyContextResolver.class);
   Client c = Client.create(cc);
Paul.