Re: [equinox-dev] plugin host problem

[Fabien Autrel <fabien.autrel@xxxxxxxxxxxxxxxxxxx>]

I answer to myself as I have understood how to work around the problem.
I realize that the way I'm developing my application is not the good way 
using osgi, I might soon repackage it into a bundle.
So by changing the system property osgi.parentClassloader, I can set the 
system to use the same class loader so the cast I'm doing to get the 
service implementation is ok.

Fabien Autrel a écrit :
> Dear all,
>
> I am new to the osgi framework and I have a question.
> I have developped an application in which I want to add plugins. I 
> have chosen the osgi framework to implement that but I am now facing a 
> problem: my application manages the bundles through an instance of 
> BundleContext obtained via a call to EclipseStarter.startup();
> I have defined an interface which the plugins must implement, I have 
> developped a plugin implementing the interface, the bundle is loaded 
> and started without any problem but a  ClassCastException is raised 
> when I try to obtain the service implementation in my application 
> though this piece of code:
> IPolicyProcessorService service = (IPolicyProcessorService) 
> context.getService(serviceRefs[i]);
> where serviceRefs[i] is the ServiceReference object corresponding to 
> the plugin.
>
> If my understanding of classloaders is correct, this exception is 
> raised because the IPolicyProcessorService class file has been loaded 
> by two different class loaders in the application and in the bundle so 
> even though the loaded data on the disk is the same, I cannot make the 
> cast.
> So I understand that I could encapsulate my application in a bundle, 
> my plugin in a bundle and import the plugin interface class from 
> another bundle but it would be quite a big amount of work to modify my 
> application.
>
> So my final question is, is there a way of using the services exposed 
> by bundles from a "host" application running equinox like I'm trying 
> to do?
>
> Thank you!
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