We've also run into this problem but didn't want to use any
technology/framework other than RCP, DS and OSGi. Our solution so far is rather
a workaround, but works fine for us so far:
We've created a generic service listener interface and a generic
ServiceTracker:
public interface IGenericServiceListener<S> {
public void bindService(S service);
public void unbindService(S service);
}
public class GenericServiceTracker<S> extends ServiceTracker {
private S service;
private List<IGenericServiceListener<S>> serviceListener;
private final Class<S> clazz;
public GenericServiceTracker(BundleContext context, Class<S> clazz) {
super(context, clazz.getName(), null);
this.clazz = clazz;
this.serviceListener = Collections.synchronizedList(new
ArrayList<IGenericServiceListener<S>>());
}
@Override
public Object addingService(ServiceReference reference) {
service = clazz.cast(super.addingService(reference));
informListener();
return service;
}
private void informListener() {
for (IGenericServiceListener<S> listener : serviceListener) {
listener.bindService(service);
}
}
public void addServiceListener(IGenericServiceListener<S>
serviceListener) {
// inform immediately if service available
if (this.service != null) {
serviceListener.bindService(service);
}
this.serviceListener.add(serviceListener);
}
}
The generic service interface and ServiceTracker are reusable. Next is the code
you have always to write when interested in a specific service:
The activator in your RCP plug-in has to implement a specific
addServiceListener method, e.g.
public static void addFacilityServiceListener(
IGenericServiceListener<IFacilityService> listener) {
this.facilityServiceTracker.addServiceListener(listener);
}
And you have to start the ServiceTracker within the Activator-start() method:
this.facilityServiceTracker = new
GenericServiceTracker<IFacilityService>(context, IFacilityService.class);
facilityServiceTracker.open();
Last thing to do is your RCP-ViewClass has to register a serviceListener e.g.
within the constructor:
public MyRCPView() {
MyActivator.addFacilityServiceListener(new
IGenericServiceListener<IFacilityService>() {
@Override
public void bindService(IFacilityService service) {
// TODO Auto-generated method stub
}
@Override
public void unbindService(IFacilityService service) {
// TODO Auto-generated method stub
}
});
}
Or you can implement the listener interface this way and have bindService() and
unbindService() methods directly within your ViewClass
public class MyRCPView extends ViewPart implements
IGenericServiceListener<IFacilityService>
Regards,
Eugen
Am 02.11.2010 um 13:34 schrieb O'Flynn, Dennis:
> Another dependency-injection approach is Spring. Martin Libbert provided a
> way to bridge extension points w/ spring beans. See his blog at:
> *
> http://martinlippert.blogspot.com/2008/05/dependency-injection-for-extensions.html
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Neil Bartlett
> Sent: Tuesday, November 02, 2010 7:11 AM
> To: Equinox development mailing list
> Subject: Re: [equinox-dev] Eclipse ViewPart and OSGI Declarative
> Servicesproblem
>
> Hi Richard,
>
> This is a rather challenging area, because the lifecycles of services
> and extensions are completely unrelated. As you've noticed, creating a
> component with DS does not mean it will be used by the extension
> registry. Indeed it cannot be, because the extension registry is more
> like a factory where new instances are created each time they are
> needed.
>
> I created a small framework to help with this kind of thing:
> http://github.com/njbartlett/extensions2services. Please be sure to
> read the manual (in PDF), because it helps to describe the background
> of the problem, even if you decide not to adopt my solution.
>
> Other possible solutions, which all use or include a
> dependency-injection approach, are as follows:
>
> 1) Eclipse Riena -- however Riena does a lot of other stuff that I
> don't really understand
> 2) Peaberry is based on Guice
> 3) Eclipse 4.0 ("e4") uses dependency injection everywhere, but this
> is not much use to you if you are using 3.x.
>
> Regards,
> Neil
>
>
> On Mon, Nov 1, 2010 at 9:17 PM, Richard Catlin
> <[email protected]> wrote:
>> I have a ViewPart which depends on an OSGI Declarative Service.
>>
>> I have it configured properly so that the service is injected into the
>> ViewPart via a bind method. I can debug and see that this is working.
>>
>> The problem I am having is that a new instance of the ViewPart is being
>> instantiated for viewing and that the instance that was injected is not
>> being used.
>>
>> Any help is appreciated.
>>
>> Thanks.
>> Richard Catlin
>>
>> _______________________________________________
>> equinox-dev mailing list
>> [email protected]
>> https://dev.eclipse.org/mailman/listinfo/equinox-dev
>>
>>
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