Access metadata from DataConnector

[Tom Zeller]

> You would have to inject a facade to the MetadataResolverService. I don't know if that's feasible. The danger comes from circularity, but I don't think the metadata layer has any dependency on the attribute resolver.
> 
> I believe you would need to inject a bean like this into the connector:
> 
> <bean id="shibboleth.MetadataResolver"
>        class="net.shibboleth.idp.saml.metadata.impl.ReloadingRelyingPartyMetadataProvider"
>        c:resolverService-ref="shibboleth.MetadataResolverService" />
> 
> The beans in services-system.xml aren't really public, and that class certainly isn't. So strictly speaking, no, it's not supported. But we can probably make a determination about committing to the service bean IDs.

Just a thought that in case injection is a hassle for customizers, maybe AbstractResolverPlugin or a subclass should implement ApplicationContextAware.