Ability for a ServiceProvider to fail with an exception

[ljacomet]

When working on ehcache/ehcache3#1710 we simplified the lifecycle between client and server by moving bits of configuration into the entity creation. However, we had to do some configuration tricks between the entity and the corresponding state service as we cannot fail service retrieval, there is not supported exception path.

Could we consider adding a ServiceCreationException or similar when a ServiceProvider knows that the configuration cannot be honoured?

[jd0-sag]

Just to be clear, is this in initialize (operating on ServiceProviderConfiguration) or getService (operating on ServiceConfiguration)?

I assume you mean the getService case.

The only concern I have with this whether or not we will need a way to handle multiple ServiceProvider instances proving the same service type. If so, we would probably change the rule from "only one provider per type" to "only one non-null response from getService per type". In that situation, there would be 2 meanings of failure from this call.

[ljacomet]

@jd0-sag Indeed, it is getService. For the multi ServiceProvider case, we could rely (not ideal I admit) on a specific exception to mean I handle this type but can't answer this request as opposed to I am supposed to handle this but failed to for non recoverable reasons.