ServiceActivator methods not discovered if named "start", "stop" or "isRunning"

[grubeninspekteur]

Affects Version(s): 5.1.0

Bug report

If a service activator has methods named "start", "stop" or "isRunning", these cannot be automatically discovered by SI. The activating method must be specified explicitly.

Target object of type [...] has no eligible methods for handling Messages.

This happens due to these methods being filtered in MessagingMethodInvokerHelper.java#L827

[garyrussell]

That is by design.

Can you explain your use case?

If you are trying to control the lifecycle of endpoints, the proper way to do that is via the Control Bus.

Send a message to the control bus with someEndpoint.stop(), etc.

[grubeninspekteur]

We just happened to name a method of an endpoint POJO "start". The error message was not helpful in finding the cause; If these method names are not allowed, maybe we should document it in Service Activator?

[garyrussell]

Maybe we should tighten up the filter to also check that there are no parameters on those methods (or stop(Runnable)).

@artembilan WDYT?

[artembilan]

Good catch! And I guess we just don't have any documentation on the matter.
I think we can just apply a ControlBusMethodFilter for discovered methods to check their legitimacy.
If method fail, we definitely should say something in the error about Control Bus.
And of course in the end we have to document this limitation.

Does it sound OK?

[grubeninspekteur]

Sounds good!

[artembilan]

So, since we all are OK with proposal, I wonder, @grubeninspekteur , if you can come up with a contribution on the matter: https://github.com/spring-projects/spring-integration/blob/master/CONTRIBUTING.adoc

[garyrussell]

I'll take it since M4 is tomorrow.