Looking for a way to stop a DirectChannel

[artafinde]

I am looking for a way to stop a DirectChannel from getting messages
I am not using any *inbound*, just sending directly to the channel so not possible to use SmartLifecycle.
I am using Spring Integration 2.1.0.RELEASE and sending Message<String> messages using:

[..]
notificationChannel.send(message);[..]

Is there a way to pause/stop/resume the flow?

EDIT:
Or is it possible to stop/pause/resume a service activator

Thanks in advance

[Mark Fisher]

The first thing that comes to mind is to add a ChannelInterceptor and provide a configurable flag on that so that the preSend() method returns FALSE when the interceptor's flag is in the OFF position.

However, there might be a way to handle this elsewhere in the flow (upstream or downstream from the channel itself). Can you explain a bit about your flow and the rationale for being able to deactivate it?

Thanks,
Mark

[Cleric]

Hi!

pause/stop/resume the flow

is equals to

stop/pause/resume a service activator

Any message flow starts from consumer(subscriber) on the channel.
So, you go right way: you should just stop your endpoint (PollingConsumer or EventDrivenConsumer) from it's SmartLifecycle abilities.
it will be enough to add an 'id' attribute for your <service-activator> and invoke it, e.g. from <control-bus>:

<transformer input-channel="sendStopCommandChannel" output-channel="controlBusChannel"
				 expression="'@myServiceActivator.stop()'"/>

However be careful with that, you may end up with this one:

org.springframework.integration.MessageDeliveryException: Dispatcher has no subscribers for channel ...

when you unsubscribe from chennels who implement AbstractSubscribableChannel.

Hope that help

Take care,
Artem

[artafinde]

Cleric thanks for your answer, I used something similar combine what you suggested and the examples:
https://github.com/SpringSource/spri...sDemoTest.java

I am getting the controlBusChannel and sending a genericMessage to stop the serviceActivater.

The service activator is connected to

<si:channel id="notificationChannel"/>
<si:channel id="enrichingChannel"/>

so I don't think I will have problem with AbstractSubscribableChannel since both are org.springframework.integration.core.MessageChanne l (right?)

Thanks again

[Cleric]

(right?)

No

<si:channel id="notificationChannel"/>
<si:channel id="enrichingChannel"/>

Both are DirectChannel.
However you're right, I had to say so:
Be careful around SubscribableChannel implementations!

Does it work for you now?

[artafinde]

No

Both are DirectChannel.

Oops, good to know

However you're right, I had to say so:
Be careful around SubscribableChannel implementations!

Does it work for you now?

Yeah seems to be working on some first tests. I will come back if not, thanks!