How to read messages from a queue channel inside a service-activator?

[werder85]

I'm trying to read messages from a queue channel inside a service-activator. I know how to read these messages in the main thread (i.e. where the applicationContext is initialized), where I could just get the instance of the channel and then call the receive method. The problem is that inside the service activator I don't have access to the applicationContext...
Can someone halp me solve this problem?
Thanks a lot.

[oleg.zhurakousky]

All you need is a poller configured in service-activator. The poller will poll for messages from the queue.

<service-activator input-channel="someQueueChannel"
        output-channel="output">  
     <poller receive-timeout="30000">
         <interval-trigger interval="10"/>
     </poller>
 </service-activator>

Just do a string search in the documentation for 'poller', there are plenty of samples.

[werder85]

The service activator I was talking about is already receiving messages from a direct channel.
Now, I want, when the service activator receives a message from the direct channel, to read all messages from the queue channel, then modify the message received from the direct channel and send it out on the output-channel.

[Mark Fisher]

You can always inject the channel instance into the service object that you are invoking through the service activator using standard DI.

However, could you provide a bit more detail about the use-case? Specifically, what is contained in the Message that is received from the DirectChannel? Is that only being used as a trigger to drive the polling consumer?

[werder85]

Problem solved.

I've just injected the queue-channel inside the service-activator....

Thanks a lot again.

[Mark Fisher]

Glad to hear you have a working solution. However, can you please describe the use-case? It sounds like it might be solvable in a different way... or at least something that we could address in 2.0. In most cases, your service object should not even be aware of the messaging API.

Thanks,
Mark