如何在 spring 引导中配置带同步工厂的出站通道适配器

Question

What would be the equivalent of the following outbound channel adapter configuration in spring boot? Assuming the messageChannel , taskExecutor , and synchronizationFactory are defined.

    <int:outbound-channel-adapter id="outboundChannelAdapter" channel="messageChannel" ref="handler" method="handle">
        <int:poller task-executor="taskExecutor" fixed-delay="500" receive-timeout="500" max-messages-per-poll="10">
            <int:transactional synchronization-factory="synchronizationFactory" isolation="READ_COMMITTED"/>
        </int:poller>
    </int:outbound-channel-adapter>

The @ServiceActivator with the @Poller annotation doesn't seem to have an option for transaction synchronization factory. The PollerMetadata has an option for it but I'm not sure how to connect that instance to the @ServiceActivator .

The synchronization factory is needed in this case because it's a DB-based channel with multiple threads reading from it.

Answer 1

Something like this:

@ServiceActivator(inputChannel = "messageChannel", poller = @Poller("myPollerMetadata"))
public void handle(Message<?> message) { // Or what is your service method signature
    ...
}

@Bean
PollerMetadata myPollerMetadata(Executor taskExecutor, TransactionSynchronizationFactory synchronizationFactory) {

    PollerMetadata poller = new PollerMetadata();
    poller.setTransactionSynchronizationFactory(synchronizationFactory);
    poller.setMaxMessagesPerPoll(10);
    poller.setReceiveTimeout(500);
    poller.setTaskExecutor(taskExecutor);
    poller.setTrigger(new PeriodicTrigger(500));
    return poller;
}

You may also consider to start learning Spring Integration Java DSL: https://docs.spring.io/spring-integration/reference/html/dsl.html#java-dsl . The same config would look like this:

@Bean
IntegrationFlow myHandlerFlow(Executor taskExecutor, TransactionSynchronizationFactory synchronizationFactory) {
    return IntegrationFlows.from("messageChannel")
              .handle(handler, "handle", 
                            c -> c.poller(p -> p
                                     .fixedDelay(500)
                                     .transactionSynchronizationFactory(synchronizationFactory)
                                     .taskExecutor(taskExecutor)
                                     .receiveTimeout(500)
                                     .maxMessagesPerPoll(10)))
              .get();
}