如何在 Spring Boot 中使用同步工厂配置出站通道适配器

Question

Spring Boot 中的以下出站通道适配器配置相当于什么？假设定义了messageChannel、taskExecutor 和synchronizationFactory。

    <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>

带有@Poller 注释的@ServiceActivator 似乎没有事务同步工厂的选项。 PollerMetadata 有一个选项，但我不确定如何将该实例连接到 @ServiceActivator。

在这种情况下需要同步工厂，因为它是一个基于 DB 的通道，有多个线程从中读取。

Answer 1

类似这样的：

@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;
}

您也可以考虑开始学习 Spring Integration Java DSL：https://docs.spring.io/spring-integration/reference/html/dsl.html#java-dsl。相同的配置看起来像这样：

@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();
}