如何处理Spring集成流（JavaDSL）的事务

如何在spring集成（JavaDSL）中为完整流定义事务

通过Spring集成，我们可以定义一个示例流：

@Bean
public IntegrationFlow myMessageFromMessageAmqpInboundFlow() {
    return IntegrationFlows.from(myInboundChannel)
            .transform(aMessageTransformer)
            .transform(anotherMessageTransformer)
            .channel(anOutputChannel)
            .get();
}

我需要一个超过整个流程的事务。当前，当我使用“aMessageTransformer”访问数据库时，事务将在处理此消息转换器后关闭。 但我需要一个在处理“anotherMessageTransformer”时仍未提交的事务

我希望我只需要添加一个“@Transactional”（或@Transactional（propagation=propagation.REQUIRED，readOnly=true））

但这会导致“anotherMessageTransformer”中出现“无会话异常”

您需要遵循这一点，因此将其添加到您的流程中：

.transform(aMessageTransformer, e -> e.transactional(true))

其中，

.transactional（）

是关于：

/**
 * Specify a {@link TransactionInterceptor} {@link Advice} with default
 * {@code PlatformTransactionManager} and {@link DefaultTransactionAttribute} for the
 * {@link MessageHandler}.
 * @param handleMessageAdvice the flag to indicate the target {@link Advice} type:
 * {@code false} - regular {@link TransactionInterceptor}; {@code true} -
 * {@link org.springframework.integration.transaction.TransactionHandleMessageAdvice}
 * extension.
 * @return the spec.
 */
public S transactional(boolean handleMessageAdvice) {

TransactionHandleMessageAdvice

表示：

* When this {@link Advice} is used from the {@code request-handler-advice-chain}, it is applied
 * to the {@link MessageHandler#handleMessage}
 * (not to the
 * {@link org.springframework.integration.handler.AbstractReplyProducingMessageHandler.RequestHandler#handleRequestMessage}),
 * therefore the entire downstream process is wrapped to the transaction.

---

首先，您的消息流是否发生在同一个线程中？

* When this {@link Advice} is used from the {@code request-handler-advice-chain}, it is applied
 * to the {@link MessageHandler#handleMessage}
 * (not to the
 * {@link org.springframework.integration.handler.AbstractReplyProducingMessageHandler.RequestHandler#handleRequestMessage}),
 * therefore the entire downstream process is wrapped to the transaction.