【Spring Transaction afterCommit 调用不生效的原因分析】

问题描述
service A 发送事件A1 提交成功之后 在afterCommit调用service B 发送事件B1 在afterCommit中未调用

环境
jdk8
spring-tx:4.3.29.RELEASE

源码调用链
TransactionInterceptor.invoke–>
TransactionAspectSupport.invokeWithinTransaction–>commitTransactionAfterReturning–>commitTransactionAfterReturning–>
AbstractPlatformTransactionManager.commit–>processCommit–>triggerAfterCommit

private void triggerAfterCommit(DefaultTransactionStatus status) {
		if (status.isNewSynchronization()) {
			if (status.isDebug()) {
				logger.trace("Triggering afterCommit synchronization");
			}
			TransactionSynchronizationUtils.triggerAfterCommit();
		}
	}


/**
	 * Return if a new transaction synchronization has been opened
	 * for this transaction.
	 */
	public boolean isNewSynchronization() {
		return this.newSynchronization;
	}

对于此场景 service B 发送事件B1后，status.isNewSynchronization() 为false 故不用再次调用

DefaultTransactionStatus属性newSynchronization的生成逻辑源码调用链
TransactionInterceptor.invoke–>
TransactionAspectSupport.invokeWithinTransaction–>createTransactionIfNecessary–>
AbstractPlatformTransactionManager.getTransaction

@Override
	public final TransactionStatus getTransaction(TransactionDefinition definition) throws TransactionException {
		Object transaction = doGetTransaction();

		// Cache debug flag to avoid repeated checks.
		boolean debugEnabled = logger.isDebugEnabled();

		if (definition == null) {
			// Use defaults if no transaction definition given.
			definition = new DefaultTransactionDefinition();
		}

		if (isExistingTransaction(transaction)) {
			// Existing transaction found -> check propagation behavior to find out how to behave.
			return handleExistingTransaction(definition, transaction, debugEnabled);
		}

		// Check definition settings for new transaction.
		if (definition.getTimeout() < TransactionDefinition.TIMEOUT_DEFAULT) {
			throw new InvalidTimeoutException("Invalid transaction timeout", definition.getTimeout());
		}

		// No existing transaction found -> check propagation behavior to find out how to proceed.
		if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_MANDATORY) {
			throw new IllegalTransactionStateException(
					"No existing transaction found for transaction marked with propagation 'mandatory'");
		}
		else if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_REQUIRED ||
				definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_REQUIRES_NEW ||
				definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_NESTED) {
			SuspendedResourcesHolder suspendedResources = suspend(null);
			if (debugEnabled) {
				logger.debug("Creating new transaction with name [" + definition.getName() + "]: " + definition);
			}
			try {
				boolean newSynchronization = (getTransactionSynchronization() != SYNCHRONIZATION_NEVER);
				DefaultTransactionStatus status = newTransactionStatus(
						definition, transaction, true, newSynchronization, debugEnabled, suspendedResources);
				doBegin(transaction, definition);
				prepareSynchronization(status, definition);
				return status;
			}
			catch (RuntimeException ex) {
				resume(null, suspendedResources);
				throw ex;
			}
			catch (Error err) {
				resume(null, suspendedResources);
				throw err;
			}
		}
		else {
			// Create "empty" transaction: no actual transaction, but potentially synchronization.
			if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT && logger.isWarnEnabled()) {
				logger.warn("Custom isolation level specified but no actual transaction initiated; " +
						"isolation level will effectively be ignored: " + definition);
			}
			boolean newSynchronization = (getTransactionSynchronization() == SYNCHRONIZATION_ALWAYS);
			return prepareTransactionStatus(definition, null, true, newSynchronization, debugEnabled, null);
		}
	}

如果transaction存在，则return handleExistingTransaction(definition, transaction, debugEnabled);
不存在，则新创建，如果新创建则newSynchronization为true