今天專案中出現一個詭異的異常：

org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener threw exception
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.wrapToListenerExecutionFailedExceptionIfNeeded(AbstractMessageListenerContainer.java:915)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:825)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:745)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:97)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:189)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1276)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:726)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:1219)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:1189)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1500(SimpleMessageListenerContainer.java:97)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1421)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.amqp.rabbit.listener.adapter.ReplyFailureException: Failed to send reply with payload 'OK'
	at org.springframework.amqp.rabbit.listener.adapter.AbstractAdaptableMessageListener.handleResult(AbstractAdaptableMessageListener.java:285)
	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:108)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:822)
	... 10 common frames omitted
Caused by: org.springframework.amqp.AmqpException: Cannot determine ReplyTo message property value: Request message does not contain reply-to property, and no default response Exchange was set.
	at org.springframework.amqp.rabbit.listener.adapter.AbstractAdaptableMessageListener.getReplyToAddress(AbstractAdaptableMessageListener.java:373)
	at org.springframework.amqp.rabbit.listener.adapter.AbstractAdaptableMessageListener.handleResult(AbstractAdaptableMessageListener.java:281)
	... 12 common frames omitted
 

專案使用Spring Boot、Gradle、Groovy、RabbitMQ，出現異常的程式碼如下：

@RabbitListener(queues = Constants.POST_PUSH_QUEUE_THIRD_REDIS)
    @RabbitHandler
    def processThirdRedis(Article article) throws Exception {
        def key = REDIS_ARTICLE_PREFIX + article.id
        redisService.set(key, JsonUtil.toJson(article))
    }
 

終於在這裡找到了答案。

原來，使用

@RabbitListener(queues = Constants.POST_PUSH_QUEUE_THIRD_REDIS)
    @RabbitHandler

protected void handleResult(Object resultArg, Message request, Channel channel, Object source) throws Exception {
		if (channel != null) {
			if (this.logger.isDebugEnabled()) {
				this.logger.debug("Listener method returned result [" + resultArg
						+ "] - generating response message for it");
			}
			try {
				Object result = resultArg instanceof ResultHolder ? ((ResultHolder) resultArg).result : resultArg;
				Message response = buildMessage(channel, result);
				postProcessResponse(request, response);
				Address replyTo = getReplyToAddress(request, source, resultArg);
				sendResponse(channel, replyTo, response);
			}
			catch (Exception ex) {
				throw new ReplyFailureException("Failed to send reply with payload '" + resultArg + "'", ex);
			}
		}
		else if (this.logger.isWarnEnabled()) {
			this.logger.warn("Listener method returned result [" + resultArg
					+ "]: not generating response message for it because no Rabbit Channel given");
		}
	}
 

protected Address getReplyToAddress(Message request, Object source, Object result) throws Exception {
		Address replyTo = request.getMessageProperties().getReplyToAddress();
		if (replyTo == null) {
			if (this.responseAddress == null && this.responseExchange != null) {
				this.responseAddress = new Address(this.responseExchange, this.responseRoutingKey);
			}
			if (result instanceof ResultHolder) {
				replyTo = evaluateReplyTo(request, source, result, ((ResultHolder) result).sendTo);
			}
			else if (this.responseExpression != null) {
				replyTo = evaluateReplyTo(request, source, result, this.responseExpression);
			}
			else if (this.responseAddress == null) {
				throw new AmqpException(
						"Cannot determine ReplyTo message property value: " +
								"Request message does not contain reply-to property, " +
								"and no default response Exchange was set.");
			}
			else {
				replyTo = this.responseAddress;
			}
		}
		return replyTo;
	}

解決後的程式碼為：

@RabbitListener(queues = Constants.POST_PUSH_QUEUE_THIRD_REDIS)
    @RabbitHandler
    void processThirdRedis(Article article) throws Exception {
        def key = REDIS_ARTICLE_PREFIX + article.id
        redisService.set(key, JsonUtil.toJson(article))
    }