如何通过 spring 集成从 RabbitMQ 获取 header

Question

为了使用 delayed-exchange，我使用这种方法通过 "int:gateway" 消息发送到 RabbitMq：

void send(@Payload Notification request, @Header(MessageProperties.X_DELAY) Integer delay, @Header("routingKey") String routingKey);

我可以在 RabbitMQ 中看到 headers 正确显示： x-delay: -60000

但是，当我从 RabbitMQ 收到这条消息时，我如何才能得到这个 header？

到目前为止，我收到了我之前作为 Json 发送的 object，但是如果我尝试获取 header，我会收到异常。

发送中：

integration.xml 文件:

<!-- Producing service -->
    <int:gateway id="gateway" default-request-channel="producingChannel" service-interface="Gateway"/>
    <!-- Producing service -->


<!-- Service => RabbitMQ (Producing) -->
    <int:chain input-channel="producingChannel">
        <int:object-to-json-transformer/>
        <int-amqp:outbound-channel-adapter exchange-name="${queuing.notifications-exchange}" routing-key-expression="headers.routingKey" mapped-request-headers="*"/>
    </int:chain>
    <!-- Service => RabbitMQ (Producing) -->

java 文件中的网关：

void send(@Payload Notification request, @Header(MessageProperties.X_DELAY) Integer delay, @Header("routingKey") String routingKey);

接收：

integration.xml 文件:

<!-- RabbitMQ => Service (Consuming) -->
    <int-amqp:inbound-channel-adapter channel="consumingChannel" queue-names="${queuing.operator.queue}" concurrent-consumers="${queuing.concurrent-consumers}" prefetch-count="${queuing.prefetch-count}" mapped-request-headers="*" error-channel="errorChannel" />
    <!-- RabbitMQ => Service (Consuming) -->


<!-- Routing -->
<int:chain input-channel="consumingChannel">
    <int:json-to-object-transformer type="Notification"/>
    <int:service-activator ref="workingService" method="processNotificationFromQueue"/>
</int:chain>
<!-- Routing -->

java 文件中的 WorkingService：

public void processNotificationFromQueue(Notification notification,
            @Header(MessageProperties.X_DELAY) Integer delay) { ...
 }

这里抛出异常：

Caused by: java.lang.IllegalArgumentException: required header not available: x-delay

Answer 1

您必须改用 AmqpHeaders.RECEIVED_DELAY。

由于您使用正确的 mapped-request-headers="*" 默认 DefaultAmqpHeaderMapper 映射正确 :

Integer receivedDelay = amqpMessageProperties.getReceivedDelay();
if (receivedDelay != null) {
    headers.put(AmqpHeaders.RECEIVED_DELAY, receivedDelay);
}

如何通过 spring 集成从 RabbitMQ 获取 header

How to get header from RabbitMQ with spring integration

spring-integration

spring-rabbit

rabbitmq-exchange