如何通過Spring Integration從RabbitMQ獲取標頭

Question

為了使用延遲交換，我使用以下方法通過“ int：gateway”消息將消息發送到RabbitMq：

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

我可以在RabbitMQ中看到標題正確顯示：x-delay：-60000

但是，當我從RabbitMQ收到此消息時如何獲得此標頭？

到目前為止，我收到的是以前作為Json發送的對象，但是如果嘗試獲取標頭，則會收到Exception。

正在發送：

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文件中的網關：

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) { ...
 }

這里拋出異常：

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

Answer 1

您必須改用AmqpHeaders.RECEIVED_DELAY 。

由於您使用正確的mapping mapped-request-headers="*"因此默認的DefaultAmqpHeaderMapper可以正確映射：

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