java – 配置Spring Integration聚合器以组合RabbitMq扇出交换的响应

我试图使用Spring Integration配置以下内容：

>向频道发送消息.
>将此消息发布到与n个消费者的兔子扇出(pub / sub)交换.
>每个消费者都提供响应消息.
>让Spring Integration在将它们返回到原始客户端之前聚合这些响应.

到目前为止,我有一些问题……

>我正在使用发布 – 订阅 – 通道来设置apply-sequence =“true”属性,以便correlationId,sequenceSize& sequenceNumber属性已设置. DefaultAmqpHeaderMapper抛弃了这些属性. DEBUG headerName = [correlationId]将不会被映射
>即使在扇出交换中注册了2个队列,sequenceSize属性也只被设置为1.据推测,这意味着消息将过早地从聚合器中释放.我希望这是因为我滥用发布 – 订阅 – 频道才能使用apply-sequence =“true”,而且正确地说只有一个订户,即int-amqp：outbound-gateway.

我的出站Spring配置如下：

<int:publish-subscribe-channel id="output" apply-sequence="true"/>

<int:channel id="reply">
    <int:interceptors>
        <int:wire-tap channel="logger"/>
    </int:interceptors>
</int:channel>

<int:aggregator input-channel="reply" method="combine">
    <bean class="example.SimpleAggregator"/>
</int:aggregator>

<int:logging-channel-adapter id="logger" level="INFO"/>

<int:gateway id="senderGateway" service-interface="example.SenderGateway" default-request-channel="output" default-reply-channel="reply"/>

<int-amqp:outbound-gateway request-channel="output"
                                   amqp-template="amqpTemplate" exchange-name="fanout-exchange"
                                   reply-channel="reply"/>

我的rabbitMQ配置如下：

<rabbit:connection-factory id="connectionFactory" />

<rabbit:template id="amqpTemplate" connection-factory="connectionFactory" reply-timeout="-1" />

<rabbit:admin connection-factory="connectionFactory" />

<rabbit:queue name="a-queue"/>
<rabbit:queue name="b-queue"/>

<rabbit:fanout-exchange name="fanout-exchange">
    <rabbit:bindings>
        <rabbit:binding queue="a-queue" />
        <rabbit:binding queue="b-queue" />
    </rabbit:bindings>
</rabbit:fanout-exchange>

消费者看起来像这样：

<int:channel id="input"/>

<int-amqp:inbound-gateway request-channel="input" queue-names="a-queue" connection-factory="connectionFactory" concurrent-consumers="1"/>

<bean id="listenerService" class="example.ListenerService"/>

<int:service-activator input-channel="input" ref="listenerService" method="receiveMessage"/>

任何建议都会很棒,我怀疑我的某个地方有错误的结尾……

基于Gary的评论新的出站弹簧配置：

<int:channel id="output"/>

<int:header-enricher input-channel="output" output-channel="output">
    <int:correlation-id expression="headers['id']" />
</int:header-enricher>

<int:gateway id="senderGateway" service-interface="example.SenderGateway" default-request-channel="output" default-reply-timeout="5000" default-reply-channel="reply" />

<int-amqp:outbound-gateway request-channel="output"
                                   amqp-template="amqpTemplate" exchange-name="fanout-exchange"
                                   reply-channel="reply"
                                   mapped-reply-headers="amqp*,correlationId" mapped-request-headers="amqp*,correlationId"/>

<int:channel id="reply"/>

<int:aggregator input-channel="reply" output-channel="reply" method="combine" release-strategy-expression="size() == 2">
    <bean class="example.SimpleAggregator"/>
</int:aggregator>

解决方法:

问题是S.I.不知道扇出交换的拓扑结构.

最简单的方法是使用自定义发布策略

release-strategy-expression="size() == 2"

在聚合器上(假设扇出为2).所以,你不需要序列大小;你可以避免使用标题扩充器“滥用”发布/订阅者频道…

    <int:header-enricher input-channel="foo" output-channel="bar">
        <int:correlation-id expression="T(java.util.UUID).randomUUID().toString()" />
    </int:header-enricher>

您可以使用消息ID避免创建新的UUID,消息ID已经是唯一的…

<int:correlation-id expression="headers['id']" />

最后,您可以通过添加将correlationId标头传递给AMQP

mapped-request-headers="correlationId"

到你的amqp端点.

标签：java,rabbitmq,spring-integration,spring-amqp
来源： https://codeday.me/bug/20190704/1373378.html