java - 如何忽略 Spring Integration 路由器中的 Channel ResolutionException？

Question

Spring Integration 路由器在 XML 配置中指定如下:

<int:chain id="integrationFrontDoorQueueChain" input-channel="integrationFrontDoorQueueChannel">
    <int:transformer ref="integrationJsonPayloadTransformer" method="transformMessagePayload"/>
    <int:service-activator ref="firstScanInventoryService" method="sendMessage"/>
    <int:router ref="integrationRouterImpl" method="route" default-output-channel="nullChannel"/> 
</int:chain>

在 IntegrationRouterImpl 的 Java 代码中，我们找到了 channel 列表。

@Component("integrationRouterImpl")
public class IntegrationRouterImpl {
    private final IntegrationReferenceDataLoader integrationReferenceDataLoader;

    @Autowired
    public IntegrationRouterImpl(IntegrationReferenceDataLoader integrationReferenceDataLoader) {
         this.integrationReferenceDataLoader = integrationReferenceDataLoader;
    }

    public List<String> route(IntegrationPayload integrationPayload) {
        final List<String> channelList = new ArrayList<String>();
        for (Long productId : integrationPayload.getProductIds()) {
            final Set<String> channels = integrationReferenceDataLoader.findChannelsForProduct(productId, integrationPayload.getAction().name());
            if (channels != null) {
                channelList.addAll(channels);
            }
        }
        return channelList;
    }
}

看起来，如果 channelList 中的第一个 channel 根本没有配置，那么第二个 channel 也不会被调用。有一个异常(exception):

[org.springframework.integration.support.channel.ChannelResolutionException: failed to look up MessageChannel bean with name 'seaActivationChannel'.  

但是，我没有找到捕获此异常并移至下一个 channel 的方法

路由器中离开方法路由后的堆栈流程如下:

2015-12-18 15:06:30,297 [SimpleAsyncTaskExecutor-1] DEBUG org.springframework.integration.handler.LoggingHandler:67 - (inner bean)#8 received message: [Payload=org.springframework.integration.MessagingException: failed to resolve channel name 'seaActivationChannel'][Headers={timestamp=1450469190297, id=60c2f22b-55a0-4512-7d5c-f798ef67c8ca}]
2015-12-18 15:06:30,299 [SimpleAsyncTaskExecutor-1] ERROR org.springframework.integration.handler.LoggingHandler:140 - org.springframework.integration.MessagingException: failed to resolve channel name 'seaActivationChannel'
    at org.springframework.integration.router.AbstractMappingMessageRouter.resolveChannelForName(AbstractMappingMessageRouter.java:168)
    at org.springframework.integration.router.AbstractMappingMessageRouter.addChannelFromString(AbstractMappingMessageRouter.java:197)
    at org.springframework.integration.router.AbstractMappingMessageRouter.addToCollection(AbstractMappingMessageRouter.java:218)

……………

Caused by: org.springframework.integration.support.channel.ChannelResolutionException: failed to look up MessageChannel bean with name 'seaActivationChannel'
    at org.springframework.integration.support.channel.BeanFactoryChannelResolver.resolveChannelName(BeanFactoryChannelResolver.java:102)
    at org.springframework.integration.router.AbstractMappingMessageRouter.resolveChannelForName(AbstractMappingMessageRouter.java:164)
    ... 74 more

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'seaActivationChannel' is defined
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:568)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1102)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:278)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
    at org.springframework.integration.support.channel.BeanFactoryChannelResolver.resolveChannelName(BeanFactoryChannelResolver.java:93)

Answer 1

首先看起来您使用的是 Spring Integration 3.0.x 或更高版本。 ChannelResolutionException已从 Spring Integration 4.0 更改为 DestinationResolutionException 。虽然没关系。

不知道为什么你没见过，但是<router>支持您需要的选项:

   <xsd:attribute name="resolution-required">
            <xsd:annotation>
                <xsd:documentation>
                    Specify whether channel names must always be successfully resolved
                    to existing channel instances.

                    If set to 'true', a MessagingException will be raised in case
                    the channel cannot be resolved. Setting this attribute to 'false',
                    will cause any unresovable channels to be ignored.

                    If not explicitly set, 'resolution-required' will
                    default to 'true'.
                </xsd:documentation>
            </xsd:annotation>
            <xsd:simpleType>
                <xsd:union memberTypes="xsd:boolean xsd:string" />
            </xsd:simpleType>
        </xsd:attribute>
    </xsd:complexType>