Spring 集成和 RabbitMQ：接收消息时没有可用的输出通道或回复通道标头

Question

我写了一个带有请求和回复的简单消息流。我必须使用两个独立的队列，所以我声明AmqpOutboundAdapter发送消息，声明Amqp入站Adapter接收回复。

@Bean
@FindADUsers
public AmqpOutboundEndpoint newFindADUsersOutboundAdapter() {
    return Amqp.outboundAdapter(amqpTemplate())
            .routingKeyExpression("headers[" + ADUsersFindConfig.ROUTING_KEY_HEADER + "]")
            .exchangeName(getExchange())
            .headerMapper(amqpHeaderMapper())
            .get();
}

@Bean
public AmqpInboundChannelAdapter newFindADUsersResponseInboundChannelAdapter(
        ADUsersFindResponseConfig config) {
    return Amqp.inboundAdapter(rabbitConnectionFactory(), findADUsersResponseQueue)
            .headerMapper(amqpHeaderMapper())
            .outputChannel(config.newADUsersFindResponseOutputChannel())
            .get();
}

它应该适用于@MessagingGateway：

@MessagingGateway
public interface ADUsersFindService {

     String FIND_AD_USERS_CHANNEL = "adUsersFindChannel";

     String FIND_AD_USERS_REPLY_OUTPUT_CHANNEL = "adUsersFindReplyOutputChannel";

     String FIND_AD_USERS_REPLY_CHANNEL = "adUsersFindReplyChannel";

     String CORRELATION_ID_REQUEST_HEADER = "correlation_id";

     String ROUTING_KEY_HEADER = "replyRoutingKey";

     String OBJECT_TYPE_HEADER = "object.type";

     @Gateway(requestChannel = FIND_AD_USERS_CHANNEL, replyChannel = FIND_AD_USERS_REPLY_CHANNEL)
ADResponse find(ADRequest adRequest, @Header(ROUTING_KEY_HEADER) String routingKey, @Header(OBJECT_TYPE_HEADER) String objectType);
}

ADUsersFindResponseConfig类类似于:

 @Configuration
 @Import(JsonConfig.class)
 public class ADUsersFindResponseConfig {

     @Autowired
     public NullChannel nullChannel;

     @Autowired
     private JsonObjectMapper<?, ?> mapper;

     /**
      * @return The output channel for the flow
      */
     @Bean(name = ADUsersFindService.FIND_AD_USERS_REPLY_OUTPUT_CHANNEL)
     public MessageChannel newADUsersFindResponseOutputChannel() {
         return MessageChannels.direct().get();
     }

     /**
      * @return The output channel for gateway
      */
     @Bean(name = ADUsersFindService.FIND_AD_USERS_REPLY_CHANNEL)
     public MessageChannel newADUsersFindResponseChannel() {
         return MessageChannels.direct().get();
     }

     @Bean
     public IntegrationFlow findADUsersResponseFlow() {
         return IntegrationFlows
                 .from(newADUsersFindResponseOutputChannel())
                 .transform(new JsonToObjectTransformer(ADResponse.class, mapper))
                 .channel(newADUsersFindResponseChannel())
                 .get();
     }
 }

发送消息正常工作，但我在接收消息时遇到问题。我希望收到的消息将被传递到名为FIND_AD_USERS_REPLY_OUTPUT_channel的通道，然后消息将使用findADUsersResponseFlow反序列化为ADResponse对象，下一个ADRespons对象将被传递给网关replyChannel-FIND_ADUSERS_REPLY-channel。最后，“find”方法返回此对象。不幸的是，org.springframework.integration.handler。BridgeHandler收到一条消息，我收到异常：

 org.springframework.messaging.MessagingException: ; nested exception is org.springframework.messaging.core.DestinationResolutionException: no output-channel or replyChannel header available

消息日志如下：

 11:51:35.697 [SimpleAsyncTaskExecutor-1] INFO  New message - GenericMessage [payload={...somepayload...}, headers={correlation_id=7cbd958e-4b09-4e4c-ba8e-5ba574f3309a, replyRoutingKey=findADUsersResponse.ad, amqp_consumerQueue=findADUsersResponseQueue, history=newFindADUsersResponseInboundChannelAdapter,adUsersFindReplyOutputChannel,adUsersFindReplyChannel,infoLog,infoLoggerChain.channel#0,infoLoggerChain.channel#1, id=37a4735d-6983-d1ad-e0a1-b37dc17e48ef, amqp_consumerTag=amq.ctag-8Qs5YEun1jXYRf85Hu1URA, object.type=USER, timestamp=1469094695697}]

所以我很确定该消息已传递给adUsersFindReplyChannel。此外（如果很重要）请求消息和回复消息都将“replyTo”标头设置为 null。我做错了什么？

Answer 1

回复通道标头是一个活动对象，不能通过 AMQP 序列化。

您可以使用出站网关而不是一对适配器，框架将处理头。

如果您出于某种原因必须使用适配器，您需要做两件事：

>

使用标头通道注册表将通道对象转换为在注册表中注册的字符串。

确保标头映射器配置为发送/接收replyChannel标头，并且接收系统在回复中返回标头。