java - 如何在 spring boot 应用程序中使用 spring-rabbit 处理 JSON 消息？

Question

这是我的代码片段。

• MQConfiguration 配置类

  @Configuration
  public class MQConfiguration {
      @Bean
      public Receiver receiver() {
          return new Receiver();
      }
  }
  

• Receiver 处理接收消息的类

  @RabbitListener(queues = "testMQ")
  public class Receiver {
  
      @RabbitHandler
      public void receive(Message msg){
          System.out.println(msg.toString());
      }
  }
  

• 这是我发送到 RabbitMQ

  的 JSON 消息

  {
      "id": 1,
      "name": "My Name",
      "description": "This is description about me"
  }
  

但是，当我运行我的应用程序时，我收到了以下错误消息。

2017-02-28 17:16:35.931  WARN 11828 --- [cTaskExecutor-1] s.a.r.l.ConditionalRejectingErrorHandler : Execution of Rabbit message listener failed.

org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener threw exception
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.wrapToListenerExecutionFailedExceptionIfNeeded(AbstractMessageListenerContainer.java:872) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:782) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:702) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:95) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:186) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1227) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:683) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:1181) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:1165) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1500(SimpleMessageListenerContainer.java:95) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1367) [spring-rabbit-1.7.0.RELEASE.jar:na]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_60]
Caused by: org.springframework.amqp.AmqpException: No method found for class [B
    at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.getHandlerForPayload(DelegatingInvocableHandler.java:127) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.getMethodNameFor(DelegatingInvocableHandler.java:224) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.getMethodAsString(HandlerAdapter.java:61) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:140) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:106) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:779) ~[spring-rabbit-1.7.0.RELEASE.jar:na]
    ... 10 common frames omitted

那么如果我只想在receive()方法中打印JSON消息怎么办？我真的很感激任何人都可以阐明这一点。 :)

Answer 1

如果你使用Spring Boot，你只需要配置:

@Bean
public MessageConverter jsonMessageConverter() {
    return new Jackson2JsonMessageConverter();
}

否则你必须配置:

@Bean
public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory() {
    SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
...
    factory.setMessageConverter(new Jackson2JsonMessageConverter());
...
    return factory;
}

http://docs.spring.io/spring-amqp/docs/1.7.0.RELEASE/reference/html/_reference.html#async-annotation-driven