如何在rabbbitmq中配置队列的使用者以侦听多个数据类型的消息？

Question

我正在尝试使用Rabbitmq的队列来生成和使用一种以上数据类型的消息。例如。我能够使用杰克逊序列化程序和一个String对象在队列中推送一个雇员对象（json格式），但是当我尝试使用该消息时，我得到了解析错误。 （最终，我可以推送任何东西，但是当我尝试消耗时，我却不能）。

```
**Producer code**

package com.poc.springbootrabbitmq.service;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import com.poc.springbootrabbitmq.model.Employee;

@Service
public class RabbitMQSender 
{
    @Autowired
    private AmqpTemplate amqpTemplate;

    @Value("${exchangeName}")
    private String exchange;

    public void send(Employee company) 
    {
        amqpTemplate.convertAndSend(exchange,"error", company);
        amqpTemplate.convertAndSend(exchange,"error", "some String");
    }

}


**Consumer Code**



package com.rabbitmq.consumer.service;

import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

import com.rabbitmq.consumer.model.Employee;

@Component
public class RabbitMQConsumer 
{
    @RabbitListener(queues = "${queueName}")
    public void recievedMessage(Employee employee) {
        System.out.println("Recieved Message From Queue " + employee);
    }

    @RabbitListener(queues = "${queueName}")
    public void recievedMessage1(String string) {
        System.out.println("Recieved Message From Queue " + string);
    }

}


**Employee.java**

package com.rabbitmq.consumer.model;

public class Employee {

    private String empName;
    private String empId;

    public String getEmpName() {
        return empName;
    }

    public void setEmpName(String empName) {
        this.empName = empName;
    }

    public String getEmpId() {
        return empId;
    }

    public void setEmpId(String empId) {
        this.empId = empId;
    }

    @Override
    public String toString() {
        return "Employee [empName=" + empName + ", empId=" + empId + "]";
    }

}

**My defined beans/configurations**

package com.rabbitmq.consumer.configuration;

import org.springframework.amqp.rabbit.annotation.EnableRabbit;
import org.springframework.amqp.rabbit.annotation.RabbitListenerConfigurer;
import org.springframework.amqp.rabbit.listener.RabbitListenerEndpointRegistrar;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.converter.MappingJackson2MessageConverter;
import org.springframework.messaging.handler.annotation.support.DefaultMessageHandlerMethodFactory;

@EnableRabbit
@Configuration
public class ConsumerConfiguration implements RabbitListenerConfigurer
{

    @Bean
    public MappingJackson2MessageConverter jackson2Converter() {
        MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
        return converter;
    }

    @Bean
    public DefaultMessageHandlerMethodFactory myHandlerMethodFactory() 
    {
        DefaultMessageHandlerMethodFactory factory = new DefaultMessageHandlerMethodFactory();
        factory.setMessageConverter(jackson2Converter());
        return factory;
    }

    @Override
    public void configureRabbitListeners(RabbitListenerEndpointRegistrar registrar) 
    {
        registrar.setMessageHandlerMethodFactory(myHandlerMethodFactory());
    }

}

**ErrorLog I'm getting**

2019-04-21 20:27:31.585  WARN 5436 --- [ntContainer#0-1] s.a.r.l.ConditionalRejectingErrorHandler : Execution of Rabbit message listener failed.

org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener method could not be invoked with the incoming message
Endpoint handler details:
Method [public void com.rabbitmq.consumer.service.RabbitMQConsumer.recievedMessage3(com.rabbitmq.consumer.model.Employee)]
Bean [com.rabbitmq.consumer.service.RabbitMQConsumer@1457fde]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:193) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:127) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1552) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1478) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1466) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:1461) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1410) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:870) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:854) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1600(SimpleMessageListenerContainer.java:78) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.mainLoop(SimpleMessageListenerContainer.java:1137) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1043) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]
Caused by: org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:234) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:181) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.annotation.support.PayloadArgumentResolver.resolveArgument(PayloadArgumentResolver.java:137) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:117) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:147) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:116) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.invoke(HandlerAdapter.java:49) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:190) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 12 common frames omitted
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1343) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1032) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1373) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3121) ~[jackson-databind-2.9.8.jar:2.9.8]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:221) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 19 common frames omitted

2019-04-21 20:27:31.680  WARN 5436 --- [ntContainer#0-1] ingErrorHandler$DefaultExceptionStrategy : Fatal message conversion error; message rejected; it will be dropped or routed to a dead letter exchange, if so configured: (Body:'"some String"' MessageProperties [headers={__TypeId__=java.lang.String}, contentType=application/json, contentEncoding=UTF-8, contentLength=0, receivedDeliveryMode=PERSISTENT, priority=0, redelivered=false, receivedExchange=sampleTopicExchange, receivedRoutingKey=x.y.error, deliveryTag=6, consumerTag=amq.ctag-ZlMlqxVR24vqzgAGGWE4-Q, consumerQueue=sampleTopicQueue1])
2019-04-21 20:27:31.728 ERROR 5436 --- [ntContainer#0-1] o.s.a.r.l.SimpleMessageListenerContainer : Execution of Rabbit message listener failed, and the error handler threw an exception

org.springframework.amqp.AmqpRejectAndDontRequeueException: Error Handler converted exception to fatal
    at org.springframework.amqp.rabbit.listener.ConditionalRejectingErrorHandler.handleError(ConditionalRejectingErrorHandler.java:105) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeErrorHandler(AbstractMessageListenerContainer.java:1378) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.handleListenerException(AbstractMessageListenerContainer.java:1631) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1424) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:870) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:854) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1600(SimpleMessageListenerContainer.java:78) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.mainLoop(SimpleMessageListenerContainer.java:1137) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1043) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]
Caused by: org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener method could not be invoked with the incoming message
Endpoint handler details:
Method [public void com.rabbitmq.consumer.service.RabbitMQConsumer.recievedMessage3(com.rabbitmq.consumer.model.Employee)]
Bean [com.rabbitmq.consumer.service.RabbitMQConsumer@1457fde]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:193) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:127) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1552) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1478) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1466) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:1461) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1410) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 6 common frames omitted
Caused by: org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:234) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:181) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.annotation.support.PayloadArgumentResolver.resolveArgument(PayloadArgumentResolver.java:137) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:117) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:147) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:116) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.invoke(HandlerAdapter.java:49) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:190) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 12 common frames omitted
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.rabbitmq.consumer.model.Employee` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('some String')
 at [Source: (byte[])""some String""; line: 1, column: 1]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1343) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1032) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1373) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013) ~[jackson-databind-2.9.8.jar:2.9.8]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3121) ~[jackson-databind-2.9.8.jar:2.9.8]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:221) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 19 common frames omitted
```

Answer 1

@Component
public class RabbitMQConsumer 
{
    @RabbitListener(queues = "${queueName}")
    public void recievedMessage(Employee employee) {
        System.out.println("Recieved Message From Queue " + employee);
    }

    @RabbitListener(queues = "${queueName}")
    public void recievedMessage1(String string) {
        System.out.println("Recieved Message From Queue " + string);
    }

}

使用该配置，您将获得2个侦听器容器，它们将争夺所有消息，您需要在类级别使用@RabbitListener，在方法级别需要@RabbitHandler。

但是，由于有效负载首先需要反序列化，因此框架存在陷阱22，因此框架可以确定要调用的方法。我们无法从method参数推断类型，您必须在容器工厂中使用Jackson2JsonMessageConverter，以便它可以首先根据消息标题中的信息进行转换。

请参见the documentation。