解决rabbitmq无限循环异常问题亲测 Caused by: org.springframework.amqp.AmqpException: No method found for class [B

springboot项目: 2.2.2版本

rabbitmq 踩坑: 后台无限循环抛出以下异常

Caused by: org.springframework.amqp.AmqpException: No method found for class [B

解决办法:
主要是mq的config类配置问题,第二个是实体序列化问题

config配置

import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
import org.springframework.amqp.support.converter.MessageConverter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


//@Component    //网上有人说去掉这个注解,经试验,无效
@Configuration  //这个注解跟上面那个差不多,但是会比上面那个优先加载
//@EnableRabbit //看见有些会添加这个注解,注释掉也没有什么影响
public class RabbitMQConfig {

    @Bean
    public RabbitTemplate rabbitTemplate(ConnectionFactory factory){
        RabbitTemplate rabbitTemplate = new RabbitTemplate();
        rabbitTemplate.setConnectionFactory(factory);
        //解决: Caused by: org.springframework.amqp.AmqpException: No method found for class [B 异常
        //消息转换器,消息转化为json, setMessageConverter(MessageConverter ),这个方法就是这次异常的解决方案,创建一个Jackson2JsonMessageConverter对象放进去
        rabbitTemplate.setMessageConverter(new Jackson2JsonMessageConverter());
        return rabbitTemplate;
    }

    @Bean
    public SimpleRabbitListenerContainerFactory simpleRabbitListenerContainerFactory(ConnectionFactory factory){
        SimpleRabbitListenerContainerFactory srlcf = new SimpleRabbitListenerContainerFactory();
        srlcf.setConnectionFactory(factory);
        //当消息有异常内容时（例如类型不匹配），将不再重新放入队列，直接丢弃
        srlcf.setDefaultRequeueRejected(false);

        //设置消息转为json
        Jackson2JsonMessageConverter j2jmc = new Jackson2JsonMessageConverter();
        srlcf.setMessageConverter(j2jmc);
        return srlcf;
    }

    //发送消息时如不配置序列化方法则按照java默认序列化机制，则会造成发送编码不符合
    @Bean
    public MessageConverter messageConverter(){
        Jackson2JsonMessageConverter j2jmc = new Jackson2JsonMessageConverter();
        return j2jmc;
    }

}

还有其它版本说:

1. 监听mq的时候以 byte 数组接收,然后再转化为 json, 这个方案确实可以, 但是每次都是这样弄不太友好,而且转化为json之后还要根据消息的类型强转为实体,容易出错

2.实体类实现序列化接口即可(这个确实是造成这个异常是原因之一,但不是最终解决方案,一般都是要实现序列化接口的,这个解决了问题的前提是config配置类已经配置好了的)

[email protected]说是方法级别注解,不能放在类上(纯属扯淡,最基本的注解使用都不懂,就好像@RequestMapping注解一样的道理)

还有其它方案不再一一解述

附:
实体类:

public class Order implements Serializable {
	//发送的实体需要序列化
    private static final long serialVersionUID = 1L;
    private String id;
    private String name;
    private String status;

	//get,set方法不多说,都懂
}

底层发送基础类:

@Component
public class MsgSender {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    //@Autowired
    //private AmqpTemplate amqpTemplate;

    public boolean send(String exchange,String routingKey,Object object){
        try {
            rabbitTemplate.convertAndSend(exchange,routingKey,object);
        } catch (AmqpException e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

}

发送类:

    //Direct交换器模式,发布订阅
    @GetMapping("/send/{msg}")
    public Object send(@PathVariable("msg") String msg){
        Order order = new Order();
        order.setId(UUID.randomUUID().toString());
        order.setName("华为手机");
        order.setStatus("1");
        boolean send = msgSender.send(exchange, routingKey, order);
        if(send){
            return msg+order;
        }
        return "500,发送失败";
    }

监听类

@Component
@RabbitListener(bindings = {
        @QueueBinding(
                value = @Queue(value = "myque",durable = "true"),
                exchange = @Exchange(value = "myexchange",type = ExchangeTypes.DIRECT,ignoreDeclarationExceptions = "true",durable = "true"),
                key = "mykey"
        )
})
public class DirectListen {
    @RabbitHandler
    public void testConsumer(Order order){
        /*String result = null;
        try {
            result = new String(res, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }*/
        System.out.println("I am consumer,that is msg:"+order);
    }


}

监听结果:

I am consumer,that is msg:Order{id='ae1bbc15-49ef-4c3b-9c96-cbcc4b944f98', name='华为手机', status='1'}

详细异常信息:

2020-06-14 12:11:02.918  WARN 9408 --- [ntContainer#0-1] o.s.a.s.c.Jackson2JsonMessageConverter   : Could not convert incoming message with content-type [application/x-java-serialized-object], 'json' keyword missing.
2020-06-14 12:11:02.918  WARN 9408 --- [ntContainer#0-1] s.a.r.l.ConditionalRejectingErrorHandler : Execution of Rabbit message listener failed.

org.springframework.amqp.rabbit.support.ListenerExecutionFailedException: Listener method 'no match' threw exception
	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:219) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandlerAndProcessResult(MessagingMessageListenerAdapter.java:143) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:132) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1569) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1488) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1476) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:1467) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1411) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:958) [spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:908) [spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1600(SimpleMessageListenerContainer.java:81) [spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.mainLoop(SimpleMessageListenerContainer.java:1279) [spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1185) [spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at java.lang.Thread.run(Thread.java:745) [na:1.8.0_102]
Caused by: org.springframework.amqp.AmqpException: No method found for class [B
	at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.getHandlerForPayload(DelegatingInvocableHandler.java:149) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.invoke(DelegatingInvocableHandler.java:129) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.invoke(HandlerAdapter.java:61) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:211) ~[spring-rabbit-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	... 13 common frames omitted