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

痛定思痛。 2022-04-25 07:02 177阅读 0赞

在用Springboot 中使用rabbitMq的过程中，项目启动后循环报错：

Caused by: org.springframework.amqp.AmqpException: No method found for class [B
    	at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.getHandlerForPayload(DelegatingInvocableHandler.java:147) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.getMethodNameFor(DelegatingInvocableHandler.java:250) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.getMethodAsString(HandlerAdapter.java:70) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:190) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:120) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1414) ~[spring-rabbit-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    	... 8 more

然后很无语，以前好好着，怎么突然爆这个错了。但出错了还得解决，通过查看文档，发现这段：

There are two conversions in the @RabbitListener pipeline.
    The first converts from a Spring AMQP Message to a spring-messaging Message.
    There is currently no way to change the first converter from SimpleMessageConverter which handles String, Serializable and passes everything else as byte[].
    The second converter converts the message payload to the method parameter type (if necessary).
    With method-level @RabbitListeners there is a tight binding between the handler and the method.
    With class-level @RabbitListener s, the message payload from the first conversion is used to select which method to invoke. Only then, is the argument conversion attempted.
    This mechanism works fine with Java Serializable objects since the payload has already been converted before the method is selected.
    However, with JSON, the first conversion returns a byte[] and hence we find no matching @RabbitHandler.
    We need a mechanism such that the first converter is settable so that the payload is converted early enough in the pipeline to select the appropriate handler method.
    A ContentTypeDelegatingMessageConverter is probably most appropriate.
    And, as stated in AMQP-574, we need to clearly document the conversion needs for a @RabbitListener, especially when using JSON or a custom conversion.

定睛一看原来是@RabbitListener 有2个版本。解决办法如下：

@Bean
        public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
            RabbitTemplate template = new RabbitTemplate(connectionFactory);
            template.setMessageConverter(new Jackson2JsonMessageConverter());
            return template;
        }
    
        @Bean
        public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) {
            SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
            factory.setConnectionFactory(connectionFactory);
            factory.setMessageConverter(new Jackson2JsonMessageConverter());
            return factory;
        }

然后在接收端和发送端加上：containerFactory="rabbitListenerContainerFactory"  问题解决：最后完整代码：

import java.util.HashMap;
    import java.util.Map;
    import org.springframework.amqp.rabbit.connection.ConnectionFactory;
    import org.springframework.amqp.core.Binding;
    import org.springframework.amqp.core.BindingBuilder;
    import org.springframework.amqp.core.Queue;
    import org.springframework.amqp.core.TopicExchange;
    import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory;
    import org.springframework.amqp.rabbit.core.RabbitTemplate;
    import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    @Configuration
    public class TopicRabbitConfig {
        @Bean
        public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
            RabbitTemplate template = new RabbitTemplate(connectionFactory);
            template.setMessageConverter(new Jackson2JsonMessageConverter());
            return template;
        }
    
        @Bean
        public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) {
            SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
            factory.setConnectionFactory(connectionFactory);
            factory.setMessageConverter(new Jackson2JsonMessageConverter());
            return factory;
        }
        @Bean
        public Queue mileCalculateMessage() {
            Map<String, Object> args = new HashMap<String, Object>();
            return new Queue("shift_generator_queue", false, false, false,args); //队列过期
        }
     
        @Bean
        TopicExchange exchange() {
            return new TopicExchange("amq.topic");
        }
        @Bean
        Binding bindingExchangemileCalculateMessage(Queue mileCalculateMessage, TopicExchange exchange) {
            return BindingBuilder.bind(mileCalculateMessage).to(exchange).with("shift_generator_queue");
        }
    }

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
    import org.springframework.amqp.rabbit.annotation.RabbitListener;
    import org.springframework.stereotype.Component;
    
    @Component
    public class TopicReceiver {
        @RabbitListener(queues = "shift_generator_queue",containerFactory="rabbitListenerContainerFactory")
        public void process(byte [] message) {
    		System.out.println(new String(message));
        }
    }

最后附张完整的截图：