源码解析: Spring RabbitMQ消费者_rabbitmqbeanprocessor

从Spring RabbitMQ消费者启动，到接收消息和执行消费逻辑，一步步了解其实现。

目录

• • 1. 消费者如何启动过程
  • • 1.1 启动配置类
    • 1.2 创建消费者核心逻辑
    • 1.3 PS: BeanPostPorcessor如何被Spring处理？
  • 2. RabbitMQ消息如何被消费
  • • 2.1 SimpleMessageListenerContainer
    • 2.2 BlockingQueueConsumer

1. 消费者如何启动过程

1.1 启动配置类

创建RabbitListenerAnnotationBeanPostProcessor

@Configuration
public class RabbitBootstrapConfiguration {
   

	@Bean(name = RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME)
	@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
	public RabbitListenerAnnotationBeanPostProcessor rabbitListenerAnnotationProcessor() {
   
		return new RabbitListenerAnnotationBeanPostProcessor();
	}
.....
}
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1.2 创建消费者核心逻辑

核心逻辑在RabbitListenerAnnotationBeanPostProcessor，在Spring Bean初始化过程中执行。
对于每个消息监听都会创建对应的MessageListenerContainer（默认实现为SimpleMessageListenerContainer）

// 通过BeanPostProcessor在Bean创建后，创建消息监听器
public class RabbitListenerAnnotationBeanPostProcessor
		implements BeanPostProcessor, Ordered, BeanFactoryAware, BeanClassLoaderAware, EnvironmentAware,
			SmartInitializingSingleton {
   
  ......
      @Override
      public Object postProcessAfterInitialization(final Object bean, final String beanName) throws BeansException {
   
      Class<?> targetClass = AopUtils.getTargetClass(bean);
      // 通过反射获取@RabbitListener修饰的方法
      final TypeMetadata metadata = this.typeCache.computeIfAbsent(targetClass, this::buildMetadata);
      for (ListenerMethod lm : metadata.listenerMethods) {
   
          for (RabbitListener rabbitListener : lm.annotations) {
   
              // 创建MethodRabbitListenerEndpoint，并注册到RabbitListenerEndpointRegistrar
              processAmqpListener(rabbitListener, lm.method, bean, beanName);
          }
      }
      if (metadata.handlerMethods.length > 0) {
   
          processMultiMethodListeners(metadata.classAnnotations, metadata.handlerMethods, bean, beanName);
      }
      return bean;
  }

	protected void processAmqpListener(
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