RocketMQ RocketMQMessageListener注解自动配置源码

• org.apache.rocketmq.spring.autoconfigure.ListenerContainerConfiguration

// 根据注解查找所有bean
@Override
public void afterSingletonsInstantiated() {
    Map<String, Object> beans = this.applicationContext.getBeansWithAnnotation(RocketMQMessageListener.class)
        .entrySet().stream().filter(entry -> !ScopedProxyUtils.isScopedTarget(entry.getKey()))
        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));

    beans.forEach(this::registerContainer);
}
// 根据Listener注册ListenerContainer
private void registerContainer(String beanName, Object bean) {
    Class<?> clazz = AopProxyUtils.ultimateTargetClass(bean);
...
    RocketMQMessageListener annotation = clazz.getAnnotation(RocketMQMessageListener.class);
	// 获取消费者组、主题
    String consumerGroup = this.environment.resolvePlaceholders(annotation.consumerGroup());
    String topic = this.environment.resolvePlaceholders(annotation.topic());
	// 判断应用配置中对应组和主题是否激活
    boolean listenerEnabled =
        (boolean) rocketMQProperties.getConsumer().getListeners().getOrDefault(consumerGroup, Collections.EMPTY_MAP)
            .getOrDefault(topic, true);

    if (!listenerEnabled) {
        log.debug(
            "Consumer Listener (group:{},topic:{}) is not enabled by configuration, will ignore initialization.",
            consumerGroup, topic);
        return;
    }
    // 校验消息模式和消费模式是否冲突（广播模式不能顺序消费）
    validate(annotation);

    String containerBeanName = String.format("%s_%s", DefaultRocketMQListenerContainer.class.getName(),
        counter.incrementAndGet());
    GenericApplicationContext genericApplicationContext = (GenericApplicationContext) applicationContext;
	// 创建注册RocketMQListenerContainerBean
    genericApplicationContext.registerBean(containerBeanName, DefaultRocketMQListenerContainer.class,
        () -> createRocketMQListenerContainer(containerBeanName, bean, annotation));
    // 启动ListenerContainer
    DefaultRocketMQListenerContainer container = genericApplicationContext.getBean(containerBeanName,
        DefaultRocketMQListenerContainer.class);
    if (!container.isRunning()) {
        try {
            container.start();
        } catch (Exception e) {
            log.error("Started container failed. {}", container, e);
            throw new RuntimeException(e);
        }
    }

    log.info("Register the listener to container, listenerBeanName:{}, containerBeanName:{}", beanName, containerBeanName);
}
// 创建ListenerContainer
private DefaultRocketMQListenerContainer createRocketMQListenerContainer(String name, Object bean,
    RocketMQMessageListener annotation) {
    DefaultRocketMQListenerContainer container = new DefaultRocketMQListenerContainer();

    container.setRocketMQMessageListener(annotation);

    String nameServer = environment.resolvePlaceholders(annotation.nameServer());
    nameServer = StringUtils.isEmpty(nameServer) ? rocketMQProperties.getNameServer() : nameServer;
    String accessChannel = environment.resolvePlaceholders(annotation.accessChannel());
    container.setNameServer(nameServer);
    if (!StringUtils.isEmpty(accessChannel)) {
        container.setAccessChannel(AccessChannel.valueOf(accessChannel));
    }
    container.setTopic(environment.resolvePlaceholders(annotation.topic()));
    String tags = environment.resolvePlaceholders(annotation.selectorExpression());
    if (!StringUtils.isEmpty(tags)) {
        container.setSelectorExpression(tags);
    }
    container.setConsumerGroup(environment.resolvePlaceholders(annotation.consumerGroup()));
    if (RocketMQListener.class.isAssignableFrom(bean.getClass())) {
        container.setRocketMQListener((RocketMQListener) bean);
    } else if (RocketMQReplyListener.class.isAssignableFrom(bean.getClass())) {
        container.setRocketMQReplyListener((RocketMQReplyListener) bean);
    }
    container.setMessageConverter(rocketMQMessageConverter.getMessageConverter());
    container.setName(name);

    return container;
}