Spring通过注解获取所有被注解标注的Beans

Spring提供的方法：Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType) throws BeansException;

1，作用：Find all beans whose Class has the supplied Annotation type.

找到所有拥有annotationType注解的bean；

2，参数：annotationType - the type of annotation to look for：

需要获得的bean的注解类型。

3，Returns: a Map with the matching beans, containing the bean names as keys and the corresponding bean instances as values。

返回一个被注解表示的bean的Map对象，bean的names作为key，与name对应的实例做为值。

4. Throws: BeansException - if a bean could not be created、

如果bean不能被创建，抛出beanException！

遍历所有bean：

@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
Map<String, Object> beans
= event.getApplicationContext().getBeansWithAnnotation(MsgTypeHandler.class);
MessageServiceContext
messageServiceContext =
event.getApplicationContext().getBean(MessageServiceContext.class);
beans.forEach((name, bean)
-> {
MsgTypeHandler typeHandler =
bean.getClass().getAnnotation(MsgTypeHandler.class);
messageServiceContext.putMessageService(typeHandler.value().code,
(MessageService) bean);
}

);
}
未完待续~