org.springframework.beans.factory包下有一个接口是InitializingBean 只有一个方法：

/**
  * Invoked by a BeanFactory after it has set all bean properties supplied
  * (and satisfied BeanFactoryAware and ApplicationContextAware).
  * <p>This method allows the bean instance to perform initialization only
  * possible when all bean properties have been set and to throw an
  * exception in the event of misconfiguration.
  * @throws Exception in the event of misconfiguration (such
  * as failure to set an essential property) or if initialization fails.
  */
 void afterPropertiesSet() throws Exception;

这个方法将在所有的属性被初始化后调用。

但是会在init前调用。

但是主要的是如果是延迟加载的话，则马上执行。

所以可以在类上加上注解：

import org.springframework.context.annotation.Lazy;

@Lazy(false)

这样spring容器初始化的时候afterPropertiesSet就会被调用。

只需要实现InitializingBean接口就行。