* 可以对spring管理的bean动手术（bean的属性等）
 * To interact with the container’s management of the bean lifecycle, you can
 * implement the Spring InitializingBean and DisposableBean interfaces. The
 * container calls afterPropertiesSet() for the former and destroy() for the
 * latter to allow the bean to perform certain actions upon initialization and
 * destruction of your beans.
 *