====== SpringFramework Callback ======
  * [[http://www.baeldung.com/running-setup-logic-on-startup-in-spring|Guide To Running Logic on Startup in Spring | Baeldung]]
  * [[http://www.baeldung.com/spring-shutdown-callbacks|Spring Shutdown Callbacks | Baeldung]]
  * [[https://www.dineshonjava.com/bean-lifecycle-and-callbacks/|Spring Bean Life Cycle and Callbacks - Dinesh on Java]]