code: public static void addShutdownHook(Runnable hook) {
  		Runtime.getRuntime().addShutdownHook((hook instanceof Thread) ? (Thread) hook : new Thread(hook));
  	}
docs: 增加一个JVM关闭后的钩子，用于在JVM关闭时执行某些操作
  
  @param hook 钩子
  @since 4.0.5