code: public static boolean sleep(Number millis) {
  		if (millis == null) {
  			return true;
  		}
  
  		try {
  			Thread.sleep(millis.longValue());
  		} catch (InterruptedException e) {
  			return false;
  		}
  		return true;
  	}
docs: 挂起当前线程
  
  @param millis 挂起的毫秒数
  @return 被中断返回false，否则true