LocalDateTime.now()时间处理jdk1.8日期便捷处理类java.time.LocalDateTime;

        //获取当前时间
        System.out.println(LocalDateTime.now());
        //获取当前时间时分秒
        System.out.println(LocalDateTime.now().toLocalTime());
        //获取当前时间年月日
        System.out.println(LocalDateTime.now().toLocalDate());
        //获取当前时间20天之前
        System.out.println(LocalDateTime.now().minusDays(20));
        //获取当前时间20天之后
        System.out.println(LocalDateTime.now().plusDays(20));
        //获取当前时间60天之前
        System.out.println(LocalDateTime.now().minusDays(60));
        //所有minus开头都是之前    plus开头都是之后
        
        //比较大小
        System.out.println(LocalDateTime.now().compareTo(LocalDateTime.now().plusDays(2)));

        //实例化方式   以及比较大小
        Duration between = Duration.between(LocalDateTime.of(1993,3,14,0,0), LocalDateTime.now());
        Duration between2 = Duration.between(LocalDateTime.of(1993,3,14,0,0), LocalDateTime.now());
        System.out.println(between.toDays());
        System.out.println(between2.toDays());