public static void main(String[] args) {
    // 今天 
    LocalDateTime now = LocalDateTime.now();
    // 昨天
    LocalDateTime yesterday = now.minusDays(1);
    // 明天
    LocalDateTime tomorrow = now.plusDays(1);
    

    // 昨天在今天之前
    System.out.println(yesterday.isBefore(now));
    // 明天在今天之后
    System.out.println(tomorrow.isAfter(now));
}