LocalDateTime java8

public static void main(String[] args) {
DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime startTime = LocalDateTime.now();
LocalDateTime endTime = startTime.plusDays(7);

System.out.println("开始时间：" + startTime.format(df) + "，结束时间：" + endTime.format(df));

LocalDateTime dateTest = LocalDateTime.parse("2018-02-30 12:12:12", df);
System.out.println("时间自动转化：" + dateTest.toString());

int daysNum = Period.between(startTime.toLocalDate(), endTime.toLocalDate()).getDays();
int monthNum = Period.between(startTime.toLocalDate(), endTime.toLocalDate()).getMonths();
System.out.println("相差天数：" + daysNum);
System.out.println("相差月数：" + monthNum);

System.out.println("当前时间向前推6天：" + LocalDateTime.now().minusDays(6));
System.out.println("当前时间向前推6小时：" + LocalDateTime.now().minusHours(6));
}

public static void main(String[] args) {
//一周从周日开始
WeekFields weekFields = WeekFields.of(DayOfWeek.SUNDAY, 7);
LocalDate today = LocalDate.now();
System.out.println(LocalDateUtil.getDateAsString(today) + "今天是今年第" + today.get(weekFields.weekOfYear()) + "周");
}

注意：在后期使用Period.between（）方法来获取，相差天数、相差月数的时候，发现只能计算同月的天数、同年的月数，不能计算隔月的天数以及隔年的月数！！！相当的坑

  System.out.println(LocalDate.now().toEpochDay() - LocalDate.now().minusDays(5).toEpochDay());

 System.out.println(LocalDate.now().until(LocalDate.now().minusDays(5),ChronoUnit.MONTHS));