import java.text.DecimalFormat;
import java.time.*;

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;

import java.time.temporal.TemporalAdjusters;
import java.time.temporal.WeekFields;

import java.util.Calendar;
import java.util.Date;


public class DateUtil {


   // private static final  DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");


    public static void main(String[] args) {
        System.out.println(getDayFirst(new Date()));
        System.out.println(getDayEnd(new Date()));

        System.out.println(getDayFirstTodayEight(new Date()));
        System.out.println(getMonthFirstDay());

        System.out.println(getTimesMonthLastDay());
        System.out.println(week(new Date()));
        System.out.println(month(new Date()));

        LocalDate end = LocalDate.of(2018, 12, 26);
        LocalDate start = LocalDate.of(1994, 10, 28);
        System.out.println(end.toEpochDay() - start.toEpochDay());



    }


    // 获取传入日期的初始时间
    public static Date getDayFirst(Date date) {
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();

        LocalDateTime today_start = LocalDateTime.of(localDate, LocalTime.MIN);

        ZonedDateTime zdt = today_start.atZone(zoneId);
         return Date.from(zdt.toInstant());

//
    }


    // 获取传入日期的 8點
    public static Date getDayFirstTodayEight( Date date) {

        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();
        LocalDateTime today_start = localDate.atTime(8,0,0);

        ZonedDateTime zdt = today_start.atZone(zoneId);
        return Date.from(zdt.toInstant());

    }




    //獲取傳入日期的結束時間
    public static Date getDayEnd(Date endTime) {



        Instant instant = endTime.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();
        LocalDateTime today_start = LocalDateTime.of(localDate, LocalTime.MAX);

        ZonedDateTime zdt = today_start.atZone(zoneId);
        return Date.from(zdt.toInstant());
    }

    /**
     * 计算当前时间的年份
     *
     * @return
     */
    public static int year(Date date) {
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();

        return localDate.getYear();

    }





    //获取传入日期的月份
    public static int month(Date date) {
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();

        return localDate.getMonth().getValue();
    }


    // 计算目前是一年中的第几周
    public static int week(Date date) {
//
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = instant.atZone(zoneId).toLocalDate();

        WeekFields weekFields = WeekFields.of(DayOfWeek.MONDAY,1);
        return localDate.get(weekFields.weekOfWeekBasedYear());


    }



    /**
     * 获取本月第一天的日期
     *
     * @return
     */
    public static Date getMonthFirstDay() {

        LocalDateTime today_start = LocalDateTime.of(LocalDate.now(), LocalTime.MIN);

        LocalDateTime firstday = today_start.with(TemporalAdjusters.firstDayOfMonth());

        ZoneId zoneId = ZoneId.systemDefault();

        ZonedDateTime zdt = firstday.atZone(zoneId);
        return Date.from(zdt.toInstant());
    }

    /**
     * 获取本月最后一天日期
     *
     * @return
     */
    public static Date getTimesMonthLastDay() {

        LocalDateTime today_start = LocalDateTime.of(LocalDate.now(), LocalTime.MAX);
        LocalDateTime firstday = today_start.with(TemporalAdjusters.lastDayOfMonth());
        ZoneId zoneId = ZoneId.systemDefault();
        ZonedDateTime zdt = firstday.atZone(zoneId);
        return Date.from(zdt.toInstant());
    }


    public static Date MaxDate(Date beginDate, Date endDate) {
        if (endDate.getTime() > beginDate.getTime()) {
            return endDate;
        } else if (endDate.getTime() < beginDate.getTime()) {
            return beginDate;

        }
        return beginDate;

    }






//    /**
//     * 计算2个日期之间的相差的小时数
//     *
//     * @param endDate
//     * @param nowDate
//     * @return
//     */
//    public static Double getDateFloat(Date endDate, Date nowDate) {
//
//        long nd = 1000 * 24 * 60 * 60;
//        long nh = 1000 * 60 * 60;
//        long nm = 1000 * 60;
//
//        long diff = 0L;
//
//        if (endDate.getTime() > nowDate.getTime()) {
//            diff = endDate.getTime() - nowDate.getTime();
//        } else if (nowDate.getTime() > endDate.getTime()) {
//            diff = nowDate.getTime() - endDate.getTime();
//        }
//        /**
//         * 计算差多少天
//         */
//        long day = diff / nd;
//
//        /**
//         * 计算差多少小时
//         */
//        long hour = diff % nd / nh;
//
//        /**
//         * 计算差多少分钟
//         */
//        long min = diff % nd % nh / nm;
//        Double a = min / 60.0;
//
//
//        // 计算差多少秒,输出结果
//        BigDecimal b = new BigDecimal(a);
//        Double f1 = b.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
//        return (Double) (day * 24 + hour + f1);
//    }


    public static String LocalDateTimeHourMinus( Date startTime, Date endTime){

        ZoneId zoneId = ZoneId.systemDefault();//A time-zone ID, such as {@code Europe/Paris}.(时区)

        Instant instantstart = startTime.toInstant();//An instantaneous point on the time-line.(时间线上的一个瞬时点。)

        LocalDateTime startlocalDateTime = instantstart.atZone(zoneId).toLocalDateTime();

        Instant instantend = endTime.toInstant();

        LocalDateTime endlocalDateTime = instantend.atZone(zoneId).toLocalDateTime();

        ZoneId zone = ZoneId.systemDefault();
        Instant instantStart = startlocalDateTime.atZone(zone).toInstant();
        Instant instantEnd = endlocalDateTime.atZone(zone).toInstant();
        java.util.Date dateStart = Date.from(instantStart);
        java.util.Date dateEnd = Date.from(instantEnd);
        Calendar instance = Calendar.getInstance();
        instance.setTime(dateStart);
        long timeInMillis1 = instance.getTimeInMillis();
        Calendar instance2 = Calendar.getInstance();
        instance2.setTime(dateEnd);
        long timeInMillis2 = instance2.getTimeInMillis();
        //此处可根据自己需要来计算结果 天/时/分/秒
        double hours = (timeInMillis2 - timeInMillis1)/1000/60/60.0;
        DecimalFormat df = new DecimalFormat("##.#");
        String dff=df.format(hours);
        return dff;
    }




    //计算2个时间相差的 天数
    public static long  betweenourMinus( Date startTime, Date endTime) {
        {


            ZoneId zoneId = ZoneId.systemDefault();//A time-zone ID, such as {@code Europe/Paris}.(时区)

            Instant instant = startTime.toInstant();//An instantaneous point on the time-line.(时间线上的一个瞬时点。)

            LocalDateTime startlocalDateTime = instant.atZone(zoneId).toLocalDateTime();


            Instant instantend = endTime.toInstant();//An instantaneous point on the time-line.(时间线上的一个瞬时点。)

            LocalDateTime endlocalDateTime = instant.atZone(zoneId).toLocalDateTime();



            LocalDateTime now = startlocalDateTime;
            LocalDateTime end1 =endlocalDateTime;
            Duration duration = Duration.between(now, end1);
            long days = duration.toDays(); //相差的天数
            long hours = duration.toHours();//相差的小时数
            long minutes = duration.toMinutes();//相差的分钟数
            long millis = duration.toMillis();//相差毫秒数
            long nanos = duration.toNanos();//相差的纳秒数
            System.out.println(now);
            System.out.println(end1);
            System.out.println("发送短信耗时【 " + days + "天：" + hours + " 小时：" + minutes + " 分钟：" + millis + " 毫秒：" + nanos + " 纳秒】");
            return hours;
        }
    }
}