package com.panzhihua.common.utlis;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.*;

import cn.hutool.core.date.DateUnit;
import cn.hutool.core.date.DateUtil;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class DateUtils {

    public static DateTimeFormatter format_ymdhms = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    public static DateTimeFormatter format_ymd = DateTimeFormatter.ofPattern("yyyy-MM-dd");
    public static DateTimeFormatter format_ymdhms_string = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
    public static DateTimeFormatter format_ymdhms_yyyyMMddmmHHssSSS = DateTimeFormatter.ofPattern("yyyyMMddmmHHssSSS");
    public static DateTimeFormatter format_ymdhms_no_signal = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
    public static SimpleDateFormat yyyyMMdd_format = new SimpleDateFormat("yyyy-MM-dd");
    public static SimpleDateFormat yyyy_MM_dd_format = new SimpleDateFormat("yyyy/MM/ddHH:mm:ss");
    public static SimpleDateFormat ymdhms_format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    public static SimpleDateFormat ymdhm_format = new SimpleDateFormat("yyyy-MM-dd HH:mm");
    public static DateTimeFormatter format_ymd_String = DateTimeFormatter.ofPattern("yyMMdd");
    public static SimpleDateFormat yyyyMM_format = new SimpleDateFormat("yyyy-MM");
    public static SimpleDateFormat format_yyymmdd = new SimpleDateFormat("yyyyMMdd");
    public static SimpleDateFormat format_yyyy = new SimpleDateFormat("yyyy");
    public static SimpleDateFormat format_yyyyMMddHHmmss = new SimpleDateFormat("yyyyMMddHHmmss");
    private static DateTimeFormatter format_ymdhmssss = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
    private static DateTimeFormatter format_ymds = DateTimeFormatter.ofPattern("yyyyMMdd");
    private static DateTimeFormatter format_yms = DateTimeFormatter.ofPattern("yyyyMM");
    private static DateTimeFormatter format_y = DateTimeFormatter.ofPattern("yyyy");

    /**
     * 将日期对象格式化成指定的字符串格式
     *
     * @param date
     *            日期对象
     * @param formatString
     *            格式化字符串
     * @return String
     */
    public static String getDateFormatString(Date date, String formatString) {

        String dateString = "";
        SimpleDateFormat format = new SimpleDateFormat(formatString);
        if (date != null) {
            dateString = format.format(date);
        }
        return dateString;
    }

    /**
     * 字符串转date
     *
     * @param date
     *            时间戳
     * @param format
     *            format
     * @return 时间
     */
    public static Date stringToDate(String date, SimpleDateFormat format) {
        try {
            if (StringUtils.isBlank(date)) {
                return null;
            }
            return format.parse(date);
        } catch (ParseException e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }

    /**
     * 字符串转date
     *
     * @param date
     *            时间戳
     * @return 时间
     */
    public static Date stringToDateStandard(String date) {
        SimpleDateFormat format = ymdhms_format;
        if (StringUtils.isNotBlank(date)) {
            if (date.split("-").length == 3) {
                if (date.split(":").length != 3) {
                    format = yyyyMMdd_format;
                }
            } else if (date.split("-").length == 2) {
                format = new SimpleDateFormat("yyyy-MM");
            }
            try {
                return format.parse(date);
            } catch (ParseException e) {
                log.error(e.getMessage(), e);
            }
        }
        return null;
    }

    /**
     * 字符串转date
     *
     * @param date
     *            时间戳
     * @return 时间
     */
    public static Date stringToDateStandardByYYYY_MM_dd(String date) {
        SimpleDateFormat format = yyyy_MM_dd_format;
        if (StringUtils.isNotBlank(date)) {
            try {
                return format.parse(date);
            } catch (ParseException e) {
                log.error(e.getMessage(), e);
            }
        }
        return null;
    }

    /**
     * 获取当前时间
     *
     * @return
     * @throws Exception
     */
    public static LocalDateTime getCurrentDate() {
        LocalDateTime now = LocalDateTime.now();
        return now;
    }

    /**
     * 返回当前事件的时间戳
     *
     * @return
     */
    public static Long getCurrentDateTimeStamp() {
        return LocalDateTime.now().toInstant(ZoneOffset.of("+8")).toEpochMilli();
    }

    /**
     * 获取当前时间字符串，格式为yyyy-MM-dd HH:mm:ss
     *
     * @return
     */
    public static String getCurrentDateStr() {
        String nowtime = getCurrentDate().format(format_ymdhms);
        return nowtime;
    }

    public static String getCurrentDateymd() {
        String nowtime = getCurrentDate().format(format_ymdhms_string);
        return nowtime;
    }

    public static String getCurrentDateyymd() {
        String nowtime = getCurrentDate().format(format_ymd_String);
        return nowtime;
    }

    /**
     * 获取当前时间字符串，格式为yyyyMMdd
     *
     * @return
     */
    public static String getCurrentDateString() {
        String nowtime = getCurrentDate().format(format_ymds);
        return nowtime;
    }

    /**
     * 获取当前时间字符串，格式为yyyy-MM-dd
     *
     * @return
     */
    public static String getCurrentDateStrymd() {
        String nowtime = getCurrentDate().format(format_ymd);
        return nowtime;
    }

    public static String getCurrentDateStr_MS() {
        String nowtime = getCurrentDate().format(format_ymdhmssss);
        return nowtime;
    }

    /**
     * 获取当前时间long值
     *
     * @return
     */
    public static long getCurrentDataLong() {
        return new Date().getTime();
    }

    /**
     * 获取当前时间
     *
     * @param format
     * @return
     * @throws Exception
     */
    public static Date getCurrentDate(SimpleDateFormat format) {
        String tempDate = format.format(new Date());
        try {
            return format.parse(tempDate);
        } catch (ParseException e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }

    /**
     * @param date
     * @param newFormat
     * @return
     * @throws Exception
     */
    public static Date getDate(Date date, SimpleDateFormat newFormat) {
        String tempDate = newFormat.format(date);
        try {
            return newFormat.parse(tempDate);
        } catch (ParseException e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }

    public static String format(Date date, SimpleDateFormat format) {
        if (null == date) {
            return "";
        }
        return format.format(date);
    }

    /**
     * 将给定的时间秒转换为中文格式的时分秒
     *
     * @param second
     * @return
     */
    public static String formatSecond_ZH_HMS(Integer second) {
        String result = "0秒";
        if (null != second) {
            int hours = second / (60 * 60);
            int minutes = second / 60 - hours * 60;
            int seconds = second - minutes * 60 - hours * 60 * 60;

            String format;
            Object[] array;

            if (hours > 0) {
                format = "%1$,d时%2$,d分%3$,d秒";
                array = new Object[] {hours, minutes, seconds};
            } else if (minutes > 0) {
                format = "%1$,d分%2$,d秒";
                array = new Object[] {minutes, seconds};
            } else {
                format = "%1$,d秒";
                array = new Object[] {seconds};
            }
            result = String.format(format, array);
        }
        return result;
    }

    /**
     * 对日期进行加法操作
     *
     * @param date
     * @param days
     * @return
     */
    public static Date addDay(Date date, Integer days) {
        if (null != date) {
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            cal.add(Calendar.DATE, days);
            return cal.getTime();
        }
        return null;
    }

    /**
     * 对日期进行加法操作
     *
     * @param date
     * @param month
     * @return
     */
    public static Date addMonth(Date date, Integer month) {
        if (null != date) {
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            cal.add(Calendar.MONTH, month);
            return cal.getTime();
        }
        return null;
    }

    /**
     * 对日期进行加法操作
     *
     * @param date
     * @param hours
     * @return
     */
    public static Date addHours(Date date, Integer hours) {
        if (null != date) {
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            cal.add(Calendar.HOUR_OF_DAY, hours);
            return cal.getTime();
        }
        return null;
    }

    /**
     * 对日期的分钟进行加法操作
     *
     * @param date
     * @param minutes
     * @return
     */
    public static Date addMinutes(Date date, Integer minutes) {
        if (null != date) {
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            cal.add(Calendar.MINUTE, minutes);
            return cal.getTime();
        }
        return null;
    }

    /**
     * 比较两个日期的大小
     *
     * @param date1
     * @param date2
     * @return 日期相等，返回0；前者大，返回1；后者大，返回-1；
     */
    public static int dateCompare(Date date1, Date date2) {
        Calendar c1 = Calendar.getInstance();
        c1.setTime(date1);

        Calendar c2 = Calendar.getInstance();
        c2.setTime(date2);

        return c1.compareTo(c2);
    }

    /**
     * 判断当前日期是否在指定日期区域内(包含起止日期) [startDate,endDate]
     * <p/>
     * [null,null] --> return 1;
     *
     * @param now
     * @param startDate
     * @param endDate
     * @return -1：超出并小于startDate；0:在范围内；1：超出并大于endDate；
     */
    public static int validateDate(Date now, Date startDate, Date endDate) {
        if (null == startDate && null == endDate) {
            return 0;
        }
        if (null == startDate) {
            // 当前时间大于endDate
            if (dateCompare(now, endDate) == 1) {
                return 1;
            } else {
                return 0;
            }
        } else {
            if (null == endDate) {
                // 当前时间小于startDate
                if (dateCompare(startDate, now) == 1) {
                    return -1;
                } else {
                    return 0;
                }
            } else {
                if (dateCompare(startDate, now) == 1) {
                    return -1;
                } else if (dateCompare(now, endDate) == 1) {
                    return 1;
                } else {
                    return 0;
                }
            }
        }
    }

    /**
     * 计算两个日期先差多少秒
     *
     * @param pre
     *            前一个日期
     * @param after
     *            后一个日期
     * @return
     */
    public static long calTimeDifference(Date pre, Date after) {
        return (after.getTime() - pre.getTime()) / 1000;
    }

    /**
     * 计算两个时间相差的天数
     *
     * @param stardate
     * @param enddate
     * @return
     */
    public static int getHour(Date stardate, Date enddate) {
        long nd = 1000 * 24 * 60 * 60;
        long nh = 1000 * 60 * 60;
        long nm = 1000 * 60;
        long diff = enddate.getTime() - stardate.getTime();

        long day = diff / nd;

        long hour = diff / nh;

        long min = diff / nm;

        return (int)hour;
    }

    /**
     * 结束时间与当前时间计算相差的月数
     *
     * @param enddate
     * @return
     */
    public static int getMonthSpace(String enddate, DateTimeFormatter format) {
        LocalDate formatted = LocalDate.parse(enddate, format);
        LocalDate today = LocalDate.now();
        Period per = Period.between(today, formatted);
        if (per.getYears() == 0) {
            return per.getMonths();
        } else if (per.getYears() > 0) {
            return (per.getYears() * 12) + per.getMonths();
        }

        return (per.getYears() * 12) + per.getMonths();
    }

    /**
     * 获取某个时间段之前的时间点
     *
     * @return
     */
    public static String getSomeTimeStapStr(String sign) {
        LocalDateTime beginDateTime = null;
        if (sign.equals("day")) {// 一天前时间
            beginDateTime = LocalDateTime.now().minusDays(1L);
        } else if (sign.equals("week")) {
            beginDateTime = LocalDateTime.now().minusWeeks(1L);
        } else if (sign.equals("month")) {
            beginDateTime = LocalDateTime.now().minusMonths(1L);
        } else if (sign.equals("year")) {
            beginDateTime = LocalDateTime.now().minusYears(1L);
        }
        String beginTime = beginDateTime.format(format_ymdhms);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            long timestap = sdf.parse(beginTime).getTime();
            beginTime = timestap + "";
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return beginTime;
    }

    public static String getSomeTimeDateStr(String sign) {
        String beginTime = "";
        LocalDateTime beginDateTime = null;
        if (sign.equals("day")) {// 一天前时间
            beginDateTime = LocalDateTime.now().minusDays(1L);
        } else if (sign.equals("week")) {
            beginDateTime = LocalDateTime.now().minusWeeks(1L);
        } else if (sign.equals("month")) {
            beginDateTime = LocalDateTime.now().minusMonths(1L);
        } else if (sign.equals("year")) {
            beginDateTime = LocalDateTime.now().minusYears(1L);
        }
        if (beginDateTime != null) {
            beginTime = beginDateTime.format(format_ymdhms);
        }
        return beginTime;
    }

    /**
     * 获取失效时间点（在什么时间失效）
     *
     * @param minutes
     *            有效分钟数
     * @return
     */
    public static LocalDateTime getInvalidLocalDateTime(Long minutes) {
        return LocalDateTime.now().minusMinutes(minutes);
    }

    /**
     * 获取当前年份
     *
     * @return
     */
    public static String getCurrentYear() {
        Calendar instance = Calendar.getInstance();
        return instance.get(Calendar.YEAR) + "";
    }

    /**
     * 获取当前月份
     *
     * @return
     */
    public static String getCurrentMonth() {
        Calendar instance = Calendar.getInstance();
        int month = instance.get(Calendar.MONTH);
        String result;
        if (month < 10) {
            result = "0" + month;
        } else {
            result = month + "";
        }
        return result;
    }

    /**
     * 获取无符号的当前时间
     *
     * @return
     */
    public static String getCurrentDateStrNoSignal() {
        return getCurrentDate().format(format_ymdhms_no_signal);
    }

    /**
     * 获取前几个小时的时间
     *
     * @param hours
     * @return
     */
    public static String getNextHourDateStrNoSignal(long hours) {
        return LocalDateTime.now().plusHours(hours).format(format_ymdhms_no_signal);
    }

    public static Date localDateTimeToDate(LocalDateTime localDateTime) {
        ZoneId zone = ZoneId.systemDefault();
        Instant instant = localDateTime.atZone(zone).toInstant();
        return Date.from(instant);
    }

    /**
     * 小时取整
     *
     * @param date
     * @param hour
     * @return
     */
    public static Date integralHour(Date date, Integer hour) {
        if (date == null || hour == null) {
            return null;
        }
        long l = date.getTime() - 1;
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:00:00");
        try {
            Date parse = sdf.parse(sdf.format(new Date(l)));
            return addHours(parse, hour);
        } catch (ParseException e) {
            return null;
        }
    }

    /**
     * 分钟取整 以十分钟为单位 ，去除尾端，加上 参数 46->40+minutes*10
     *
     * @param date
     * @param minutes
     * @return
     */
    public static Date integral10Min(Date date, Integer minutes) {
        if (date == null || minutes == null) {
            return null;
        }
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int i = cal.get(Calendar.MINUTE);// 获取分钟
        if (i % 10 == 0) {
            minutes--;
        }
        minutes = minutes * 10 - i % 10;
        long l = date.getTime() - 1;
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:00");
        try {
            Date parse = sdf.parse(sdf.format(new Date(l)));
            return addMinutes(parse, minutes);
        } catch (ParseException e) {
            return null;
        }
    }

    /**
     * 天数取整
     *
     * @param date
     * @param day
     * @return
     */
    public static Date integralDay(Date date, Integer day) {
        if (date == null || day == null) {
            return null;
        }
        long l = date.getTime() - 1;
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd 00:00:00");
        try {
            Date parse = sdf.parse(sdf.format(new Date(l)));
            return addDay(parse, day);
        } catch (ParseException e) {
            return null;
        }
    }

    /**
     * 日期相加减
     *
     * @param time
     *            时间字符串 yyyy-MM-dd HH:mm:ss
     * @param num
     *            加的数，-num就是减去
     * @return 减去相应的数量的年的日期
     * @throws ParseException
     */
    public static Date yearAddNum(Date time, Integer num) {
        // SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        // Date date = format.parse(time);

        Calendar calendar = Calendar.getInstance();
        calendar.setTime(time);
        calendar.add(Calendar.YEAR, num);
        Date newTime = calendar.getTime();
        return newTime;
    }

    public static boolean isValidDate(String str) {
        boolean convertSuccess = true;
        SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd");
        try {
            format.setLenient(false);
            format.parse(str);
        } catch (ParseException e) {
            convertSuccess = false;
        }
        return convertSuccess;
    }

    public static Date toValidDate(String str) {
        Date date = null;
        SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd");
        try {
            format.setLenient(false);
            date = format.parse(str);
        } catch (ParseException e) {
            log.error("党员导入日期格式错误");
            date = new Date();
        }
        return date;
    }

    /**
     * 将日期对象格式化成yyyy-MM-dd格式的字符串
     *
     * @param date
     *            日期对象
     * @return String
     */
    public static String getDateStringYMD(Date date) {

        String dateString = "";
        if (date != null) {
            dateString = yyyyMMdd_format.format(date);
        }
        return dateString;
    }

    /**
     * 获取当前月第一天
     *
     * @return
     */
    public static Date getFirstDayOfMonth() {
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.MONTH, 0);
        int actualMinimum = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), actualMinimum, 00, 00, 00);
        return cal.getTime();
    }

    /**
     * 获取当前年月的第一天时间
     *
     * @param year
     *            年份
     * @param month
     *            月份
     * @return 时间
     */
    public static Date getYearMonthStart(Integer year, Integer month) {
        Calendar cal = Calendar.getInstance();
        // 设置年份
        cal.set(Calendar.YEAR, year);
        // 设置月份
        cal.set(Calendar.MONTH, month - 1);
        // 获取某月最小天数
        int firstDay = cal.getMinimum(Calendar.DATE);
        // 设置日历中月份的最小天数
        cal.set(Calendar.DAY_OF_MONTH, firstDay);
        int actualMinimum = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), actualMinimum, 00, 00, 00);
        return cal.getTime();
    }

    /**
     * 获取当前年月的最后一天时间
     *
     * @param year
     *            年份
     * @param month
     *            月份
     * @return 时间
     */
    public static Date getYearMonthEnd(Integer year, Integer month) {
        Calendar cal = Calendar.getInstance();
        // 设置年份
        cal.set(Calendar.YEAR, year);
        // 设置月份
        cal.set(Calendar.MONTH, month - 1);
        // 获取某月最大天数
        int lastDay = cal.getMaximum(Calendar.DATE);
        // 设置日历中月份的最大天数
        cal.set(Calendar.DAY_OF_MONTH, lastDay);
        int actualMinimum = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), actualMinimum, 00, 00, 00);
        return cal.getTime();
    }

    public static Date getDateM(Date start, int min) {
        Calendar date1 = Calendar.getInstance();
        date1.setTime(start);
        date1.add(Calendar.MONTH, min);
        return date1.getTime();
    }

    public static Date parseDateYM(String str) {
        try {
            return yyyyMM_format.parse(str);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static int getMonth(Date date) {
        Calendar instance = Calendar.getInstance();
        instance.setTime(date);
        return instance.get(Calendar.MONTH);
    }

    public static int getYear(Date date) {
        Calendar instance = Calendar.getInstance();
        instance.setTime(date);
        return instance.get(Calendar.YEAR);
    }

    public static boolean before(Date start, Date end) {
        Calendar date1 = Calendar.getInstance();
        date1.setTime(start);
        Calendar date2 = Calendar.getInstance();
        date2.setTime(end);
        return date1.before(date2);
    }

    /**
     * date2比date1多的天数
     *
     * @param date1
     * @param date2
     * @return
     */
    public static int differentDays(Date date1, Date date2) {
        Calendar cal1 = Calendar.getInstance();
        cal1.setTime(date1);

        Calendar cal2 = Calendar.getInstance();
        cal2.setTime(date2);
        int day1 = cal1.get(Calendar.DAY_OF_YEAR);
        int day2 = cal2.get(Calendar.DAY_OF_YEAR);

        int year1 = cal1.get(Calendar.YEAR);
        int year2 = cal2.get(Calendar.YEAR);
        if (year1 != year2) // 同一年
        {
            int timeDistance = 0;
            for (int i = year1; i < year2; i++) {
                if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0) // 闰年
                {
                    timeDistance += 366;
                } else // 不是闰年
                {
                    timeDistance += 365;
                }
            }

            return timeDistance + (day2 - day1);
        } else // 不同年
        {
            // System.out.println("判断day2 - day1 : " + (day2-day1));
            return day2 - day1;
        }
    }

    /**
     * 计算剩余天数，不足一天按一天算
     * @param expireDate
     * @return
     */
    public static int retrieveRemainingDays(Date expireDate) {
        Date nowDate = new Date();
        Calendar startDate = Calendar.getInstance();
        startDate.setTime(nowDate);
        Calendar endDate = Calendar.getInstance();
        endDate.setTime(expireDate);
        Calendar date = (Calendar) startDate.clone();
        int daysBetween = 0;
        while (date.before(endDate)) {
            date.add(Calendar.DAY_OF_MONTH, 1);
            daysBetween++;
        }
        return daysBetween;
    }

    /**
     * 获取当前月第一天
     *
     * @return
     */
    public static String getFirstDayOfMonthString() {
        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.MONTH, 0);

        calendar.set(Calendar.DAY_OF_MONTH, 1);
        // 格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        return sdf.format(calendar.getTime()) + " 00:00:00";
    }

    /**
     * 获取当前月最后一天
     *
     * @return
     */
    public static String getLastDayOfMonthString() {
        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.MONTH, 1);

        calendar.set(Calendar.DAY_OF_MONTH, 0);
        // 格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        return sdf.format(calendar.getTime()) + " 23:59:59";
    }
    /**
     * 获取当前月最后一天
     *
     * @return
     */
    public static Date getLastDayOfMonth() {
        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.MONTH, 1);

        calendar.set(Calendar.DAY_OF_MONTH, 0);
        // 格式化日期

        return calendar.getTime();
    }

    /**
     * 获取当前时间（年月日）
     *
     * @return
     */
    public static String getDayOfMonthString() {
        Calendar today = Calendar.getInstance();
        today.set(Calendar.HOUR, 0);
        today.set(Calendar.MINUTE, 0);
        today.set(Calendar.SECOND, 0);
        today.set(Calendar.MILLISECOND, 0);
        // 格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        return sdf.format(today.getTime());
    }

    /**
     * 日期转周
     *
     * @param datetime
     * @return
     */
    public static String dateToWeek(String datetime) {
        SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");
        String[] weekDays = {"周日", "周一", "周二", "周三", "周四", "周五", "周六"};
        Calendar cal = Calendar.getInstance(); // 获得一个日历
        Date datet = null;
        try {
            if (StringUtils.isNotEmpty(datetime)) {
                datet = f.parse(datetime);
                cal.setTime(datet);
            }
        } catch (ParseException e) {
            e.printStackTrace();
        }
        int w = cal.get(Calendar.DAY_OF_WEEK) - 1; // 指示一个周中的某天。
        if (w < 0)
            w = 0;
        return weekDays[w];
    }

    public static void main(String[] args) throws Exception {
//        List<String> beforeDays = getBeforeDays(15);
//        System.out.println(beforeDays);
        List<String> yearMonths = getYearMonths();
        System.out.println(yearMonths);
        List<String> latest12Month = getLatest12Month(LocalDate.now(), 10);
        System.out.println(latest12Month);

    }

    /**
     * 获取当前年月字符串
     * @return  年月字符串
     */
    public static String getCurrentDateString_YYYY_MM() {
        String nowtime = getCurrentDate().format(format_yms);
        return nowtime;
    }

    /**
     * 获取当前年字符串
     * @return
     */
    public static String getCurrentDateString_YYYY() {
        String nowtime = getCurrentDate().format(format_y);
        return nowtime;
    }

    /**
     * 获取当前年第一天
     * @return  当前年第一天时间
     */
    public static Date getFirstDayOfYear() {
        Calendar currCal=Calendar.getInstance();
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearFirst(currentYear);
    }

    /**
     * 获取某年第一天日期
     * @param year 年份
     * @return Date
     */
    public static Date getYearFirst(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        Date currYearFirst = calendar.getTime();
        return currYearFirst;
    }

    /**
     * 获取上月第一天时间
     * @return  上月第一天时间
     */
    public static Date getLastMonthFirst(){
        // 上月起始
        Calendar lastMonthFirstDateCal = Calendar.getInstance();
        lastMonthFirstDateCal.add(Calendar.MONTH,-1);
        lastMonthFirstDateCal.set(Calendar.DAY_OF_MONTH, 1);
        String lastMonthFirstTime = yyyyMMdd_format.format(lastMonthFirstDateCal.getTime()) + " 00:00:00";
        return stringToDateStandard(lastMonthFirstTime);
    }

    /**
     * 获取上月最后一天时间
     * @return  最后一天时间
     */
    public static Date getLastMonthEnd(){
        // 上月末尾
        Calendar lastMonthEndDateCal = Calendar.getInstance();
        lastMonthEndDateCal.add(Calendar.MONTH,-1);
        lastMonthEndDateCal.set(Calendar.DAY_OF_MONTH, lastMonthEndDateCal.getActualMaximum(Calendar.DAY_OF_MONTH));
        String lastMonthEndTime = yyyyMMdd_format.format(lastMonthEndDateCal.getTime()) + " 23:59:59";
        return stringToDateStandard(lastMonthEndTime);
    }

    /**
     * 获取近20天日期
     * @return  近20天日期
     */
    public static List<Date> getOldDays() {
        List<Date> dates = new ArrayList<>();
        Date date = new Date();
        for (int i = 19; i >= 0; i--) {
            Date date1 = DateUtils.addDay(date, -i);
            dates.add(date1);
        }
        return dates;
    }

    /**
     * 获取上月最后一天时间
     * @return  上月最后一天时间
     */
    public static String getOldMonthLastDay(){
        Calendar calendar=Calendar.getInstance();
        int month=calendar.get(Calendar.MONTH);
        calendar.set(Calendar.MONTH, month-1);
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        return format_yyymmdd.format(calendar.getTime());
    }

    /**
     * 获取上月第一天时间
     * @return  上月第一天时间
     */
    public static String getOldMonthFirstDay(){
        Calendar calendar=Calendar.getInstance();
        calendar.add(Calendar.MONTH, -1);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        return format_yyymmdd.format(calendar.getTime());
    }

    /**
     * 获取某年的月份最后一天时间
     * @param year  年份
     * @return  月份list
     */
    public static List<String> getYearLastMonths(Integer year){
        List<String> list = new ArrayList<>();
        list.add(getLastDayOfMonth(year,1));
        list.add(getLastDayOfMonth(year,2));
        list.add(getLastDayOfMonth(year,3));
        list.add(getLastDayOfMonth(year,4));
        list.add(getLastDayOfMonth(year,5));
        list.add(getLastDayOfMonth(year,6));
        list.add(getLastDayOfMonth(year,7));
        list.add(getLastDayOfMonth(year,8));
        list.add(getLastDayOfMonth(year,9));
        list.add(getLastDayOfMonth(year,10));
        list.add(getLastDayOfMonth(year,11));
        list.add(getLastDayOfMonth(year,12));
        return list;
    }

    /**
     * 获取某年的月份第一天时间
     * @param year  年份
     * @return  月份list
     */
    public static List<String> getYearFirstMonths(Integer year){
        List<String> list = new ArrayList<>();
        list.add(getFirstDayOfMonth(year,1));
        list.add(getFirstDayOfMonth(year,2));
        list.add(getFirstDayOfMonth(year,3));
        list.add(getFirstDayOfMonth(year,4));
        list.add(getFirstDayOfMonth(year,5));
        list.add(getFirstDayOfMonth(year,6));
        list.add(getFirstDayOfMonth(year,7));
        list.add(getFirstDayOfMonth(year,8));
        list.add(getFirstDayOfMonth(year,9));
        list.add(getFirstDayOfMonth(year,10));
        list.add(getFirstDayOfMonth(year,11));
        list.add(getFirstDayOfMonth(year,12));
        return list;
    }

    /**
     * 获取某年某月最后一天
     * @param year  年份
     * @param month 月份
     * @return  某年某月最后一天
     */
    public static String getLastDayOfMonth(int year,int month)
    {
        Calendar cal = Calendar.getInstance();
        //设置年份
        cal.set(Calendar.YEAR,year);
        //设置月份
        cal.set(Calendar.MONTH, month-1);
        //获取某月最大天数
        int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        //设置日历中月份的最大天数
        cal.set(Calendar.DAY_OF_MONTH, lastDay);
        //格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String lastDayOfMonth = sdf.format(cal.getTime());
        return lastDayOfMonth;
    }

    /**
     *  获取某年某月的第一天
     * @param year  年份
     * @param month 月份
     * @return  某年某月第一天
     */
    public static String getFirstDayOfMonth(int year,int month)
    {
        Calendar cal = Calendar.getInstance();
        //设置年份
        cal.set(Calendar.YEAR,year);
        //设置月份
        cal.set(Calendar.MONTH, month-1);
        //获取某月最小天数
        int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        //设置日历中月份的最小天数
        cal.set(Calendar.DAY_OF_MONTH, firstDay);
        //格式化日期
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String firstDayOfMonth = sdf.format(cal.getTime());

        return firstDayOfMonth;
    }

    /**
     * 获取20天前那天时间
     *
     * @return
     */
    public static String getTwentyDay() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(new Date());
        cal.add(Calendar.DATE, -20);

        return DateUtil.format(cal.getTime(),"yyyy-MM-dd");
    }

    /**
     * 获取之前的日期
     *
     * @return
     */
    public static String getBeforeDay(Integer amount) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(new Date());
        cal.add(Calendar.DATE, -amount);
        return DateUtil.format(cal.getTime(),"yyyy-MM-dd");
    }

    /**
     * 获取最近本月20天数据
     *
     * @return
     */
    public static String getMonthTwentyDay() {
        Date date = new Date();
        Long offset = DateUtil.between(new Date(), DateUtil.beginOfMonth(date), DateUnit.DAY);
        if (offset >= 20) {
            return getTwentyDay();
        } else {
            //距离月初不足20天
            Calendar calendar = new GregorianCalendar();
            calendar.setTime(date);
            //获得本月第一天
            calendar.add(Calendar.MONTH, 0);
            calendar.set(Calendar.DAY_OF_MONTH, 1);
            return DateUtil.format(calendar.getTime(),"yyyy-MM-dd");
        }

    }

    public static List<String> getBeforeDays(int before) {
        List<String> dates = new ArrayList<>();
        for (int i = before; i >= 0; i--) {
            dates.add(getBeforeDay(i));
        }
        return dates;
    }

    /**
     * 获取当年所有月份
     *
     * @return
     */
    public static List<String> getYearMonths() {
        Calendar instance = Calendar.getInstance();
        int year = instance.get(Calendar.YEAR);
        List<String> months = new ArrayList<>();
        for (int i = 1; i <= 12; i++) {
            String result = String.valueOf(year);
            if (i < 10) {
                result = result + "-0" +i;
            } else {
                result = result + "-"+i;
            }
            months.add(result);
        }
        return months;
    }

    //获取当前12个月
    public static List<String> getLatest12Month(LocalDate date,int num){
        List<String> monthList = new ArrayList<>();
        for(int i = 0;i <= num-1; i++){
            LocalDate localDate = date.minusMonths(i);
            String month = localDate.toString().substring(0,7);
            monthList.add(month);
        }
        return monthList;
    }


}