日期工具类

/**
 * 日期工具类
 *
 * @author 东篱
 * @date 2022-1-22
 */
public class DateUtil {

    /**
     * 获取当前月开始时间
     *
     * @param date
     */
    public static Date beginOfMonth(Date date) {
        Calendar calendar = getCalendar();
        calendar.setTimeInMillis(date.getTime());
        calendar.add(Calendar.YEAR, 0);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);

        long timeInMillis = calendar.getTimeInMillis();
        return new Date(timeInMillis);
    }

    /**
     * 获取当前月结束时间
     *
     * @param date
     * @return
     */
    public static Date endOfMonth(Date date) {
        Calendar calendar = getCalendar();
        calendar.setTimeInMillis(date.getTime());
        calendar.add(Calendar.YEAR, 0);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);

        long timeInMillis = calendar.getTimeInMillis();
        return new Date(timeInMillis);
    }

    /**
     * 根据年月日获取日期
     *
     * @param year
     * @param month
     * @param day
     * @return
     */
    public static Date getDate(int year, int month, int day) {
        return dateStrParse(year + SettleConst.LINE + month + SettleConst.LINE + day, SettleConst.DATE_FORMAT);
    }

    /**
     * 根据年月日时分秒获取时间
     *
     * @param year
     * @param month
     * @param day
     * @param time
     * @return
     */
    public static Date getTime(int year, int month, int day, String time) {
        return dateStrParse(year + SettleConst.LINE + month + SettleConst.LINE + day + SettleConst.BLANK + time, SettleConst.TIME_FORMAT);
    }

    /**
     * 日期字符串转date
     *
     * @param str    日期字符串
     * @param format 格式
     * @return
     */
    public static Date dateStrParse(String str, String format) {
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        Date parse = null;
        try {
            parse = sdf.parse(str);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return parse;
    }

    /**
     * 日期转字符串
     *
     * @param date
     * @param format
     * @return
     */
    public static String dateFormat(Date date, String format) {
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        String str = "";
        try {
            if (date != null){
                str = sdf.format(date);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return str;
    }

    /**
     * 获取当前日期前某天或后某天
     *
     * @param date
     * @param days
     * @return
     */
    public static Date offsetDate(Date date, int days) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DAY_OF_MONTH, days);
        return calendar.getTime();
    }

    /**
     * 获取当前日期月份
     *
     * @param date
     * @return
     */
    public static Integer month(Date date) {
        if (date == null) {
            return -1;
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(date.getTime());
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 获取当前日期是几号
     *
     * @param date
     * @return
     */
    public static Integer day(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(date.getTime());
        return calendar.get(Calendar.DATE);
    }

    /**
     * 获取当前日期年份
     *
     * @param date
     * @return
     */
    public static Integer year(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(date.getTime());
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 获取当前季度开始时间
     *
     * @param date
     * @return
     */
    public static Date beginOfQuart(Date date) {
        Integer month = month(date);
        Integer quartStartMonth = 1;

        if (month >= 4 && month <= 6) {
            quartStartMonth = 4;
        } else if (month >= 7 && month <= 9) {
            quartStartMonth = 7;
        } else if (month >= 10 && month <= 12) {
            quartStartMonth = 10;
        }

        Calendar calendar = getCalendar();
        calendar.setTimeInMillis(date.getTime());
        calendar.add(Calendar.YEAR, 0);
        calendar.set(Calendar.MONTH, quartStartMonth - 1);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);

        return new Date(calendar.getTimeInMillis());
    }

    /**
     * 获取当前季度结束时间
     *
     * @param date
     * @return
     */
    public static Date endOfQuart(Date date) {
        Integer month = month(date);
        Integer quartStartMonth = 3;

        if (month >= 4 && month <= 6) {
            quartStartMonth = 6;
        } else if (month >= 7 && month <= 9) {
            quartStartMonth = 9;
        } else if (month >= 10 && month <= 12) {
            quartStartMonth = 12;
        }

        Calendar calendar = getCalendar();
        calendar.setTimeInMillis(date.getTime());
        calendar.add(Calendar.YEAR, 0);
        calendar.set(Calendar.MONTH, quartStartMonth - 1);
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);

        return new Date(calendar.getTimeInMillis());
    }

    public static Calendar getCalendar() {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeZone(TimeZone.getTimeZone(SettleConst.TIMEZONE));
        return calendar;
    }

    /**
     * 获取两个日期间隔的天数
     * @param minDate
     * @param maxDate
     * @return
     */
    public static Long betweenDay(Date minDate, Date maxDate) {
        long maxTime = maxDate == null ? 0L : maxDate.getTime();
        long minTime = minDate == null ? 0L : minDate.getTime();

        Long day = (maxTime - minTime) / (1000 * 3600 * 24);
        return day + 1;
    }

    /**
     * 向前/向后偏移月份
     * @param date
     * @param month
     * @return
     */
    public static Date offsetMonth(Date date, Integer month) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(date.getTime());
        calendar.add(Calendar.MONTH, month);

        return new Date(calendar.getTimeInMillis());
    }


    public static void main(String[] args) {
    }

}