日期格式转换工具类

野性酷女 2023-10-18 16:24 144阅读 0赞

import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    
    /**
     * 日期工具
     *
     */
    public class DateTimeUtils {
    
        // public static final SimpleDateFormat FORMAT_LONG = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss SSS");
    
        public static boolean isSameDay(Calendar cal1, Calendar cal2) {
            if (cal1 == null || cal2 == null) return false;
            return (cal1.get(Calendar.ERA) == cal2.get(Calendar.ERA) && cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) && cal1
                    .get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR));
        }
    
        public static boolean isSameDay(Date date1, Date date2) {
            if (date1 == null || date2 == null) return false;
            Calendar cal1 = Calendar.getInstance();
            cal1.setTime(date1);
            Calendar cal2 = Calendar.getInstance();
            cal2.setTime(date2);
            return isSameDay(cal1, cal2);
        }
    
        public static boolean isSameInstant(Date date1, Date date2) {
            if (date1 == null || date2 == null) return false;
            return date1.getTime() == date2.getTime();
        }
    
        public static boolean isSameInstant(Calendar cal1, Calendar cal2) {
            if (cal1 == null || cal2 == null) return false;
            return cal1.getTime().getTime() == cal2.getTime().getTime();
        }
    
        public static Date addYears(Date date, int amount) {
            return add(date, Calendar.YEAR, amount);
        }
    
        public static Date addMonths(Date date, int amount) {
            return add(date, Calendar.MONTH, amount);
        }
    
        public static Date addWeeks(Date date, int amount) {
            return add(date, Calendar.WEEK_OF_YEAR, amount);
        }
    
        public static Date addDays(Date date, int amount) {
            return add(date, Calendar.DAY_OF_MONTH, amount);
        }
    
        public static Date addHours(Date date, int amount) {
            return add(date, Calendar.HOUR_OF_DAY, amount);
        }
    
        public static Date addMinutes(Date date, int amount) {
            return add(date, Calendar.MINUTE, amount);
        }
    
        public static Date addSeconds(Date date, int amount) {
            return add(date, Calendar.SECOND, amount);
        }
    
        public static Date addMilliseconds(Date date, int amount) {
            return add(date, Calendar.MILLISECOND, amount);
        }
    
        public static Date add(Date date, int calendarField, int amount) {
            if (date == null) throw new IllegalArgumentException("日期不能为空");
    
            Calendar c = Calendar.getInstance();
            c.setTime(date);
            c.add(calendarField, amount);
            return c.getTime();
        }
    
        public static String today() {
            return today("yyyy-MM-dd");
        }
    
        public static String now() {
            return today("yyyy-MM-dd HH:mm:ss SSS");
        }
    
        public static String today(String pattern) {
            if (pattern == null) throw new IllegalArgumentException("日期格式不能为空");
            SimpleDateFormat sdf = new SimpleDateFormat(pattern);
            String dt = sdf.format(new Date());
            return dt;
        }
    
        public static Date parseDate(String src) {
            return parse(src, "yyyy-MM-dd");
        }
    
        public static Date parseDatetime(String src) {
            return parse(src, "yyyy-MM-dd HH:mm:ss");
        }
    
        public static Date parse(String src, String pattern) {
            if (pattern == null) throw new IllegalArgumentException("日期格式不能为空");
            if (src == null) return null;
            try {
                return new SimpleDateFormat(pattern).parse(src);
            } catch (ParseException ex) {
                throw new IllegalArgumentException("日期格式转换出错,src=" + src + ",pattern=" + pattern);
            }
        }
    
        public static String formatDate(Date src) {
            return format(src, "yyyy-MM-dd");
        }
    
        public static String formatDatetime(Date src) {
            return format(src, "yyyy-MM-dd HH:mm:ss");
        }
    
        public static String format(Date src, String pattern) {
            if (pattern == null) throw new IllegalArgumentException("日期格式不能为空");
            if (src == null) return null;
            return new SimpleDateFormat(pattern).format(src);
        }
    
        public static int getLastDayOfMonth(int y, int m) {
            boolean IsLeapYear = (y % 4 == 0) && (y % 100 != 0) || (y % 400 == 0);
            int days = 0;
            switch (m) {
                case 2:
                    if (IsLeapYear) {
                        days = 29;
                    } else days = 28;
                    break;
                case 4:
                case 6:
                case 9:
                case 11:
                    days = 30;
                    break;
                default:
                    days = 31;
                    break;
            }
            return days;
        }
    
        /**
         * 中文星期几
         *
         * @return
         */
        public static String getCnWeekDay() {
            return getCnWeekDay(new Date());
        }
    
        /**
         * 中文星期几
         *
         * @return
         */
        public static String getCnWeekDay(Date date) {
            String[] weekDays = {"日", "一", "二", "三", "四", "五", "六"};
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
            if (w < 0) w = 0;
            return "星期" + weekDays[w];
        }
    
        /**
         * 获取当月的第一天
         * @return
         */
        public static Date getFirstDateOfCurrentMonth() {
            Calendar instance = Calendar.getInstance();
            instance.setTime(new Date());
            int year = instance.get(Calendar.YEAR);
            int month = instance.get(Calendar.MONTH);
            instance.set(year, month, 1, 0, 0, 0);
            return instance.getTime();
        }
    
        public static Date getFirstDateOfCurrentYear() {
            Calendar instance = Calendar.getInstance();
            instance.setTime(new Date());
            int year = instance.get(Calendar.YEAR);
            instance.set(year, Calendar.JANUARY, 1, 0, 0, 0);
            return instance.getTime();
        }
    
        /**
         * 获取两个日期之间的天数（两个字符串）
         * @param smdate
         * @param bdate
         * @return
         * @throws ParseException
         */
        public static int daysBetween(String smdate,String bdate) throws ParseException{
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
            Calendar cal = Calendar.getInstance();
            cal.setTime(sdf.parse(smdate));
            long time1 = cal.getTimeInMillis();
            cal.setTime(sdf.parse(bdate));
            long time2 = cal.getTimeInMillis();
            long between_days=(time2-time1)/(1000*3600*24);
            return Integer.parseInt(String.valueOf(between_days));
        }
    
        /**
         * 获取两个日期之间的天数（字符串与date）
         * @param smdate
         * @param bdate
         * @return
         * @throws ParseException
         */
        public static int daysBetween(String smdate,Date bdate) throws ParseException {
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
            Calendar cal = Calendar.getInstance();
            cal.setTime(sdf.parse(smdate));
            long time1 = cal.getTimeInMillis();
            cal.setTime(bdate);
            long time2 = cal.getTimeInMillis();
            long between_days=(time2-time1)/(1000*3600*24);
            return Integer.parseInt(String.valueOf(between_days));
        }
        /**
         * 获取两个日期之间的天数（字符串与date）
         * @param smdate
         * @param bdate
         * @return
         * @throws ParseException
         */
        public static int daysBetween(Date smdate, String bdate) throws ParseException {
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
            Calendar cal = Calendar.getInstance();
            cal.setTime(sdf.parse(bdate));
            long time1 = cal.getTimeInMillis();
            cal.setTime(smdate);
            long time2 = cal.getTimeInMillis();
            long between_days=(time1-time2)/(1000*3600*24);
            return Integer.parseInt(String.valueOf(between_days));
        }
    
        /**
         * 将毫秒转化（转换成*天*小时*分钟*秒）
         * @param millis
         * @return
         * @throws ParseException
         */
        public static String parse(long millis) throws ParseException {
            long days = millis / (1000 * 60 * 60 * 24);
            long hours = (millis % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60);
            long minutes = (millis % (1000 * 60 * 60)) / (1000 * 60);
            long  secs = (millis % (1000 * 60)) / (1000);
            String day = days==0l?"":days+"天";
            String hour = hours==0l?"":hours+"小时";
            String minute = minutes==0l?"":minutes+"分钟";
            String sec = secs==0l?"":secs+"秒";
            return day+hour+minute+sec;
        }
        public static void main(String[] args) {
            System.out.println(format(getFirstDateOfCurrentYear(), "yyyy-MM-dd HH:mm:ss"));
        }
    
    }