Java获取某天、某月或某年的开始结束日期或开始结束时间戳

 
@Slf4j
public class DateTimeUtil {
    /**
     * 默认日期格式
     */
    public static String DEFAULT_FORMAT = "yyyy-MM-dd";
 
    /**
     * 获取上一年年份
     *
     * @return
     */
    public static Integer getLastYear() {
        SimpleDateFormat formats = new SimpleDateFormat("yyyy");
        Calendar c = Calendar.getInstance();
        c.add(Calendar.YEAR, -1);
        Date date = c.getTime();
        // Date类型转String类型
        String format = formats.format(date);
        // String类型转int类型
        int parseInt = Integer.parseInt(format);
        log.info("去年为{}年", parseInt);
        return parseInt;
    }
 
    /**
     * 格式化日期
     *
     * @param date 日期对象
     * @return String 日期字符串
     */
    public static String formatDate(Date date) {
        SimpleDateFormat f = new SimpleDateFormat(DEFAULT_FORMAT);
        return f.format(date);
    }
 
    /**
     * 获取当年的第一天
     *
     * @param
     * @return
     */
    public static Date getCurrYearFirst() {
        Calendar currCal = Calendar.getInstance();
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearFirst(currentYear);
    }
 
    /**
     * 获取当年的最后一天
     *
     * @param
     * @return
     */
    public static Date getCurrYearLast() {
        Calendar currCal = Calendar.getInstance();
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearLast(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();
        String nowTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(currYearFirst);
        log.info("去年第一天为{}", nowTime);
        return currYearFirst;
    }
 
    /**
     * 获取某年最后一天日期
     *
     * @param year 年份
     * @return Date
     */
    public static Date getYearLast(int year) {
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        calendar.roll(Calendar.DAY_OF_YEAR, -1);
        return calendar.getTime();
    }
 
    /**
     * 获取指定某一天的开始时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param timeZone  如 GMT+8:00
     * @return
     */
    public static Long getDailyStartTime(Long timeStamp, String timeZone) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeZone(TimeZone.getTimeZone(timeZone));
        calendar.setTimeInMillis(timeStamp);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        return calendar.getTimeInMillis();
    }
 
    /**
     * 获取指定某一天的结束时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param timeZone  如 GMT+8:00
     * @return
     */
    public static Long getDailyEndTime(Long timeStamp, String timeZone) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeZone(TimeZone.getTimeZone(timeZone));
        calendar.setTimeInMillis(timeStamp);
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        return calendar.getTimeInMillis();
    }
 
    /**
     * 获取当月开始时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param timeZone  如 GMT+8:00
     * @return
     */
    public static Long getMonthStartTime(Long timeStamp, String timeZone) {
        Calendar calendar = Calendar.getInstance();// 获取当前日期
        calendar.setTimeZone(TimeZone.getTimeZone(timeZone));
        calendar.setTimeInMillis(timeStamp);
        calendar.add(Calendar.YEAR, 0);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, 1);// 设置为1号,当前日期既为本月第一天
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        return calendar.getTimeInMillis();
    }
 
    /**
     * 获取当月的结束时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param timeZone  如 GMT+8:00
     * @return
     */
    public static Long getMonthEndTime(Long timeStamp, String timeZone) {
        Calendar calendar = Calendar.getInstance();// 获取当前日期
        calendar.setTimeZone(TimeZone.getTimeZone(timeZone));
        calendar.setTimeInMillis(timeStamp);
        calendar.add(Calendar.YEAR, 0);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));// 获取当前月最后一天
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        return calendar.getTimeInMillis();
    }
 
    /**
     * 获取当年的开始时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param "GMT+8:00"  如 GMT+8:00
     * @return
     */
    public static Long getYearStartTime(Long timeStamp) {
        Calendar calendar = Calendar.getInstance();// 获取当前日期
        calendar.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        calendar.setTimeInMillis(timeStamp);
        calendar.add(Calendar.YEAR, 0);
        calendar.add(Calendar.DATE, 0);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_YEAR, 1);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        return calendar.getTimeInMillis();
    }
 
    /**
     * 获取当年的最后时间戳
     *
     * @param timeStamp 毫秒级时间戳
     * @param "GMT+8:00"  如 GMT+8:00
     * @return
     */
    public static Long getYearEndTime(Long timeStamp) {
        Calendar calendar = Calendar.getInstance();// 获取当前日期
        calendar.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        calendar.setTimeInMillis(timeStamp);
        int year = calendar.get(Calendar.YEAR);
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        calendar.roll(Calendar.DAY_OF_YEAR, -1);
        return calendar.getTimeInMillis();
    }
    /**
     * 获取当天的开始时间和结束时间
     */
    public static void main(String[] args) {
        Date yearFirst = getYearFirst(2023);
        System.out.println("今年第一天：" + yearFirst.getTime());
        Date yearLast = getYearLast(2023);
        System.out.println("今年最后一天：" + yearLast.getTime());
        // 获取当天开始时间-00:00:00
        LocalDateTime todayStart = LocalDateTime.of(LocalDate.now(), LocalTime.MIN);
        String todayStartStr = todayStart.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
        // 获取当天结束时间-23:59:59
        LocalDateTime todayEnd = LocalDateTime.of(LocalDate.now(), LocalTime.MAX);
        String todayEndStr = todayEnd.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
 
    }
 
}