java获取当日、本周、本月、本年

1、使用 LocalDateTime

最后的格式需要自己转换一下

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.temporal.TemporalAdjusters;
 
public class DateUtils {
 
    public static void main(String[] args) {
        LocalDate today = LocalDate.now();
        LocalDate firstDayOfMonth = today.with(TemporalAdjusters.firstDayOfMonth());
        LocalDate lastDayOfMonth = today.with(TemporalAdjusters.lastDayOfMonth());
        LocalDate firstDayOfYear = today.withDayOfYear(1);
        LocalDate lastDayOfYear = today.withDayOfYear(today.lengthOfYear());
 
        // 当日
        LocalDateTime startOfDay = LocalDateTime.of(today, LocalTime.MIN);
        LocalDateTime endOfDay = LocalDateTime.of(today, LocalTime.MAX);
 
        // 本周（周一到周日）
        LocalDate startOfWeek = today.with(TemporalAdjusters.previousOrSame(java.time.DayOfWeek.MONDAY));
        LocalDate endOfWeek = today.with(TemporalAdjusters.nextOrSame(java.time.DayOfWeek.SUNDAY));
        LocalDateTime startOfWeekDateTime = LocalDateTime.of(startOfWeek, LocalTime.MIN);
        LocalDateTime endOfWeekDateTime = LocalDateTime.of(endOfWeek, LocalTime.MAX);
 
        // 本月
        LocalDateTime startOfMonth = LocalDateTime.of(firstDayOfMonth, LocalTime.MIN);
        LocalDateTime endOfMonth = LocalDateTime.of(lastDayOfMonth, LocalTime.MAX);
 
        // 本年
        LocalDateTime startOfYear = LocalDateTime.of(firstDayOfYear, LocalTime.MIN);
        LocalDateTime endOfYear = LocalDateTime.of(lastDayOfYear, LocalTime.MAX);
 
        // 打印结果
        System.out.println("当日开始时间: " + startOfDay);
        System.out.println("当日结束时间: " + endOfDay);
        System.out.println("本周开始时间: " + startOfWeekDateTime);
        System.out.println("本周结束时间: " + endOfWeekDateTime);
        System.out.println("本月开始时间: " + startOfMonth);
        System.out.println("本月结束时间: " + endOfMonth);
        System.out.println("本年开始时间: " + startOfYear);
        System.out.println("本年结束时间: " + endOfYear);
    }
}

2、使用 Calendar

import java.sql.Timestamp;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class DateUtil {
    /**
     * 获取当天开始时间
     *
     * @return
     */
    public static Date getDayBegin() {
        Calendar cal = Calendar.getInstance();
        //0点
        cal.set(Calendar.HOUR_OF_DAY, 0);
        //0分
        cal.set(Calendar.MINUTE, 0);
        //0秒
        cal.set(Calendar.SECOND, 0);
        //0毫秒
        cal.set(Calendar.MILLISECOND, 0);
        return cal.getTime();
    }

    /**
     * 获取当天结束时间
     *
     * @return
     */
    public static Date getDayEnd() {
        Calendar cal = Calendar.getInstance();
        //23点
        cal.set(Calendar.HOUR_OF_DAY, 23);
        //59分
        cal.set(Calendar.MINUTE, 59);
        //59秒
        cal.set(Calendar.SECOND, 59);
        return cal.getTime();
    }

    /**
     * 获取昨天开始时间
     *
     * @return
     */
    public static Date getBeginDayOfYesterday() {
        Calendar cal = Calendar.getInstance();
        //当天开始时间
        cal.setTime(getDayBegin());
        //当天月份天数减1
        cal.add(Calendar.DAY_OF_MONTH, -1);
        return cal.getTime();
    }

    /**
     * 获取昨天结束时间
     *
     * @return
     */
    public static Date getEndDayOfYesterday() {
        Calendar cal = Calendar.getInstance();
        //当天结束时间
        cal.setTime(getDayEnd());
        //当天月份天数减1
        cal.add(Calendar.DAY_OF_MONTH, -1);
        return cal.getTime();
    }

    /**
     * 获取明天开始时间
     *
     * @return
     */
    public static Date getBeginDayOfTomorrow() {
        Calendar cal = Calendar.getInstance();
        //当天开始时间
        cal.setTime(getDayBegin());
        //当天月份天数加1
        cal.add(Calendar.DAY_OF_MONTH, 1);
        return cal.getTime();
    }

    /**
     * 获取明天结束时间
     *
     * @return
     */
    public static Date getEndDayOfTomorrow() {
        Calendar cal = Calendar.getInstance();
        //当天结束时间
        cal.setTime(getDayEnd());
        //当天月份天数加1
        cal.add(Calendar.DAY_OF_MONTH, 1);
        return cal.getTime();
    }

    /**
     * 获取某个日期的开始时间
     *
     * @param d
     * @return
     */
    public static Timestamp getDayStartTime(Date d) {
        Calendar calendar = Calendar.getInstance();
        if (null != d) {
            calendar.setTime(d);
        }
        calendar.set(calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        return new Timestamp(calendar.getTimeInMillis());
    }

    /**
     * 获取某个日期的结束时间
     *
     * @param d
     * @return
     */
    public static Timestamp getDayEndTime(Date d) {
        Calendar calendar = Calendar.getInstance();
        if (null != d) {
            calendar.setTime(d);
        }
        calendar.set(calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 23, 59, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        return new Timestamp(calendar.getTimeInMillis());
    }

    /**
     * 获取本周的开始时间
     *
     * @return
     */
    public static Date getBeginDayOfWeek() {
        Date date = new Date();
        if (date == null) {
            return null;
        }
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == 1) {
            dayOfWeek += 7;
        }
        cal.add(Calendar.DATE, 2 - dayOfWeek);
        return getDayStartTime(cal.getTime());
    }

    /**
     * 获取本周的结束时间
     *
     * @return
     */
    public static Date getEndDayOfWeek() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(getBeginDayOfWeek());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        Date weekEndSta = cal.getTime();
        return getDayEndTime(weekEndSta);
    }

    /**
     * 获取上周开始时间
     */
    @SuppressWarnings("unused")
    public static Date getBeginDayOfLastWeek() {
        Date date = new Date();
        if (date == null) {
            return null;
        }
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
        if (dayofweek == 1) {
            dayofweek += 7;
        }
        cal.add(Calendar.DATE, 2 - dayofweek - 7);
        return getDayStartTime(cal.getTime());
    }

    /**
     * 获取上周的结束时间
     *
     * @return
     */
    public static Date getEndDayOfLastWeek() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(getBeginDayOfLastWeek());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        Date weekEndSta = cal.getTime();
        return getDayEndTime(weekEndSta);
    }

    /**
     * 获取今年是哪一年
     *
     * @return
     */
    public static Integer getNowYear() {
        Date date = new Date();
        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
        gc.setTime(date);
        return Integer.valueOf(gc.get(1));
    }

    /**
     * 获取本月是哪一月
     *
     * @return
     */
    public static int getNowMonth() {
        Date date = new Date();
        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
        gc.setTime(date);
        return gc.get(2) + 1;
    }

    /**
     * 获取本月的开始时间
     *
     * @return
     */
    public static Date getBeginDayOfMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 1, 1);
        return getDayStartTime(calendar.getTime());
    }

    /**
     * 获取本月的结束时间
     *
     * @return
     */
    public static Date getEndDayOfMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 1, 1);
        int day = calendar.getActualMaximum(5);
        calendar.set(getNowYear(), getNowMonth() - 1, day);
        return getDayEndTime(calendar.getTime());
    }

    /**
     * 获取上月的开始时间
     *
     * @return
     */
    public static Date getBeginDayOfLastMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 2, 1);
        return getDayStartTime(calendar.getTime());
    }

    /**
     * 获取上月的结束时间
     *
     * @return
     */
    public static Date getEndDayOfLastMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 2, 1);
        int day = calendar.getActualMaximum(5);
        calendar.set(getNowYear(), getNowMonth() - 2, day);
        return getDayEndTime(calendar.getTime());
    }

    /**
     * 获取本年的开始时间
     *
     * @return
     */
    public static Date getBeginDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, getNowYear());
        cal.set(Calendar.MONTH, Calendar.JANUARY);
        cal.set(Calendar.DATE, 1);
        return getDayStartTime(cal.getTime());
    }

    /**
     * 获取本年的结束时间
     *
     * @return
     */
    public static Date getEndDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, getNowYear());
        cal.set(Calendar.MONTH, Calendar.DECEMBER);
        cal.set(Calendar.DATE, 31);
        return getDayEndTime(cal.getTime());
    }
}