使用总结之Java项目中常用的日期和时间工具类

备份2018年海尔创客汇项目上用到的一些日期和时间处理的工具函数，以备不时之需。

直接贴代码

package com.hczt.haier.common.utils;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.time.DateUtils;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

/**
 * 精诚所至，金石为开。
 * 石の上にも三年;陽気の発する所金石亦透る。
 *
 * @Author mahaiqiang
 * @Create 2021/4/17 10:29 下午
 * @Desc TODO
 **/
public class DateUtil extends DateUtils {
    /**
     * yyyy-MM-dd
     */
    public final static String DATE_FORMAT    = "yyyy-MM-dd";
    /**
     * yyyy年MM月dd日
     */
    public final static String DATE_FORMAT_CN = "yyyy年MM月dd日";
    /**
     * yyyy-MM-dd HH:mm:ss
     */
    public final static String TIME_FORMAT    = "yyyy-MM-dd HH:mm:ss";

    /**
     * yyyy-MM-dd HH:mm
     */
    public final static String TIME_FORMAT_MINUTE = "yyyy-MM-dd HH:mm";

    /**
     * yyyy年MM月dd日 HH:mm:ss
     */
    public final static String TIME_FORMAT_CN        = "yyyy年MM月dd日 HH:mm:ss";
    /**
     * yyyy-MM
     */
    public final static String MONTH_FORMAT          = "yyyy-MM";
    /**
     * yyyyMMdd
     */
    public final static String DAY_FORMAT            = "yyyyMMdd";
    /**
     * yyyyMMddHHmmss
     */
    public final static String TIME_FORMAT_FOR_NAME  = "yyyyMMddHHmmss";
    /**
     * yyMMddHHmmss
     */
    public final static String TIME_FORMAT_FOR_SHORT = "yyMMddHHmmss";

    /**
     * yyyyMMddHHmmss
     */
    public final static String TIME_FORMAT_TIME = "yyyyMMddHHmmss";

    public static final long millisOfDay = 86400000L;

    public static Date formateData(Date date, String format) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        return sdf.parse(date2str(date, format));
    }

    public static Date str2date(String dateStr, String format) throws ParseException {
        if (StringUtils.isEmpty(dateStr)) {
            return null;
        }
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        return sdf.parse(dateStr);
    }

    public static String date2str(Date date, String format) {
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        return sdf.format(date);
    }

    /**
     * date format yyyy-MM-dd
     *
     * @param date
     * @return
     */
    public static String dateToSimpleDateFormat(Date date) {
        SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
        return sdf.format(date);
    }

    public static Date addDate(Date date, int addDay) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.add(Calendar.DAY_OF_YEAR, addDay);
        return c.getTime();
    }
    
    public static Date getOffsetDate(Date now, int field, int offset) {
        
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(now);
        
        calendar.add(field, offset);
        
        return calendar.getTime();
    }

    public static Date dayStartTime(Date date) throws ParseException {
        String dateStr = date2str(date, DATE_FORMAT);
        return str2date(dateStr, DATE_FORMAT);
    }


    /**
     * 获取某一天的最后一秒
     *
     * @param date
     * @return
     * @throws Exception
     */
    public static Date dayEndTime(Date date) throws ParseException {
        String dateStr = date2str(date, DATE_FORMAT);
        return str2date(dateStr + " 23:59:59", TIME_FORMAT);
    }

    /**
     * start
     * 本周开始时间戳 - 以星期一为本周的第一天
     */
    public static Date getThisMonday(Date date) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int day_of_week = cal.get(Calendar.DAY_OF_WEEK) - 1;
        if (day_of_week == 0) {
            day_of_week = 7;
        }
        cal.add(Calendar.DATE, -day_of_week + 1);
        return cal.getTime();
    }

    /**
     * 获取某时间段内所有的日期
     *
     * @return
     */
    public static List<Date> findDatesBetweenTwoDate(Date beginDate, Date endDate) throws ParseException {
        List<Date> dates = new LinkedList<>();
        if (!beginDate.after(endDate)) {
            beginDate = DateUtil.formateData(beginDate, DATE_FORMAT);
            endDate = DateUtil.formateData(endDate, DATE_FORMAT);
            dates.add(beginDate);
            Calendar calBegin = Calendar.getInstance();
            calBegin.setTime(beginDate);
            Calendar calEnd = Calendar.getInstance();
            calEnd.setTime(endDate);
            while (endDate.after(calBegin.getTime())) {
                calBegin.add(Calendar.DAY_OF_MONTH, 1);
                dates.add(calBegin.getTime());
            }
        }
        return dates;
    }


    /**
     * 获取某日期的前后的日期
     *
     * @param date         指定的日期
     * @param interval     间隔的时间 正为之后的日期，负为之前的日期
     * @param calendarUnit 间隔单位
     * @return
     */
    public static Date intervalOfDate(Date date, Integer interval, Integer calendarUnit) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.set(calendarUnit, calendar.get(calendarUnit) + interval);
        return calendar.getTime();
    }


    /**
     * 判断时间是不是今天
     * @param date
     * @return    是返回true，不是返回false
     */
    public static boolean isToday(Date date) {
        //当前时间
        Date now = new Date();
        SimpleDateFormat sf = new SimpleDateFormat("yyyyMMdd");
        //获取今天的日期
        String nowDay = sf.format(now);

        //对比的时间
        String day = sf.format(date);
        return day.equals(nowDay);
    }

    public static String formatDateTime(String startTime, String endTime) {
        String startDate = startTime.substring(0, 10);
        String endDate = endTime.substring(0, 10);
        String beginTime = startTime.substring(11, 19);
        String overTime = endTime.substring(11, 19);
        if (startDate.equals(endDate)) {
            return startDate + " " + beginTime + " ~ " + overTime;
        } else {
            return startDate + " " + beginTime + " ~ " + endDate + " " + overTime;
        }
    }

    public static void main(String[] args) {
        Date date = DateUtil.intervalOfDate(new Date(), -30, Calendar.MINUTE);
        System.out.println(DateUtil.date2str(date, DateUtil.TIME_FORMAT));
    }

    /**
     * 获取每天的开始时间 00:00:00:00
     *
     * @param date
     * @return
     */
    public static Date getStartTime(Date date) {
        Calendar dateStart = Calendar.getInstance();
        dateStart.setTime(date);
        dateStart.set(Calendar.HOUR_OF_DAY, 0);
        dateStart.set(Calendar.MINUTE, 0);
        dateStart.set(Calendar.SECOND, 0);
        return dateStart.getTime();
    }

    /**
     * 获取每天的开始时间 23:59:59:999
     *
     * @param date
     * @return
     */
    public static Date getEndTime(Date date) {
        Calendar dateEnd = Calendar.getInstance();
        dateEnd.setTime(date);
        dateEnd.set(Calendar.HOUR_OF_DAY, 23);
        dateEnd.set(Calendar.MINUTE, 59);
        dateEnd.set(Calendar.SECOND, 59);
        return dateEnd.getTime();
    }

    /**
     * 获取两个日期相隔天数
     *
     */
    public static Long daysBetweenDates(Date date1, Date date2) {
        long tmp1 = date1.getTime();
        long tmp2 = date2.getTime();
        return (tmp2 - tmp1) / millisOfDay;
    }

}