日期工具类 - 操作字符串和 Date、LocalDate 互转，两个日期的时间差等

2022-11-20
浙江
本文字数：4022 字
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避免重复造轮子，相关方法基于 hutool 日期时间工具封装并做部分增强。需要先引入如下坐标

          <dependency>              <groupId>cn.hutool</groupId>              <artifactId>hutool-all</artifactId>              <version>${hutool.version}</version>          </dependency>

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字符串转 Date

    //字符串转Date    Date dateTime = DateUtil.parseDate("2022-04-06");    System.out.println(dateTime);

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Date 转字符串

//Date转字符串不指定format格式，默认yyyy-MM-dd HH:mm:ssString dateStr = DateUtil.date2Str(new Date());System.out.println(dateStr);//Date转字符串指定格式String dateStr2 = DateUtil.date2Str("yyyy/MM/dd",new Date());System.out.println(dateStr2);

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字符串转 LocalDate

//字符串转LocalDateLocalDate localDate = DateUtil.parseLocalDate("2022-04-06");System.out.println(localDate);

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Date 转 LocalDate

//Date转LocalDateLocalDate localDate = DateUtil.date2LocalDate(new Date());System.out.println(localDate);

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LocalDate 转字符串

//LocalDate转StrString localDateStr = DateUtil.localDate2Str(LocalDate.now());System.out.println(localDateStr);

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两个日期的时间差

String beginDateStr = "2022-02-01 22:33:23";Date beginDate = DateUtil.parse(beginDateStr);
String endDateStr = "2022-03-10 23:33:23";Date endDate = DateUtil.parse(endDateStr);//相差天数(37)long betweenDay = DateUtil.between(beginDate, endDate, DateUnit.DAY);System.out.println(betweenDay);//格式化时间差(37天1小时)String formatBetween = DateUtil.formatBetween(beginDate, endDate, BetweenFormater.Level.HOUR);System.out.println(formatBetween);

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一天的开始和结束时间

String dateStr = "2022-04-07 10:33:23";Date date = DateUtil.parse(dateStr);
//一天的开始时间：2022-04-07 00:00:00Date beginOfDay = DateUtil.beginOfDay(date);System.out.println(beginOfDay);
//一天的结束时间：2022-04-07 23:59:59Date endOfDay = DateUtil.endOfDay(date);System.out.println(endOfDay);

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工具类如下：

/** * <p>基于hutool的日期工具类增强</p> * * @author zjq * @date 2021/04/07 */public class DateUtil extends cn.hutool.core.date.DateUtil {
    private static final String[] PARSE_PATTERNS = {            "yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss", "yyyy-MM-dd HH:mm", "yyyy-MM",            "yyyy/MM/dd", "yyyy/MM/dd HH:mm:ss", "yyyy/MM/dd HH:mm", "yyyy/MM",            "yyyy.MM.dd", "yyyy.MM.dd HH:mm:ss", "yyyy.MM.dd HH:mm", "yyyy.MM"};
    public static final DateTimeFormatter TIME_FORMATTER = DateTimeFormatter.ofPattern("HH:mm:ss");    public static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd");    public static final DateTimeFormatter DATETIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    /**     * 字符串转date类型     *     * @param dateStr     * @return     */    public static Date parseDate(Object dateStr) {        if (ObjectUtils.isNull(dateStr)) {            return null;        }        if (dateStr instanceof Double) {            return org.apache.poi.ss.usermodel.DateUtil.getJavaDate((Double) dateStr);        }        return parse(dateStr.toString(), PARSE_PATTERNS);    }
    /**     * Date类型转字符串     *     * @param date     * @return yyyy-MM-dd HH:mm:ss     */    public static String date2Str(Date date) {        return date2Str(null, date);    }
    /**     * Date类型转字符串     *     * @param format     * @param date     * @return     */    public static String date2Str(String format, Date date) {        if (ObjectUtils.isNull(date)) {            return null;        }        SimpleDateFormat dateFormat = StrUtil.isNotBlank(format) ?new SimpleDateFormat(format):                new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");        return dateFormat.format(date);    }
    /**     * 字符串转LocalTime类型     *     * @param dateStr     * @return     */    public static LocalTime parseLocalTime(Object dateStr) {        if (ObjectUtils.isNull(dateStr)) {            return null;        }        if (dateStr instanceof Double) {            return date2LocalTime(parseDate(dateStr));        }        return LocalTime.parse(dateStr.toString(), TIME_FORMATTER);    }
    /**     * Date转LocalTime     *     * @param date     * @return     */    public static LocalTime date2LocalTime(Date date) {        if (null == date) {            return null;        }        return date.toInstant().atZone(ZoneId.systemDefault()).toLocalTime();    }
    /**     * LocalTime转Str     *     * @param localTime     * @return HH:mm:ss     */    public static String localTime2Str(LocalTime localTime) {        return localTime2Str(null, localTime);    }
    /**     * LocalTime转str     *     * @param format    格式     * @param localTime     * @return     */    public static String localTime2Str(String format, LocalTime localTime) {        if (null == localTime) {            return null;        }        DateTimeFormatter formatter = StrUtil.isBlank(format) ?                TIME_FORMATTER : DateTimeFormatter.ofPattern(format);        return localTime.format(formatter);    }
    /**     * 字符串转LocalDate类型     *     * @param dateStr     * @return     */    public static LocalDate parseLocalDate(Object dateStr) {        if (ObjectUtils.isNull(dateStr)) {            return null;        }        if (dateStr instanceof Double) {            return date2LocalDate(parseDate(dateStr));        }        return LocalDate.parse(dateStr.toString(), DATE_FORMATTER);    }
    /**     * Date转LocalDate     *     * @param date     * @return     */    public static LocalDate date2LocalDate(Date date) {        if (null == date) {            return null;        }        return date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();    }
    /**     * LocalDate转Str     *     * @param localDate     * @return     */    public static String localDate2Str(LocalDate localDate) {        return localDate2Str(null, localDate);    }
    /**     * LocalDate转Str     *     * @param format    格式     * @param localDate     * @return     */    public static String localDate2Str(String format, LocalDate localDate) {        if (null == localDate) {            return null;        }        DateTimeFormatter formatter = StrUtil.isBlank(format) ?                DATE_FORMATTER : DateTimeFormatter.ofPattern(format);        return localDate.format(formatter);    }
    /**     * 字符串转LocalDateTime类型     *     * @param dateStr     * @return     */    public static LocalDateTime parseLocalDateTime(Object dateStr) {        if (ObjectUtils.isNull(dateStr)) {            return null;        }        if (dateStr instanceof Double) {            return date2LocalDateTime(parseDate(dateStr));        }        return LocalDateTime.parse(dateStr.toString(), DATETIME_FORMATTER);    }
    /**     * Date转LocalDateTime     *     * @param date     * @return     */    public static LocalDateTime date2LocalDateTime(Date date) {        if (null == date) {            return null;        }        return date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();    }
    /**     * LocalDate转Str     *     * @param localDateTime     * @return     */    public static String localDateTime2Str(LocalDateTime localDateTime) {        return localDateTime2Str(null, localDateTime);    }
    /**     * LocalDate转Str     *     * @param format     * @param localDateTime     * @return     */    public static String localDateTime2Str(String format, LocalDateTime localDateTime) {        if (null == localDateTime) {            return null;        }        DateTimeFormatter formatter = StrUtil.isBlank(format) ?                DATETIME_FORMATTER : DateTimeFormatter.ofPattern(format);        return localDateTime.format(formatter);    }}