mjava-1/mjava/src/main/java/com/malk/Util/UtilDateTime.java

package com.malk.Util;

import cn.hutool.core.util.ObjectUtil;
import lombok.SneakyThrows;
import org.apache.commons.lang3.StringUtils;

import javax.annotation.Nullable;
import java.text.SimpleDateFormat;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjusters;
import java.util.Date;

/**
 * 时间格式 [Calendar 日历类, Date 是java 8前产物, LocalDateTime]
 */
public abstract class UtilDateTime {

    public final static String DATE_PATTERN = "yyyy-MM-dd";
    public final static String TIME_PATTERN = "HH:mm:ss";
    public final static String DATE_TIME_PATTERN = "yyyy-MM-dd HH:mm:ss";

    /// T表示分隔符，Z表示的是UTC "yyyy-MM-dd'T'HH:mm:ss.SSS Z"

    //// convert ////

    // 将java.util.Date 转换为java8 的java.time.LocalDateTime,默认时区为东8区
    public static LocalDateTime convertToLocalDateTimeFromDate(Date date) {
        return date.toInstant().atOffset(ZoneOffset.of("+8")).toLocalDateTime();
    }

    // 将java8 的 java.time.LocalDateTime 转换为 java.util.Date，默认时区为东8区
    public static Date convertToDateFromLocalDateTime(LocalDateTime localDateTime) {
        return Date.from(localDateTime.toInstant(ZoneOffset.of("+8")));
    }

    // 获取时间段内小时
    public static float betweenHour(Temporal startInclusive, Temporal endExclusive) {
        return Duration.between(startInclusive, endExclusive).toMillis() / 60f;
    }

    // 获取上月第一天0点
    public static LocalDateTime firstDayOfLastMonth(LocalDateTime dateTime) {
        int month = dateTime.getMonthValue() - 1;
        int year = dateTime.getYear();
        if (month == 0) {
            month = 12;
        }
        return LocalDateTime.of(year, month, 1, 0, 0, 0);
    }

    // 计算时间差和指定如一月最后一天很方便, 如下个月第一天 .... [时间会保留传入时间]
    public static LocalDateTime firstDayOfNextMonth(LocalDateTime dateTime) {
        return dateTime.with(TemporalAdjusters.firstDayOfNextMonth());
    }

    // 获取当天0点时间
    public static LocalDateTime minLocalDateTime(@Nullable LocalDateTime dateTime) {
        return LocalDateTime.of(dateTime.toLocalDate(), LocalTime.MIN);
    }

    //// Date  ////

    public static String formatDateTime(Date dateTime) {
        if (ObjectUtil.isNull(dateTime)) return "";
        return new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS Z").format(dateTime);
    }

    public static String formatDate(Date dateTime) {
        return new SimpleDateFormat(DATE_PATTERN).format(dateTime);
    }

    public static String formatTime(Date dateTime) {
        return new SimpleDateFormat(TIME_PATTERN).format(dateTime);
    }

    @SneakyThrows
    public static Date parseDateTime(String dateStr) {
        if (StringUtils.isBlank(dateStr)) {
            return new Date();
        }
        return new SimpleDateFormat(DATE_TIME_PATTERN).parse(dateStr);
    }

    @SneakyThrows
    public static Date parseDate(String dateStr) {
        return new SimpleDateFormat(DATE_PATTERN).parse(dateStr);
    }

    @SneakyThrows
    public static Date parseTime(String dateStr) {
        return new SimpleDateFormat(TIME_PATTERN).parse(dateStr);
    }


    //// LocalDateTime ////

    public static String formatLocalDateTime(LocalDateTime dateTime) {
        if (ObjectUtil.isNull(dateTime)) return "";
        return DateTimeFormatter.ofPattern(DATE_TIME_PATTERN).format(dateTime);
    }

    public static String formatLocalDate(LocalDate dateTime) {
        return DateTimeFormatter.ofPattern(DATE_PATTERN).format(dateTime);
    }

    public static String formatLocalTime(LocalTime dateTime) {
        return DateTimeFormatter.ofPattern(TIME_PATTERN).format(dateTime);
    }

    public static LocalDateTime parseLocalDateTime(String dateStr) {
        if (StringUtils.isBlank(dateStr)) {
            return LocalDateTime.now();
        }
        return LocalDateTime.parse(dateStr, DateTimeFormatter.ofPattern(DATE_TIME_PATTERN));
    }

    public static LocalDate parseLocalDate(String dateStr) {
        return LocalDate.parse(dateStr, DateTimeFormatter.ofPattern(DATE_PATTERN));
    }

    public static LocalTime parseLocalTime(String dateStr) {
        return LocalTime.parse(dateStr, DateTimeFormatter.ofPattern(TIME_PATTERN));
    }
}