Java日期时间API系列13-----Jdk8中java.time包中的新的日期时间API类，时间类转换，Date转LocalDateTime，LocalDateTime转Date等

　　从前面的系列博客中可以看出Jdk8中java.time包中的新的日期时间API类设计的很好，但Date由于使用仍非常广泛，这就涉及到Date转LocalDateTime，LocalDateTime转Date。下面是时间类互相转换大全，包含Instant、LocalDate、LocalDateTime、LocalTime、ZonedDateTime和Date的相互转换，时间转换大全，下面是一个工具类，仅供参考：

具体包含：

LocalDateTime转Date,LocalDate转Date,LocalTime转Date,Instant转Date,epochMilli毫秒转Date,ZonedDateTime转Date,Date转LocalDateTime,LocalDate转LocalDateTime,LocalTime转LocalDateTime,Instant转LocalDateTime,epochMilli毫秒转LocalDateTime,temporal转LocalDateTime,ZonedDateTime转LocalDateTime,Date转LocalDate,LocalDateTime转LocalDate,Instant转LocalDate,temporal转LocalDate,ZonedDateTime转LocalDate,Date转LocalTime,LocalDateTime转LocalTime,Instant转LocalTime,temporal转LocalTime,ZonedDateTime转LocalTime,Date转Instant,LocalDateTime转Instant,LocalDate转Instant,LocalTime转Instant,epochMilli毫秒转Instant,temporal转Instant,ZonedDateTime转Instant,Date转毫秒值,LocalDateTime转毫秒值,LocalDate转毫秒值,Instant转毫秒值,ZonedDateTime转毫秒值,Date转ZonedDateTime,LocalDateTime转ZonedDateTime,LocalDate转ZonedDateTime,LocalTime转ZonedDateTime,Instant转ZonedDateTime,epochMilli毫秒转ZonedDateTime,temporal转ZonedDateTime.

package com.xkzhangsan.time.converter;

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.temporal.TemporalAccessor;
import java.util.Date;
import java.util.Objects;

/**
 * 日期转换
 * 包含Date、LocalDate、LocalDateTime、LocalTime、Instant和ZonedDateTime的互相转换
 *
 * 注意，ZonedDateTime相关的转换，尤其是其他时间转ZonedDateTime，要注意时间和对应时区一致。
* @ClassName: DateTimeConverterUtil
* @Description: DateTime Converter
* @author xkzhangsan
* @date 2019年12月1日
*
 */
public class DateTimeConverterUtil {

    private DateTimeConverterUtil(){
    }

    /**
     * LocalDateTime转Date
     * @param localDateTime
     * @return
     */
    public static Date toDate(LocalDateTime localDateTime) {
        Objects.requireNonNull(localDateTime, "localDateTime");
        return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
    }

    /**
     * LocalDate转Date
     * @param localDate
     * @return
     */
    public static Date toDate(LocalDate localDate) {
        Objects.requireNonNull(localDate, "localDate");
        return Date.from(localDate.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant());
    }

    /**
     * LocalTime转Date
     * 以当天的日期+LocalTime组成新的LocalDateTime转换为Date
     * @param localTime
     * @return
     */
    public static Date toDate(LocalTime localTime) {
        Objects.requireNonNull(localTime, "localTime");
        return Date.from(LocalDate.now().atTime(localTime).atZone(ZoneId.systemDefault()).toInstant());
    }    

    /**
     * Instant转Date
     * @param instant
     * @return
     */
    public static Date toDate(Instant instant) {
        return Date.from(instant);
    }

    /**
     * epochMilli毫秒转Date
     * @param epochMilli
     * @return
     */
    public static Date toDate(long epochMilli){
        Objects.requireNonNull(epochMilli, "epochMilli");
        return new Date(epochMilli);
    }

    /**
     * ZonedDateTime转Date
     * 注意时间对应的时区和默认时区差异
     * @param zonedDateTime
     * @return
     */
    public static Date toDate(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return Date.from(zonedDateTime.toInstant());
    }

    /**
     * Date转LocalDateTime
     * @param date
     * @return
     */
    public static LocalDateTime toLocalDateTime(Date date) {
        Objects.requireNonNull(date, "date");
        return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDateTime();
    }

    /**
     * LocalDate转LocalDateTime
     * @param localDate
     * @return
     */
    public static LocalDateTime toLocalDateTime(LocalDate localDate) {
        Objects.requireNonNull(localDate, "localDate");
        return localDate.atStartOfDay();
    }

    /**
     * LocalTime转LocalDateTime
     * 以当天的日期+LocalTime组成新的LocalDateTime
     * @param localTime
     * @return
     */
    public static LocalDateTime toLocalDateTime(LocalTime localTime) {
        Objects.requireNonNull(localTime, "localTime");
        return LocalDate.now().atTime(localTime);
    }

    /**
     * Instant转LocalDateTime
     * @param instant
     * @return
     */
    public static LocalDateTime toLocalDateTime(Instant instant) {
        return LocalDateTime.ofInstant(instant, ZoneId.systemDefault());
    }

    /**
     * epochMilli毫秒转LocalDateTime
     * @param epochMilli
     * @return
     */
    public static LocalDateTime toLocalDateTime(long epochMilli) {
        Objects.requireNonNull(epochMilli, "epochMilli");
        return LocalDateTime.ofInstant(Instant.ofEpochMilli(epochMilli), ZoneId.systemDefault());
    }

    /**
     * temporal转LocalDateTime
     * @param temporal
     * @return
     */
    public static LocalDateTime toLocalDateTime(TemporalAccessor temporal) {
        return LocalDateTime.from(temporal);
    }

    /**
     * ZonedDateTime转LocalDateTime
     * 注意时间对应的时区和默认时区差异
     * @param zonedDateTime
     * @return
     */
    public static LocalDateTime toLocalDateTime(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return zonedDateTime.toLocalDateTime();
    }

    /**
     * Date转LocalDate
     * @param date
     * @return
     */
    public static LocalDate toLocalDate(Date date) {
        return toLocalDateTime(date).toLocalDate();
    }

    /**
     * LocalDateTime转LocalDate
     * @param localDateTime
     * @return
     */
    public static LocalDate toLocalDate(LocalDateTime localDateTime) {
        Objects.requireNonNull(localDateTime, "localDateTime");
        return localDateTime.toLocalDate();
    }

    /**
     * Instant转LocalDate
     * @param instant
     * @return
     */
    public static LocalDate toLocalDate(Instant instant) {
        return toLocalDateTime(instant).toLocalDate();
    }

    /**
     * temporal转LocalDate
     * @param temporal
     * @return
     */
    public static LocalDate toLocalDate(TemporalAccessor temporal) {
        return LocalDate.from(temporal);
    }

    /**
     * ZonedDateTime转LocalDate
     * 注意时间对应的时区和默认时区差异
     * @param zonedDateTime
     * @return
     */
    public static LocalDate toLocalDate(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return zonedDateTime.toLocalDate();
    }

    /**
     * Date转LocalTime
     * @param date
     * @return
     */
    public static LocalTime toLocalTime(Date date) {
        return toLocalDateTime(date).toLocalTime();
    }

    /**
     * LocalDateTime转LocalTime
     * @param localDateTime
     * @return
     */
    public static LocalTime toLocalTime(LocalDateTime localDateTime) {
        Objects.requireNonNull(localDateTime, "localDateTime");
        return localDateTime.toLocalTime();
    }

    /**
     * Instant转LocalTime
     * @param instant
     * @return
     */
    public static LocalTime toLocalTime(Instant instant) {
        return toLocalDateTime(instant).toLocalTime();
    }

    /**
     * temporal转LocalTime
     * @param temporal
     * @return
     */
    public static LocalTime toLocalTime(TemporalAccessor temporal) {
        return LocalTime.from(temporal);
    }

    /**
     * ZonedDateTime转LocalTime
     * 注意时间对应的时区和默认时区差异
     * @param zonedDateTime
     * @return
     */
    public static LocalTime toLocalTime(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return zonedDateTime.toLocalTime();
    }

    /**
     * Date转Instant
     * @param date
     * @return
     */
    public static Instant toInstant(Date date) {
        Objects.requireNonNull(date, "date");
        return date.toInstant();
    }

    /**
     * LocalDateTime转Instant
     * @param localDateTime
     * @return
     */
    public static Instant toInstant(LocalDateTime localDateTime) {
        Objects.requireNonNull(localDateTime, "localDateTime");
        return localDateTime.atZone(ZoneId.systemDefault()).toInstant();
    }

    /**
     * LocalDate转Instant
     * @param localDate
     * @return
     */
    public static Instant toInstant(LocalDate localDate) {
        return toLocalDateTime(localDate).atZone(ZoneId.systemDefault()).toInstant();
    }

    /**
     * LocalTime转Instant
     * 以当天的日期+LocalTime组成新的LocalDateTime转换为Instant
     * @param localTime
     * @return
     */
    public static Instant toInstant(LocalTime localTime) {
        return toLocalDateTime(localTime).atZone(ZoneId.systemDefault()).toInstant();
    }

    /**
     * epochMilli毫秒转Instant
     * @param epochMilli
     * @return
     */
    public static Instant toInstant(long epochMilli) {
        Objects.requireNonNull(epochMilli, "epochMilli");
        return Instant.ofEpochMilli(epochMilli);
    }

    /**
     * temporal转Instant
     * @param temporal
     * @return
     */
    public static Instant toInstant(TemporalAccessor temporal) {
        return Instant.from(temporal);
    }

    /**
     * ZonedDateTime转Instant
     * 注意时间对应的时区和默认时区差异
     * @param zonedDateTime
     * @return
     */
    public static Instant toInstant(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return zonedDateTime.toInstant();
    }

    /**
     * Date转毫秒值
     * 从1970-01-01T00:00:00Z开始的毫秒值
     * @param date
     * @return
     */
    public static long toEpochMilli(Date date){
        Objects.requireNonNull(date, "date");
        return date.getTime();
    }

    /**
     * LocalDateTime转毫秒值
     * 从1970-01-01T00:00:00Z开始的毫秒值
     * @param localDateTime
     * @return
     */
    public static long toEpochMilli(LocalDateTime localDateTime){
        return toInstant(localDateTime).toEpochMilli();
    }

    /**
     * LocalDate转毫秒值
     * 从1970-01-01T00:00:00Z开始的毫秒值
     * @param localDate
     * @return
     */
    public static long toEpochMilli(LocalDate localDate){
        return toInstant(localDate).toEpochMilli();
    }

    /**
     * Instant转毫秒值
     * 从1970-01-01T00:00:00Z开始的毫秒值
     * @param instant
     * @return
     */
    public static long toEpochMilli(Instant instant){
        Objects.requireNonNull(instant, "instant");
        return instant.toEpochMilli();
    }

    /**
     * ZonedDateTime转毫秒值，注意时间对应的时区和默认时区差异
     * 从1970-01-01T00:00:00Z开始的毫秒值
     * @param zonedDateTime
     * @return
     */
    public static long toEpochMilli(ZonedDateTime zonedDateTime) {
        Objects.requireNonNull(zonedDateTime, "zonedDateTime");
        return zonedDateTime.toInstant().toEpochMilli();
    }

    /**
     * Date转ZonedDateTime，时区为系统默认时区
     * @param date
     * @return
     */
    public static ZonedDateTime toZonedDateTime(Date date) {
        Objects.requireNonNull(date, "date");
        return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDateTime()
                .atZone(ZoneId.systemDefault());
    }

    /**
     * LocalDateTime转ZonedDateTime，时区为系统默认时区
     * @param localDateTime
     * @return
     */
    public static ZonedDateTime toZonedDateTime(LocalDateTime localDateTime) {
        Objects.requireNonNull(localDateTime, "localDateTime");
        return localDateTime.atZone(ZoneId.systemDefault());
    }

/**
* LocalDateTime转ZonedDateTime，时区为zoneId对应时区
* 注意，需要保证localDateTime和zoneId是对应的，不然会出现错误
*
* @param localDateTime
* @param zoneId
* @return
*/
public static ZonedDateTime toZonedDateTime(LocalDateTime localDateTime, String zoneId) {
　　Objects.requireNonNull(localDateTime, "localDateTime");
　　Objects.requireNonNull(zoneId, "zoneId");
　　return localDateTime.atZone(ZoneId.of(zoneId));
}

/**
     * LocalDate转ZonedDateTime，时区为系统默认时区
     * @param localDate
     * @return such as 2020-02-19T00:00+08:00[Asia/Shanghai]
     */
    public static ZonedDateTime toZonedDateTime(LocalDate localDate) {
        Objects.requireNonNull(localDate, "localDate");
        return localDate.atStartOfDay().atZone(ZoneId.systemDefault());
    }

    /**
     * LocalTime转ZonedDateTime
     * 以当天的日期+LocalTime组成新的ZonedDateTime，时区为系统默认时区
     * @param localTime
     * @return
     */
    public static ZonedDateTime toZonedDateTime(LocalTime localTime) {
        Objects.requireNonNull(localTime, "localTime");
        return LocalDate.now().atTime(localTime).atZone(ZoneId.systemDefault());
    }

    /**
     * Instant转ZonedDateTime，时区为系统默认时区
     * @param instant
     * @return
     */
    public static ZonedDateTime toZonedDateTime(Instant instant) {
        return LocalDateTime.ofInstant(instant, ZoneId.systemDefault()).atZone(ZoneId.systemDefault());
    }

    /**
     * epochMilli毫秒转ZonedDateTime，时区为系统默认时区
     * @param epochMilli
     * @return
     */
    public static ZonedDateTime toZonedDateTime(long epochMilli) {
        Objects.requireNonNull(epochMilli, "epochMilli");
        return LocalDateTime.ofInstant(Instant.ofEpochMilli(epochMilli), ZoneId.systemDefault())
                .atZone(ZoneId.systemDefault());
    }

    /**
     * temporal转ZonedDateTime，时区为系统默认时区
     * @param temporal
     * @return
     */
    public static ZonedDateTime toZonedDateTime(TemporalAccessor temporal) {
        return LocalDateTime.from(temporal).atZone(ZoneId.systemDefault());
    }    

}

测试代码

package com.xkzhangsan.time.test;

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZonedDateTime;
import java.util.Date;

import org.junit.Test;

import com.xkzhangsan.time.converter.DateTimeConverterUtil;

public class ConverterTest {

    @Test
    public void dateConverterTest(){
        System.out.println("===================dateConverterTest=====================");
        Date date = new Date();
        System.out.println(DateTimeConverterUtil.toLocalDateTime(date));
        System.out.println(DateTimeConverterUtil.toLocalDate(date));
        System.out.println(DateTimeConverterUtil.toLocalTime(date));
        System.out.println(DateTimeConverterUtil.toInstant(date));
    }

    @Test
    public void localDateTimeConverterTest(){
        System.out.println("===================localDateTimeConverterTest=====================");
        LocalDateTime ldt = LocalDateTime.now();
        System.out.println(ldt);
        System.out.println(DateTimeConverterUtil.toDate(ldt));
        System.out.println(DateTimeConverterUtil.toLocalDate(ldt));
        System.out.println(DateTimeConverterUtil.toLocalTime(ldt));
        System.out.println(DateTimeConverterUtil.toInstant(ldt));
        System.out.println(DateTimeConverterUtil.toZonedDateTime(ldt));
    }

    @Test
    public void localDateConverterTest(){
        System.out.println("===================localDateConverterTest=====================");
        LocalDate ld = LocalDate.now();
        System.out.println(ld);
        System.out.println(DateTimeConverterUtil.toDate(ld));
        System.out.println(DateTimeConverterUtil.toLocalDateTime(ld));
        System.out.println(DateTimeConverterUtil.toInstant(ld));
    }

    @Test
    public void localTimeConverterTest(){
        System.out.println("===================localTimeConverterTest=====================");
        LocalTime lt = LocalTime.now();
        System.out.println(lt);
        System.out.println(DateTimeConverterUtil.toDate(lt));
        System.out.println(DateTimeConverterUtil.toLocalDateTime(lt));
        System.out.println(DateTimeConverterUtil.toLocalTime(lt));
        System.out.println(DateTimeConverterUtil.toInstant(lt));
    }    

    @Test
    public void instantConverterTest(){
        System.out.println("===================instantConverterTest=====================");
        Instant instant = Instant.now();
        System.out.println(instant);
        System.out.println(DateTimeConverterUtil.toDate(instant));
        System.out.println(DateTimeConverterUtil.toLocalDateTime(instant));
        System.out.println(DateTimeConverterUtil.toLocalDate(instant));
    }

    @Test
    public void zonedDateTimeConverterTest(){
        System.out.println("===================zonedDateTimeConverterTest=====================");
        System.out.println("===================ToOther=====================");
        ZonedDateTime zonedDateTime = ZonedDateTime.now();
        System.out.println(zonedDateTime);
        System.out.println(DateTimeConverterUtil.toDate(zonedDateTime));
        System.out.println(DateTimeConverterUtil.toLocalDateTime(zonedDateTime));
        System.out.println(DateTimeConverterUtil.toLocalDate(zonedDateTime));
        System.out.println(DateTimeConverterUtil.toLocalTime(zonedDateTime));
        System.out.println(DateTimeConverterUtil.toInstant(zonedDateTime));
        System.out.println("===================toZonedDateTime=====================");
        System.out.println(zonedDateTime);
        System.out.println(DateTimeConverterUtil.toZonedDateTime(new Date()));
        System.out.println(DateTimeConverterUtil.toZonedDateTime(LocalDateTime.now()));
        System.out.println(DateTimeConverterUtil.toZonedDateTime(LocalDate.now()));
        System.out.println(DateTimeConverterUtil.toZonedDateTime(LocalTime.now()));
        System.out.println(DateTimeConverterUtil.toZonedDateTime(Instant.now()));
    }
}

输出：

===================dateConverterTest=====================
2020-02-19T16:10:04.366
2020-02-19
16:10:04.366
2020-02-19T08:10:04.366Z
===================localTimeConverterTest=====================
16:10:04.458
Wed Feb 19 16:10:04 CST 2020
2020-02-19T16:10:04.458
16:10:04.458
2020-02-19T08:10:04.458Z
===================localDateConverterTest=====================
2020-02-19
Wed Feb 19 00:00:00 CST 2020
2020-02-19T00:00
2020-02-18T16:00:00Z
===================zonedDateTimeConverterTest=====================
===================ToOther=====================
2020-02-19T16:10:04.464+08:00[Asia/Shanghai]
Wed Feb 19 16:10:04 CST 2020
2020-02-19T16:10:04.464
2020-02-19
16:10:04.464
2020-02-19T08:10:04.464Z
===================toZonedDateTime=====================
2020-02-19T16:10:04.464+08:00[Asia/Shanghai]
2020-02-19T16:10:04.465+08:00[Asia/Shanghai]
2020-02-19T16:10:04.465+08:00[Asia/Shanghai]
2020-02-19T00:00+08:00[Asia/Shanghai]
2020-02-19T16:10:04.466+08:00[Asia/Shanghai]
2020-02-19T16:10:04.466+08:00[Asia/Shanghai]
===================localDateTimeConverterTest=====================
2020-02-19T16:10:04.466
Wed Feb 19 16:10:04 CST 2020
2020-02-19
16:10:04.466
2020-02-19T08:10:04.466Z
2020-02-19T16:10:04.466+08:00[Asia/Shanghai]
===================instantConverterTest=====================
2020-02-19T08:10:04.467Z
Wed Feb 19 16:10:04 CST 2020
2020-02-19T16:10:04.467
2020-02-19

源码地址：https://github.com/xkzhangsan/xk-time