LocalDateTime、LocalDate、Date的相互转换(亲测LocalDateTime转LocalDate)

骑猪看日落 2023-10-03 08:56 37阅读 0赞

来源：[https://www.cnblogs.com/CF1314/p/13884530.html][https_www.cnblogs.com_CF1314_p_13884530.html]

**目录**

*  [LocalDateTime、LocalDate、Date的相互转换][LocalDateTime_LocalDate_Date]
    
     *  [LocalDateTime 转 LocalDate][LocalDateTime _ LocalDate]
     *  [LocalDateTime 转 Date][LocalDateTime _ Date]
     *  [LocalDate 转 LocalDateTime][LocalDate _ LocalDateTime]
     *  [LocalDate 转 Date][LocalDate _ Date]
     *  [Date 转 LocalDateTime][Date _ LocalDateTime]
     *  [Date 转 LocalDate][Date _ LocalDate]

--------------------

[回到顶部][Link 1]

### LocalDateTime、LocalDate、Date的相互转换 ###

LocalDateTime 及 LocalDate 是 Java8 的新特性，有时为了兼容 Date 类型需要进行转换。

#### LocalDateTime 转 LocalDate ####

直接调用 toLocalDate() 方法

LocalDateTime localDateTime = LocalDateTime.now();
    LocalDate localDate = localDateTime.toLocalDate();

#### LocalDateTime 转 Date ####

在LocalDateTime 转 Date 时，需要使用到 Java 8的几个类

*  ZoneId/ZoneOffset：表示时区
 *  ZonedDateTime： 表示特定时区的日期和时间
 *  Instant：表示时刻，不直接对应年月日信息，需要通过时区转换

LocalDateTime localDateTime = LocalDateTime.now();
    //获取系统默认时区
    ZoneId zoneId = ZoneId.systemDefault();
    //时区的日期和时间
    ZonedDateTime zonedDateTime = localDateTime.atZone(zoneId);
    //获取时刻
    Date date = Date.from(zonedDateTime.toInstant());
    System.out.println("格式化前：localDateTime:" + localDateTime + "  Date:" + date);
    //格式化LocalDateTime、Date
    DateTimeFormatter localDateTimeFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    System.out.println("格式化后：localDateTime:" + localDateTimeFormat.format(localDateTime) + "  Date:" + dateFormat.format(date));

输出结果如下：

格式化前：localDateTime:2020-10-27T11:35:09.969  Date:Tue Oct 27 11:35:09 CST 2020
    格式化后：localDateTime:2020-10-27 11:35:09  Date:2020-10-27 11:35:09

#### LocalDate 转 LocalDateTime ####

一般调用 atTime() 方法进行赋值

LocalDate localDate = LocalDate.now();
    LocalDateTime localDateTime1 = localDate.atStartOfDay();
    LocalDateTime localDateTime2 = localDate.atTime(8,20,33);
    LocalDateTime localDateTime3 = localDate.atTime(LocalTime.now());

#### LocalDate 转 Date ####

先调用 atStartOfDay() 方法转 LocalDateTime 再转 Date

LocalDate localDate = LocalDate.now();
    ZoneId zoneId = ZoneId.systemDefault();
    Date date = Date.from(localDate.atStartOfDay().atZone(zoneId).toInstant());

#### Date 转 LocalDateTime ####

先转 ZonedDateTime 再转 LocalDateTime

Date date = new Date();
    ZoneId zoneId = ZoneId.systemDefault();
    LocalDateTime localDateTime = date.toInstant().atZone(zoneId).toLocalDateTime();

#### Date 转 LocalDate ####

跟 LocalDate 同理

Date date = new Date();
    ZoneId zoneId = ZoneId.systemDefault();
    LocalDate localDate = date.toInstant().atZone(zoneId).toLocalDate();

[https_www.cnblogs.com_CF1314_p_13884530.html]: https://www.cnblogs.com/CF1314/p/13884530.html
[LocalDateTime_LocalDate_Date]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0
[LocalDateTime _ LocalDate]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_0
[LocalDateTime _ Date]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_1
[LocalDate _ LocalDateTime]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_2
[LocalDate _ Date]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_3
[Date _ LocalDateTime]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_4
[Date _ LocalDate]: https://www.cnblogs.com/CF1314/p/13884530.html#_label0_5
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