From LocalDate to LocalDateTime

How to convert LocalDate to LocalDateTime?

Local Date and Local DateTime is introduced in Java 8 under package java.time.

First we need to understand what we have and what we want to get.

From LocalDate we have: Instant + System default time zone.
What we want to have is: Instant + System default time zone + Local Time

LocalDateTime.of() methods gives us so many options to create LocalDateTime. On of the option is as given below

LocalDate localDate = LocalDate.now()

LocalDateTime ldt= LocalDateTime.of(localDate, LocalTime.MIN);

Here LocalTime.Min will give us the Day's start time i.e. 00:00:00
To get LocalDateTime with current time we can use following:

LocalDateTime localDateTimeNow = LocalDateTime.of(localDate, LocalTime.now());

Example:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

import java.time.Instant; import java.time.LocalDate; import java.time.LocalDateTime; import java.time.LocalTime; import java.time.ZoneId; import java.util.Date; public class LocalDateToLocalDateTime { public static void main(String[] args) { // Asia/Kuala_Lumpur +8 ZoneId defaultZoneId = ZoneId.systemDefault(); System.out.println("System Default TimeZone : " + defaultZoneId); Date date = new Date(); System.out.println("date : " + date); // 1. Convert Date -> Instant Instant instant = date.toInstant(); System.out.println("instant : " + instant); // Zone : UTC+0 // 2. Instant + system default time zone + toLocalDate() = LocalDate LocalDate localDate = instant.atZone(defaultZoneId).toLocalDate(); System.out.println("localDate : " + localDate); // 3. Instant + system default time zone + toLocalDateTime() = // LocalDateTime LocalDateTime localDateTime = instant.atZone(defaultZoneId).toLocalDateTime(); System.out.println("localDateTime : " + localDateTime); LocalDateTime ldt = LocalDateTime.of(localDate, LocalTime.now()); System.out.println("localDateTime : " + ldt); } }