Convert java.time.LocalDate into java.util.Date ty

Question

I want to convert java.time.LocalDate into java.util.Date type. Because I want to set the date into JDateChooser. Or is there any date chooser that supports java.time dates?

Answer 1

Here's a utility class I use to convert the newer java.time classes to java.util.Date objects and vice versa:

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Date;

public class DateUtils {

  public static Date asDate(LocalDate localDate) {
    return Date.from(localDate.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant());
  }

  public static Date asDate(LocalDateTime localDateTime) {
    return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
  }

  public static LocalDate asLocalDate(Date date) {
    return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDate();
  }

  public static LocalDateTime asLocalDateTime(Date date) {
    return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDateTime();
  }
}

Edited based on @Oliv comment.

Answer 2

You can use java.sql.Date.valueOf() method as:

Date date = java.sql.Date.valueOf(localDate);

No need to add time and time zone info here because they are taken implicitly.
See LocalDate to java.util.Date and vice versa simpliest conversion?

Answer 3

Date date = Date.from(localDate.atStartOfDay(ZoneId.systemDefault()).toInstant());

That assumes your date chooser uses the system default timezone to transform dates into strings.

Answer 4

In order to create a java.util.Date from a java.time.LocalDate, you have to

• add a time to the LocalDate
• interpret the date and time within a time zone
• get the number of seconds / milliseconds since epoch
• create a java.util.Date

The code might look as follows:

LocalDate localDate = LocalDate.now();
Date date = new Date(localDate.atStartOfDay(ZoneId.of("America/New_York")).toEpochSecond() * 1000);

Answer 5

This solution here is a bit longer and you could include something for the time here as well but as far as I understand your problem you just need the actual date.

int day = this.datePicker2.getDate().getDayOfMonth();
int month = this.datePicker2.getDate().getMonthValue();
int year = this.datePicker2.getDate().getYear();
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, month-1);
calendar.set(Calendar.DATE, day);
Date date = calendar.getTime();

Might not look that elegant but it works. Note: month-1 is used because the months in calendar start with 0.

Answer 6

This works for me:

java.util.Date d = new SimpleDateFormat("yyyy-MM-dd").parse(localDate.toString());

https://docs.oracle.com/javase/8/docs/api/java/time/LocalDate.html#toString--