In order to convert from Date to Instant, the solution can rely on the Date.toInstant() method. The reverse can be accomplished via the Date.from(Instant instant) method:

• Date to Instant can be accomplished like this:

Date date = new Date();

// e.g., 2019-02-27T12:02:49.369Z, UTC
Instant instantFromDate = date.toInstant();

• Instant to Date can be accomplished like this:

Instant instant = Instant.now();

// Wed Feb 27 14:02:49 EET 2019, default system time zone
Date dateFromInstant = Date.from(instant);

Let's quickly wrap these snippets of code in two utility methods, defined in a utility class—DateConverters:

public static Instant dateToInstant(Date date) {

  return date.toInstant();
}

public static Date instantToDate(Instant instant) {

  return Date.from(instant);
}

Further, let's enrich this class with the methods from the following screenshot:

The constant from the screenshot, DEFAULT_TIME_ZONE, is the system default time zone:

public static final ZoneId DEFAULT_TIME_ZONE = ZoneId.systemDefault();