Java Sample Code to convert a calendar to string object

//2020-06-05T00:00:00.000Z

public static String calendarToStr(Calendar calendar) {

try {

DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);

Instant instant = calendar.getTime().toInstant();

LocalDateTime localDateTime = instant.atZone(ZoneId.of(DEFAULT_ZONE_ID, ZoneId.SHORT_IDS)).toLocalDateTime();

String formattedDate = inputFormatter.format(localDateTime);

return formattedDate;

} 

                catch (Exception e) {

e.printStackTrace();

}

return null;

}