The getAvailableZoneIds() method of the ZoneId class used to get the set of available zone IDs.This set includes all available region-based IDs.The ID can be passed to of(String) to create a ZoneId.The set of zone IDs can increase over time, although in a typical application the set of IDs is fixed.
Syntax:
public static Set getAvailableZoneIds()
Parameters: This method does not accepts any parameter.
Return value: This method returns Set which are a modifiable copy of the set of zone IDs.
Below programs illustrate the getAvailableZoneIds() method:
Program 1:
// Java program to demonstrate// ZoneId.getAvailableZoneIds() method  import java.time.*;import java.util.Set;  public class GFG {    public static void main(String[] args)    {          // get available zones using zoneIds()        Set<String> zoneIds = ZoneId.getAvailableZoneIds();          // print first record        System.out.println("First ZoneId in list:" + zoneIds.iterator().next());    }} |
Output:
First ZoneId in list:Asia/Aden
Program 2:
// Java program to demonstrate// ZoneId.getAvailableZoneIds() method  import java.time.*;import java.util.*;  public class GFG {    public static void main(String[] args)    {          // get available zones using zoneIds()        Set<String> allZones = ZoneId.getAvailableZoneIds();          // create ArrayList from Set        List<String> zoneList = new ArrayList<String>(allZones);        Collections.sort(zoneList);          // printing first 5 zoneid with offset        LocalDateTime dt = LocalDateTime.now();        for (int i = 0; i < 5; i++) {              // get zoneid then ZonedDateTime and offset            // from that ZoneId            String s = zoneList.get(i);            ZoneId zoneid = ZoneId.of(s);            ZonedDateTime zoneddate = dt.atZone(zoneid);            ZoneOffset offset = zoneddate.getOffset();            System.out.println("ZoneId = " + zoneid + " offset = " + offset);        }    }} |
Output:
ZoneId = Africa/Abidjan offset = Z ZoneId = Africa/Accra offset = Z ZoneId = Africa/Addis_Ababa offset = +03:00 ZoneId = Africa/Algiers offset = +01:00 ZoneId = Africa/Asmara offset = +03:00
