The getAvailableZoneIds() method of the ZoneOffset class of java.time package is 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 examples illustrate the ZoneOffset.getAvailableZoneIds() method:
Example 1:
// Java code to illustrate getAvailableZoneIds() method  import java.time.*;import java.util.*;  public class GFG {    public static void main(String[] args)    {          // Get the ZoneOffset instance        ZoneOffset zoneOffset            = ZoneOffset.of("+05:30");          // get available zones        // using getAvailableZoneIds()        Set<String> zoneIds            = zoneOffset.getAvailableZoneIds();          // print first record        System.out.println("First ZoneId in list:"                           + zoneIds.iterator().next());    }} |
Output:
First ZoneId in list:Asia/Aden
Example 2:
// Java code to illustrate getAvailableZoneIds() method  import java.time.*;import java.util.*;  public class GFG {    public static void main(String[] args)    {          // Get the ZoneOffset instance        ZoneOffset zoneOffset            = ZoneOffset.of("Z");          // get available zones        // using getAvailableZoneIds()        Set<String> zoneIds            = zoneOffset.getAvailableZoneIds();          // print first record        System.out.println("First ZoneId in list:"                           + zoneIds.iterator().next());    }} |
Output:
First ZoneId in list:Asia/Aden
Reference: Oracle Doc
