private static ZoneRulesProvider getProvider ( String zoneId ) { ZoneRulesProvider provider = ZONES . get ( zoneId ) ; if ( provider == null ) { if ( ZONES . isEmpty ( ) ) { throw new ZoneRulesException ( "No time-zone data files registered" ) ; } throw new ZoneRulesException ( "Unknown time-zone ID: " + zoneId ) ; } return provider ; }
Gets the provider for the zone ID .