Parse string description of timezone

Question

I get information about timezone in such string format.

 (UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius

Is it somehow possible to parse it into some TimeZone object in Java with standard library or external one?

Answer 1

Depending how you want to use the TimeZone afterwards you might either create a custom one

String input = "(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius";
// assuming the format is always fixed at the beginning
String timeZoneOffset = input.substring(4,10);
TimeZone timeZone = TimeZone.getTimeZone("GMT" + timeZoneOffset);
System.out.println("timeZone = " + timeZone);

output (line wrapped)

timeZone = sun.util.calendar.ZoneInfo[id="GMT+02:00",offset=7200000,dstSavings=0,\
useDaylight=false,transitions=0,lastRule=null]

You might get into trouble related to the daytime savings.

Or you create a lookup map with an entry for each offset (stripped down code snipped)

String input = "(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius";
// assuming the format is always fixed at the beginning
String timeZoneOffset = input.substring(4,10);

// needs to be initialized somewhere
Map<String, TimeZone> timeZones = new HashMap<>();
// you need to add all offsets
timeZones.put("+02:00", TimeZone.getTimeZone("EET"));

System.out.println("timeZone lookup = " + timeZones.get(timeZoneOffset));

output (line wrapped)

timeZone lookup = sun.util.calendar.ZoneInfo[id="EET",offset=7200000,dstSavings=3600000,\
useDaylight=true,transitions=123,lastRule=java.util.SimpleTimeZone[id=EET,offset=7200000,\
dstSavings=3600000,useDaylight=true,startYear=0,startMode=2,startMonth=2,\
startDay=-,startDayOfWeek=1,startTime=3600000,startTimeMode=2,endMode=2,\
endMonth=9,endDay=-1,endDayOfWeek=1,endTime=3600000,endTimeMode=2]]