Determine TimeZone from a JSON String?

I'm querying a JSON API that returns something like this:

{
  "created_time": "2017-01-05T16:32:29+0100",
  "updated_time": "2017-01-11T09:38:41+0100",
  "id": "23842536731240607"
}

I need to store the times in UTC format, but in order to change the timezone, I first need to parse it as a ZonedDateTime.

To convert "+0100" to "+01:00" is easy enough. But how can I parse the (created/updated)_time into a ZonedDateTime so I can convert it to UTC?

Solution

Well let me break down the problem statement.

First if you are querying an API then it can be assumed that they are following some standard Date-Time format (even if you are creating one). Looking over the given date it looks like they follow - ** ISO 8601 - Date and time format **

So the problem is how to parse ISO 8601 - Date and time format

What are best options available ?

Using Joda Time.

Using Date Time API Java-8

//Joda
String jtDate = "2010-01-01T12:00:00+01:00";
DateTimeFormatter yoda = ISODateTimeFormat.dateTimeNoMillis();
System.out.println(parser2.parseDateTime(jtDate));

//using Java 8 (As you specified - To convert "+0100" to "+01:00"    is easy enough.)
String strDate = "2017-01-05T16:32:29+01:00";
DateTimeFormatter timeFormatter = DateTimeFormatter.ISO_DATE_TIME;
TemporalAccessor convertMe = timeFormatter.parse(strDate);
Date date = Date.from(Instant.from(convertMe));
System.out.println(date);

Hope it helps :)