JSON date to Java date? [duplicate]

Answer 1

Note that SimpleDateFormat format pattern Z is for RFC 822 time zone and pattern X is for ISO 8601 (this standard supports single letter time zone names like Z for Zulu).

So new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX") produces a format that can parse both "2013-03-11T01:38:18.309Z" and "2013-03-11T01:38:18.309+0000" and will give you the same result.

Unfortunately, as far as I can tell, you can't get this format to generate the Z for Zulu version, which is annoying.

I actually have more trouble on the JavaScript side to deal with both formats.

Answer 2

If you need to support more than one format you will have to pattern match your input and parse accordingly.

final DateFormat fmt;
if (dateString.endsWith("Z")) {
    fmt = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
} else {
    fmt = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
}

I'd guess you're dealing with a bug in the API you're using which has quoted the Z timezone date pattern somewhere...

Answer 3

That DateTime format is actually ISO 8601 DateTime. JSON does not specify any particular format for dates/times. If you Google a bit, you will find plenty of implementations to parse it in Java.

Here's one

If you are open to using something other than Java's built-in Date/Time/Calendar classes, I would also suggest Joda Time. They offer (among many things) a ISODateTimeFormat to parse these kinds of strings.