Question

Anyone know of a Java library that can parse time strings such as “30min” or “2h 15min” or “2d 15h 30min” as milliseconds (or some kind of Duration object). Can Joda-Time do something like this?

(I have an ugly long method to maintain that does such parsing and would like to get rid of it / replace it with something that does a better job.)

Answer 1

You’ll probably have to tweak this a bit for your own format, but try something along these lines:

PeriodFormatter formatter = new PeriodFormatterBuilder()
    .appendDays().appendSuffix("d ")
    .appendHours().appendSuffix("h ")
    .appendMinutes().appendSuffix("min")
    .toFormatter();

Period p = formatter.parsePeriod("2d 5h 30min");

note that there is a appendSuffix that takes a variants parameter if you need to make it more flexible.

Update: Joda Time has since added Period.toStandardDuration(), and from there you can use getStandardSeconds() to get the elapsed time in seconds as a long.

If you’re using an older version without these methods you can still calculate a timestamp yourself by assuming the standard 24/hr in a day, 60min/hr, etc. (In this case, take advantage of the constants in the DateTimeConstants class to avoid the need for magic numbers.)