How to convert Youtube API V3 duration in Java

I may be late for the party, it's actually very simple. Although there may be better ways of doing this. duration is in milliseconds.

public long getDuration() {
    String time = "PT15H12M46S".substring(2);
    long duration = 0L;
    Object[][] indexs = new Object[][]{{"H", 3600}, {"M", 60}, {"S", 1}};
    for(int i = 0; i < indexs.length; i++) {
        int index = time.indexOf((String) indexs[i][0]);
        if(index != -1) {
            String value = time.substring(0, index);
            duration += Integer.parseInt(value) * (int) indexs[i][1] * 1000;
            time = time.substring(value.length() + 1);
        }
    }
    return duration;
}

Joda Time is the go-to library for time-related functions of any kind.

For this specific case ISOPeriodFormat.standard() returns a PeriodFormatter that can parse and format that format.

The resulting object is a Period (JavaDoc). Getting the actual number of seconds would then be period.toStandardSeconds().getSeconds(), but I suggest you just handle the duration as a Period object (for ease of handling and for type safety).

Edit: a note from future me: this answer is several years old now. Java 8 brought java.time.Duration along which can also parse this format and doesn't require an external library.

Solution in Java 8:

Duration.parse(duration).getSeconds()