Show time in format yyyy-MM-ddThh:mm:ss.SSS

My requirement is to convert a time (long) to a String with this date format:


yyyy-MM-ddThh:mm:ss.SSS

For instance: 2017-03-07T03:52:31.298

My implementation:

private final static String DATE_FORMAT = "yyyy-MM-dd_hh:mm:ss.SSS";

private final static DateFormat DF =
        new SimpleDateFormat(DATE_FORMAT, Locale.ENGLISH);

public static String formatTime(long time) {
    return DF.format(time).replace('_', 'T');
}

The underscore trick is to avoid the Illegal pattern character T error I was getting if I had a T character in DATE_FORMAT. I am sure there is a better way to do this?

Also, I am sure more explicit names can be found for DATE_FORMAT/DF?

Don't reinvent the wheel, this is java.time.format.DateTimeFormatter.ISO_LOCAL_DATE_TIME.

long time = System.currentTimeMillis();
ISO_LOCAL_DATE_TIME.format(Instant.ofEpochMilli(time).atZone(ZoneOffset.UTC))
// "2017-03-07T12:09:04.374"

StackExchange Code Review Q#157122, answer score: 16