/** Converts UTC as milliseconds to time field values. */
protected void computeFields() {
int rawOffset = getTimeZone().getRawOffset();
long localMillis = time + rawOffset;
// Check for very extreme values -- millis near Long.MIN_VALUE or
// Long.MAX_VALUE. For these values, adding the zone offset can push
// the millis past MAX_VALUE to MIN_VALUE, or vice versa. This produces
// the undesirable effect that the time can wrap around at the ends,
// yielding, for example, a Date(Long.MAX_VALUE) with a big BC year
// (should be AD). Handle this by pinning such values to Long.MIN_VALUE
// or Long.MAX_VALUE. - liu 8/11/98 CR 4149677
if (time > 0 && localMillis < 0 && rawOffset > 0) {
localMillis = Long.MAX_VALUE;
} else if (time < 0 && localMillis > 0 && rawOffset < 0) {
localMillis = Long.MIN_VALUE;
}
// Time to fields takes the wall millis (Standard or DST).
timeToFields(localMillis);
long days = (long) (localMillis / ONE_DAY);
int millisInDay = (int) (localMillis - (days * ONE_DAY));
if (millisInDay < 0) millisInDay += ONE_DAY;
// Call getOffset() to get the TimeZone offset.
// The millisInDay value must be standard local millis.
int dstOffset =
getTimeZone()
.getOffset(
AD,
this.fields[YEAR],
this.fields[MONTH],
this.fields[DATE],
this.fields[DAY_OF_WEEK],
millisInDay)
- rawOffset;
// Adjust our millisInDay for DST, if necessary.
millisInDay += dstOffset;
// If DST has pushed us into the next day,
// we must call timeToFields() again.
// This happens in DST between 12:00 am and 1:00 am every day.
// The call to timeToFields() will give the wrong day,
// since the Standard time is in the previous day
if (millisInDay >= ONE_DAY) {
long dstMillis = localMillis + dstOffset;
millisInDay -= ONE_DAY;
// As above, check for and pin extreme values
if (localMillis > 0 && dstMillis < 0 && dstOffset > 0) {
dstMillis = Long.MAX_VALUE;
} else if (localMillis < 0 && dstMillis > 0 && dstOffset < 0) {
dstMillis = Long.MIN_VALUE;
}
timeToFields(dstMillis);
}
// Fill in all time-related fields based on millisInDay.
// so as not to perturb flags.
this.fields[MILLISECOND] = millisInDay % 1000;
millisInDay /= 1000;
this.fields[SECOND] = millisInDay % 60;
millisInDay /= 60;
this.fields[MINUTE] = millisInDay % 60;
millisInDay /= 60;
this.fields[HOUR_OF_DAY] = millisInDay;
this.fields[AM_PM] = millisInDay / 12;
this.fields[HOUR] = millisInDay % 12;
}
