Julian to Gregorian date conversion in Scala - scala

Question

I need to convert Julian date (YYYYDDD) to Gregorian date (YYYYMMDD) in Scala.
I got this far:
import java.text.SimpleDateFormat;
val format1 = new java.text.SimpleDateFormat("yyyyddd")
println(format1.parse("2018022"))
The result is: Mon Jan 22 00:00:00 CST 2018
I need help to get output in "YYYYMMDD" format

Answer 1

See if this does it for you.
import java.text.SimpleDateFormat
val format1 = new SimpleDateFormat("yyyyddd")
new SimpleDateFormat("yyyyMMdd").format(format1.parse("2018022"))
//res0: String = 20180122
Or this, which demonstrates the relationships a little better.
val jDate: String = "2018022"
val gDate: String = new SimpleDateFormat("yyyyMMdd").format(
new SimpleDateFormat("yyyyddd").parse(jDate))

Answer 2

You can use below functions to convert the same. I'am using the same function on my website.
function julian2d($indate) {
$year = substr($indate,0,2);
$day = ltrim(substr($indate,strlen($indate)-3,3),'0'); /* Day part with leading zeroes stripped */
if ($year == 70 && $day == 1) $outdate = 1;
else if ($year == 70) $outdate = ($day-1)*24*60*60;
else if ($year >= 0 && $year <= 99 && $day > 0 && $day <= 366) {
$outdate = strtotime('01-Jan-' . $year); /* Date on Jan 1 of the year */
if ($outdate >= 0) {
$outdate = $outdate + ($day-1)*24*60*60;
} else $outdate = FALSE;
} else $outdate = FALSE;
return $outdate;
}