I'm trying to replace parts of a string that contains what should be dates, but which are possibly in an impermissible format. Specifically, all of the dates are in the form "mm/dd/YYYY" and they need to be in the form "YYYY-mm-dd". One caveat is that the original dates may not exactly be in the mm/dd/YYYY format; some are like "5/6/2015". For example, if
val x = "where date >= '05/06/2017'"
then
x.replaceAll("'([0-9]{1,2})/([0-9]{1,2})/([0-9]{4})'", "'$3-$1-$2'")
performs the desired replacement (returns "2017-05-06"), but for
val y = "where date >= '5/6/2017'"
this does not return the desired replacement (returns "2017-5-6" -- for me, an invalid representation). With the Joda Time wrapper nscala-time, I've tried capturing the dates and then reformatting them:
import com.github.nscala_time.time.Imports._
import org.joda.time.DateTime
val f = DateTimeFormat.forPattern("yyyy-MM-dd")
y.replaceAll("'([0-9]{1,2}/[0-9]{1,2}/[0-9]{4})'",
"'"+f.print(DateTimeFormat.forPattern("MM/dd/yyyy").parseDateTime("$1"))+"'")
But this fails with a java.lang.IllegalArgumentException: Invalid format: "$1". I've also tried using the f interpolator and padding with 0s, but it doesn't seem to like that either.
Are you not able to do additional processing on the captured groups ($1, etc.) inside the replaceAll? If not, how else can I achieve the desired result?