Convert Date to String in groovy

import java.text.SimpleDateFormat

long lTime = new Date().time

String formattedDate = getUTCDateString(lTime)
println formattedDate

def getUTCDateString(long lTime)
{
Date lDate = new Date(lTime)
def cal = new GregorianCalendar(TimeZone.getTimeZone('UTC'))
cal.set(lDate[Calendar.YEAR],lDate[Calendar.MONTH],lDate[Calendar.DATE],lDate[Calendar.HOUR_OF_DAY],lDate[Calendar.MINUTE],lDate[Calendar.SECOND])
String formattedDate = new SimpleDateFormat("yyyy-mm-dd hh:mm").format(cal.time);
return formattedDate
}

Check if String is Number

String nbrStr = "30239023902390239023902323"
boolean b = nbrStr.isNumber()
assert b == true

Groovy String to Integer

Converting a String to Number

String nbrStr = "100"
int i = nbrStr.toInteger()
assert i==100