[java] Java/Groovy - simple date reformatting

I'm new to Java/Groovy development and I have a simple string that I would like to reformat, however I get an 'Unparseable date' error when I attempt to run the following:

import java.text.SimpleDateFormat 
import java.util.Date

String oldDate
Date date
String newDate 

oldDate = '04-DEC-2012'
date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S").parse(oldDate)
newDate = new SimpleDateFormat("M-d-yyyy").format(date) 

println newDate

I'm sure it's something simple, but the solution eludes me. Can anyone help?

Your DateFormat pattern does not match you input date String. You could use

new SimpleDateFormat("dd-MMM-yyyy")

oldDate is not in the format of the SimpleDateFormat you are using to parse it.

Try this format: dd-MMM-yyyy - It matches what you're trying to parse.