Java – what is the best way to parse dates in mm / DD / yy format and adjust them to the current / previous century?

One of our customers wants to be able to enter a date with only 2 digits in the year The date will be in the past, so if the two digit year is after this year, we want it to work in the last century, but if the two digit year is equal to or less than that year, it will work in the current century

As of today 10 / 30 / 2008

01/01/01 = 01/01/2001

01/01/09 = 01/01/1909

This is a strange request. I solved this problem. I just don't like my solution It feels like there's a better way to do this

Thank you for your help

public static String stupidDate(String dateString)
{
    String twoDigitYear = StringUtils.right(dateString,2);
    String newDate = StringUtils.left(dateString,dateString.length() - 2);
    int year = NumberUtils.toInt(twoDigitYear);
    Calendar c = GregorianCalendar.getInstance();
    int centuryInt = c.get(Calendar.YEAR) - year;
    newDate = newDate + StringUtils.left(Integer.toString(centuryInt),2) + twoDigitYear;
    return newDate;
}

Solution

Groovy scripts (easy to throw into Java) demonstrate the @ bobice point about simpledateformat

java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat('MM/dd/yy')
java.text.SimpleDateFormat fmt = new java.text.SimpleDateFormat('yyyy-MM-dd')
Calendar cal = Calendar.getInstance()
cal.add(Calendar.YEAR,-100)
sdf.set2DigitYearStart(cal.getTime())
dates = ['01/01/01','10/30/08','01/01/09']
dates.each {String d ->
  println fmt.format(sdf.parse(d))
}

Yeilds

2001-01-01
2008-10-30
1909-01-01