java: Convert a string which represents a two digit year to four digits

Question

This question has been asked many times but I have an issue which I feel makes it a unique question.

Here it goes.

I have a string which represents a two digit year i.e. to write 2016 I input 16

I have a requirement to convert a two digit year to four digit year i.e. 16 becomes 2016.

After going through some questions and answers I made the following findings

Solution 1

DateFormat sdfp = new SimpleDateFormat("dd.mm.yy");
Date d = sdfp.parse(input);
DateFormat sdff = new SimpleDateFormat("yyyy-MM-dd");
String date = sdff.format(d);

This would be great but I do not have a month or day in my case just a year and I could not find a way to create a date object with just the year.

Solution 2

The above could be solved with a Calendar object but it does not allow the input an of a two digit year for its year field.

Edit Forgot to mention I cannot use Joda-Time because I'm working on the Android platform and it would increase the size of my project for just this small use

Answer 1

Why not just remove the part of month and day from the format?

DateFormat sdfp = new SimpleDateFormat("yy");
Date d = sdfp.parse(input);
DateFormat sdff = new SimpleDateFormat("yyyy");
String date = sdff.format(d);

LIVE

Here is the rule about how SimpleDateFormat interpret the abbreviated year. (bold by me)

For parsing with the abbreviated year pattern ("y" or "yy"), SimpleDateFormat must interpret the abbreviated year relative to some century. It does this by adjusting dates to be within 80 years before and 20 years after the time the SimpleDateFormat instance is created. For example, using a pattern of "MM/dd/yy" and a SimpleDateFormat instance created on Jan 1, 1997, the string "01/11/12" would be interpreted as Jan 11, 2012 while the string "05/04/64" would be interpreted as May 4, 1964.