date problem

[pouncer]

        Calendar cal1 = Calendar.getInstance();
        cal1.set(2010, 01, 29);
        Date date = cal1.getTime();
        SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
        String strDate = formatter.format(date);
        
        System.out.println("str date.......... " + strDate);

It prints out

str date.......... 01/03/2010

why isnt it printing 29/01/2010

[dlorde]

It pays to read the API docs - Java Calendar months start at 0 for January, so you are formatting the 29th of February for 2010 which isn't a leap year, so it rolls over to the start of the next month.

If you use the Calendar constants, it will work as expected:

cal1.set(2010, Calendar.JANUARY, 29);

Unless in communicating with it [a computer] one says exactly what one means, trouble is bound to result...
A. Turing

[ProgramThis]

Which I always used to get confused myself since everything else in the calendar class is NOT zero based. A little consistency guys?

The first month of the year is JANUARY which is 0; the last depends on the number of months in a year.

The first week of the year, as defined by getFirstDayOfWeek() and getMinimalDaysInFirstWeek(), has value 1

The first day of the month has value 1.

[keang]

Which I always used to get confused myself since everything else in the calendar class is NOT zero based. A little consistency guys?

The whole of the date/calendar system is a mess, hence people who need to do serious work with dates tend to use a third party implementation such as Joda Time instead.

I believe a system similar to Joda time (JSR 310) is planned for inclusion in Java release 7 and not before time if you ask me.