Question

Possible Duplicate:
How can I increment a date by one day in Java?

public static ArrayList<Calendar> getCalendarsForThreeYears() {
        if (calendars == null) {
            calendars = new ArrayList<Calendar>();
            final Calendar moving = Calendar.getInstance();
            final int targetYear = moving.get(Calendar.YEAR) + 1;
            moving.set(moving.get(Calendar.YEAR) - 1, Calendar.JANUARY, 1);
            final SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yy");
            while (!(moving.get(Calendar.YEAR) == targetYear
                    && moving.get(Calendar.MONTH) == Calendar.DECEMBER && moving
                    .get(Calendar.DAY_OF_MONTH) == 31)) {
                final Calendar c = (Calendar) moving.clone();
                calendars.add(c);
                moving.roll(Calendar.DAY_OF_MONTH, 1);
                System.out.println(sdf.format(c.getTime()));
            }
        }
        return calendars;
    }

I want this to create Calendar objects for 3 years (the one before the current, the current and the next).

However this is an infinite loop since rolling Calendar.DAY_OF_MONTH when it’s on the end of the month won’t roll the Calendar.MONTH

Which is the recommended approach?

Answer 1

moving.add(Calendar.DATE, 1);

will do what you want.

See Calendar#add(int, int):

Adds or subtracts the specified amount of time to the given calendar field, based on the calendar’s rules.

And Calendar.DATE:

Field number for get and set indicating the day of the month.