calculate weeks for one month in jodatime

Question

Is it possible to calculate the weeks of one month in jodatime?

I need something like this:

Month: July

• Week of Year 27; 1-7. July
• Week of Year 28; 9-14. July
• Week of Year 29; 16-21. July
• Week of Year 30; 23-31. July

Month: August

• Week of Year 31; 1-4. Aug
• Week of Year 32; 6-11. Aug
• Week of Year 33; 13-18. Aug
• Week of Year 34; 20-25. Aug
• Week of Year 35; 27-31. Aug

I know that i can get the week of Year in joda time like this:

new LocalDate().weekOfWeekYear()

But i don´t know how to get the related dates.

Answer 1

To retrieve the range of a week, just create an object pointing to the first and last day of the week, then just pull the day of month from it.

int weekOfYear = 32;

LocalDate firstDay = new LocalDate().withWeekOfWeekyear(weekOfYear).withDayOfWeek(1);
LocalDate lastDay = new LocalDate().withWeekOfWeekyear(weekOfYear).withDayOfWeek(7);

System.out.println("Week of Year "+weekOfYear+"; "+firstDay.toString("d MMM")+" - "+lastDay.toString("d MMM"));

You can also extract the day like this:

int weekStart = firstDay.getDayOfMonth();
int weekEnd = lastDay.getDayOfMonth();

You can then use the same technique to retrieve the weeks in a month as well.

int firstWeekInMonth = new LocalDate().withMonthOfYear(month).withDayOfMonth(1).getWeekOfYear();
int lastWeekInMonth = new LocalDate().withMonthOfYear(month).dayOfMonth().withMaximalValue().getWeekOfYear();

Probably you might want to limit the start and end-dates to stay within the range of the month, otherwise you could get things like '30 - 5 Sep'.

Answer 2

fixing some variables:

int weekOfYear = 32;

LocalDate firstDay = new LocalDate().withWeekOfWeekyear(weekOfYear).withDayOfWeek(1);
LocalDate lastDay = new LocalDate().withWeekOfWeekyear(weekOfYear).withDayOfWeek(6);

int weekStart = firstDay.getDayOfMonth();    
int weekEnd = lastDay.getDayOfMonth();

System.out.println("Week of Year "+weekOfYear+"; "+weekStart+"-"+weekEnd+" "+month);

Answer 3

My solution, considering the other answers

 public List<Pair<LocalDate, LocalDate>> getWeeksInMonth(LocalDate data) {

        int firstWeekInMonth = data.withDayOfMonth(1).getWeekOfWeekyear();
        int lastWeekInMonth = data.dayOfMonth().withMaximumValue().getWeekOfWeekyear();

        List<Pair<LocalDate, LocalDate>> weeks = new cicero.minhasfinancas.util.array.ArrayList<>();
        while (firstWeekInMonth <= lastWeekInMonth) {

            LocalDate firstDay = new LocalDate().withWeekOfWeekyear(firstWeekInMonth).withDayOfWeek(1);
            LocalDate lastDay = new LocalDate().withWeekOfWeekyear(firstWeekInMonth).withDayOfWeek(7);
            weeks.add(new Pair<>(firstDay, lastDay));
            firstWeekInMonth++;
        }

        return weeks;
    }

    public class Pair<V1, V2>{

        V1 first;
        V2 second;

        public Pair(V1 first, V2 second) {
            this.first = first;
            this.second = second;
        }

        public V1 getFirst() {
            return first;
        }

        public void setFirst(V1 first) {
            this.first = first;
        }

        public V2 getSecond() {
            return second;
        }

        public void setSecond(V2 second) {
            this.second = second;
        }
    }