How to get list of dates inside the WEEK_OF_YEAR in android?

Question

For example: given month = 2, and given Year = 2014, i got the list of weeks using this following code. why i applied 1 for month is defaultly the month was start with index only.

SampleCode:

Calendar calendar = Calendar.getInstance();
calendar.set(1, 2014);
calendar.set(2014, 1, 1);
int ndays = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
Set<Integer> weeks = new HashSet<Integer>();
for (int i = 1; i <= ndays; i++) {
weeks.add(calendar.get(Calendar.WEEK_OF_YEAR));
calendar.add(Calendar.DATE, 1);
}

Result: weeks => [8, 9, 5, 6, 7]

After getting this result how can i get what are the dates are available with in the weekofyear. 2014 Febraury month, 5 th week having only one day (saturday). remaining weeks having sevendays except last 9th week.

I Expected Format:

week5 => 1-saturday 
week6 => 2-sunday
         3-monday
         4-tuesday
         5-wednesday
         6-thursday
         7-friday
         8-saturday
week7 => 9-sunday
.
.
.
.
week9 => 23-sunday
         24-monday
         25-tuesday
         26-wednesday
         27-thursday
         28-friday
         29-saturday

some one guide me to get this List< Key,datelist > pair like above result.

Answer 1

why do you want to collect at first the weeks, and then find the days of the week. As you are already looping over all days of a month, you could just create a map, which has the week as key and the list of days as value.

Somehow like that:

    Calendar calendar = Calendar.getInstance();
    calendar.set(1, 2014);
    calendar.set(2014, 1, 1);
    int ndays = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
    Map<Integer, List<Integer>> map = new TreeMap<Integer, List<Integer>>();
    for (int i = 1; i <= ndays; i++) {
        int week = calendar.get(Calendar.WEEK_OF_YEAR);
        int day = calendar.get(Calendar.DAY_OF_MONTH);
        List<Integer> dayList = map.get(week);
        if (dayList == null) {
            dayList = new ArrayList<Integer>();
            map.put(week, dayList);
        }
        dayList.add(day);
        calendar.add(Calendar.DATE, 1);
    }
    //Check the result:
    for (Map.Entry<Integer, List<Integer>> entry : map.entrySet()) {
        System.out.println("Week: " + entry.getKey());
        for (int day : entry.getValue()) {
            System.out.println("Day: " + day);
        }
    }