CODEWITHSUNDEEP
javaandroiddatecollections
Ndroid
Ndroid

Reputation: 11

How to sort array of dates by today/this week/this month - android

I have Array of String dates. i need to fill in 3 ListViews, Today list ,dates from this week and dates from this month. Format is : dd //mm // yy. example:

{"03.02.16","02.03.16","03.03.16","29.02.16"}

"03.03.16"-is today. "29.02.16"- is from last month but it was this week so i need to add it to this week list. "02.03.16"- need to be in this week and this month list.

there is a way to sort date like that in java/android?

Upvotes: 1

Views: 1623

Answers (1)

Tudor Luca
Tudor Luca

Reputation: 6419

This is an implementation using JSR-310. On Android, you can use Jake Wharton's port ThreeTenABP.

DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("dd.MM.yy");

final List<String> yourDates = someDates();

final List<LocalDate> dates = parseDates(yourDates);

final LocalDate today = getToday(dates);
final List<LocalDate> thisWeek = getDatesThisWeek(dates);
final List<LocalDate> thisMonth = getDatesThisMonth(dates);

...

@Nullable
private LocalDate getToday(List<LocalDate> dates) {
    final LocalDate today = LocalDate.now();
    for (LocalDate date : dates) {
        if (today.equals(date)) {
            return date;
        }
    }

    return null;
}

private List<LocalDate> getDatesThisWeek(List<LocalDate> dates) {
    final TemporalField dayOfWeek = WeekFields.of(Locale.getDefault()).dayOfWeek();
    final LocalDate start = LocalDate.now().with(dayOfWeek, 1);
    final LocalDate end = start.plusDays(6);

    return getDatesBetween(dates, start, end);
}

private List<LocalDate> getDatesThisMonth(List<LocalDate> dates) {
    final LocalDate now = LocalDate.now();
    final LocalDate start = now.withDayOfMonth(1);
    final LocalDate end = now.withDayOfMonth(now.lengthOfMonth());

    return getDatesBetween(dates, start, end);
}

private List<LocalDate> getDatesBetween(List<LocalDate> dates, LocalDate start, LocalDate end) {
    final List<LocalDate> datesInInterval = new ArrayList<>();

    for (LocalDate date : dates) {
        if (start.equals(date) || end.equals(date) || (date.isAfter(start) && date.isBefore(end))) {
            datesInInterval.add(date);
        }
    }

    return datesInInterval;
}

private List<LocalDate> parseDates(List<String> stringDates) {
    final List<LocalDate> dates = new ArrayList<>(stringDates.size());
    for (String stringDate : stringDates) {
        dates.add(LocalDate.parse(stringDate, FORMATTER));
    }

    return dates;
}

Update: you can also find the implementation here.

Upvotes: 2

Related Questions