Java Data Type How to - Get all Monday dates in given month

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Question

We would like to know how to get all Monday dates in given month.

Answer

import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.YearMonth;
import java.util.ArrayList;
import java.util.List;
/*from w ww .  j a v  a  2  s .  com*/
public class Main {

  public static void main(String[] args) {

    System.out.println(weeksInCalendar(YearMonth.now()));
  }

  public static List<LocalDate> weeksInCalendar(YearMonth month) {
    List<LocalDate> firstDaysOfWeeks = new ArrayList<>();
    for (LocalDate day = firstDayOfCalendar(month); stillInCalendar(month, day); day = day
        .plusWeeks(1)) {
      firstDaysOfWeeks.add(day);
    }
    return firstDaysOfWeeks;
  }

  private static LocalDate firstDayOfCalendar(YearMonth month) {
    DayOfWeek FIRST_DAY_OF_WEEK = DayOfWeek.MONDAY;
    return month.atDay(1).with(FIRST_DAY_OF_WEEK);
  }

  private static boolean stillInCalendar(YearMonth yearMonth, LocalDate day) {
    return !day.isAfter(yearMonth.atEndOfMonth());
  }
}

The code above generates the following result.

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