Tom :
I have an ISO based week number that is calculated using the following Java 8 LocalDate API
int weekNumOfYear = LocalDate#get(IsoFields.WEEK_OF_WEEK_BASED_YEAR)
Given the year, and the week number (eg, 201927),How could I calculate the start day and end day for this week(201917)?
I am Using Calendar class for this problem, but not sure it is correct(especially, whether is has followed the ISO format)
Update： The following code doesn't work correctly for 201953, there is no 53th week for 2019
@Test
public void testGetWeekDays() {
Integer year = 2019;
Integer week = 27;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
//Use ISO format
cal.setMinimalDaysInFirstWeek(4);
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.set(Calendar.YEAR, year);
cal.set(Calendar.WEEK_OF_YEAR, week);
cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
String beginDate = sdf.format(cal.getTime());
cal.add(Calendar.DAY_OF_WEEK, 6);
String endDate = sdf.format(cal.getTime());
System.out.println(beginDate);
System.out.println(endDate);
}
Deadpool :
You can also use with to get start day and end day of week
System.out.println(localDate.with(DayOfWeek.MONDAY));
System.out.println(localDate.with(DayOfWeek.SUNDAY));
If you want to get start day and end day from week number, then use ISO_WEEK_DATE
LocalDate startDay = LocalDate.parse("2019-W26-1", DateTimeFormatter.ISO_WEEK_DATE);
LocalDate endDay = LocalDate.parse("2019-W26-7", DateTimeFormatter.ISO_WEEK_DATE);
One digit for the day-of-week. The value run from Monday (1) to Sunday (7).
Guess you like
Origin http://43.154.161.224:23101/article/api/json?id=328382&siteId=1