How to parse DayOfWeek range - kotlin

Question

As part of an opening times page, I want to parse a DayOfWeek range as (Monday to Friday) rather than creating a String for every day of the working week. Is there a way that this can be done so that the default locale automatically changes the range? I also expect TalkBack to say the text in Desired output when it is selected.
Desired output
English: Monday to Friday
English (US): Monday through Friday
French: du lundi au vendredi
Japanese: 月曜日から金曜日まで
Current code
String dayMonday = DayOfWeek.MONDAY.getDisplayName(TextStyle.FULL, Locale.getDefault())
String dayFriday = DayOfWeek.FRIDAY.getDisplayName(TextStyle.FULL, Locale.getDefault())
myTv.text = dayMonday + dayFriday
Current result
MondayFriday

Answer 1

Horribly belated answer, but to detail the point I was trying to get across in my comment.
Having language files for this which specify the structure of the phrase, as well as another one for the days of the week.
For example, you could have your phrasing files like:
phrasing.properties:
phrasing.dayrange=%1$s to %2$s
phrasing_en_US.properties:
phrasing.dayrange=%1$s through %2$s
phrasing_fr_FR.properties:
phrasing.dayrange=du %1$s au %2$s
Note there is no requirement for spaces before/after the %n$s points. String.format (which will eventually be used, see below) has no such restriction.
And then have your day-name files as:
daynames.properties:
dayname.monday=Monday
dayname.tuesday=Tuesday
...
daynames_fr_FR.properties:
dayname.monday=Lundi
dayname.tuesday=Mardi
And then in your code you do something like:
/**
* Expects {#code fromDay} and {#code toDay} to be
* {#code Strings} in the format {#literal "monday"},
* {#literal "tuesday"}, etc. <emph>in English</emph>.
*/
public String formTheString(final String fromDay,
final String toDay) {
final ResourceBundle phrasingBundle = ResourceBundle.get("phrasing");
// Get the phrasing format: '%1$s ...' style
final String phrasing = phrasingBundle.getString("dayrange");
final ResourceBundle dayNameBundle = ResourceBundle.get("daynames");
// Get the translated day names
final String localisedFromDay = dayNameBundle.getString(fromDay);
final String localisedToDay = dayNameBundle.getString(toDay);
// Use the 'phrasing' as a format, passing in
// the translated day names as the parameters
// to it.
return String.format(phrasing, localisedFromDay, localisedToDay);
}
Alternatively to the 'dayname' files, you can do what the other answer here suggested.

Answer 2

This may help you. This gets a calander, sets it to the first day of the week.
Then, creates a formatter that outputs the day name, for a particular Locale - in this case France, but you can change it to what you like.
Finally, it prints out the day name, adds 5 days, then prints out the dayname again.
public static void main(String arg[]) {
GregorianCalendar cal = new GregorianCalendar();
cal.set(cal.DAY_OF_WEEK,cal.getFirstDayOfWeek());
SimpleDateFormat sdf = new SimpleDateFormat("EEEEEEEEEE", Locale.FRANCE);
System.out.println(sdf.format(cal.getTime()));
cal.add(cal.DAY_OF_WEEK, 5);
System.out.println(sdf.format(cal.getTime()));
}
For this example, I get the output:
lundi
samedi