I want to get the day (e.g. 1st Sunday, 2nd Tuesday) of this month as Calendar. How can I achieve this with class Calendar in Android? Thanks.
Edit: The elegant solution uses a DateTimeFormatter
:
Locale language = Locale.ENGLISH;
Map<Long, String> ordinalNumber = new HashMap<>(8);
ordinalNumber.put(1L, "1st");
ordinalNumber.put(2L, "2nd");
ordinalNumber.put(3L, "3rd");
ordinalNumber.put(4L, "4th");
ordinalNumber.put(5L, "5th");
DateTimeFormatter dayFormatter = new DateTimeFormatterBuilder()
.appendText(ChronoField.ALIGNED_WEEK_OF_MONTH, ordinalNumber)
.appendPattern(" EEEE 'of the month'")
.toFormatter(language);
LocalDate date = LocalDate.now(ZoneId.of("Pacific/Auckland"));
String dayString = date.format(dayFormatter);
System.out.println("" + date + " is the " + dayString);
When I ran this snippet just now, it output:
2019-06-05 is the 1st Wednesday of the month
Obviously you can put in any date you wish other than today’s date in New Zealand.
The concept of aligned week of month defines the first week of the month as days 1 through 7, the 2nd week is 8 through 14, etc. So when a Wednesday is in week 1 according to this scheme, we also know that it must be the 1st Wednesday of the month. Same argument for other numbers.
I am not using the Calendar
class you mentioned since it is poorly designed and long outdated. Instead I am using java.time, the modern Java date and time API.
Original code (a bit shorter, but nevertheless does a little more hand work):
String[] ordinalNumber = { "0th", "1st", "2nd", "3rd", "4th", "5th" };
LocalDate date = LocalDate.now(ZoneId.of("Pacific/Auckland"));
DayOfWeek day = date.getDayOfWeek();
int numberDowOfMonth = date.get(ChronoField.ALIGNED_WEEK_OF_MONTH);
String dayString = String.format(language, "%s %s of the month",
ordinalNumber[numberDowOfMonth],
day.getDisplayName(TextStyle.FULL_STANDALONE, language));
System.out.println("" + date + " is the " + dayString);
Output is the same as above.
There’s an unused 0th element of my ordinalNumber
array. I only put it there because arrays are 0-based in Java and I wanted the other strings to be aligned with the numbers.
Yes, java.time works nicely on older and newer Android devices. It just requires at least Java 6.
org.threeten.bp
with subpackages.java.time
was first described.java.time
to Java 6 and 7 (ThreeTen for JSR-310).