How to include just enough locale data with an app to be able to format dates in three locales?

Question

I would like to be able to format java.util.Date objects in a "long" English, Spanish, and German date format. By "long" I mean the locale-dependent date format that corresponds to the LONG style pattern constant in java.text.DateFormat:

DateFormat.getDateInstance(DateFormat.LONG, myLocale).format(myDate);

With a standard JRE, I get date strings like:

November 22, 2010
22 de noviembre de 2010
22. November 2010

as expected. On Android 1.5, however, I get:

November 22, 2010
2010 11 22
2010 11 22

Is there a way that I can include just enough locale information with my app to be able to format dates correctly in long English, Spanish, and German formats using java.text.DateFormat?

Answer 1

First of all, the dates formatting in JRE is known for incorrect behavior for many locales (invalid Polish, Czech and Russian long dates, invalid Polish short date; And this are just examples of what I know for sure). So I wouldn't trust this source of information much.

If you want to implement your own long date formatting logic, here is what I would do:

String spanishDatePattern = "{0,number,00} {1} {2,number,####}";
String spanishLongDateMonthNameNovember = "de noviembre de";

Object[] arguments = { new Integer(date.getDate()),
                       spanishLongDateMonthNameNovember,
                       new Integer(date.getYear()) };
String formattedDate = MessageFormat.format(spanishDatePattern,
                arguments);

In this case you will need 13 messages per language (12 month ~names and 1 pattern). Not that much, I believe.

Of course this was just an example, in reality you would probably need to also add logic to resolve month names (having keys with name ending with month number, i.e. longDateFormatMonthName.0=January?).