How do I get localized date pattern string?

Question

It is quite easy to format and parse Java Date (or Calendar) classes using instance of DateFormat, i.e. I could format current date into short localize date like this:

Answer 1

Java 8 provides some useful features out of the box for working with and formatting/parsing date and time, including handling locales. Here is a brief introduction.

Basic Patterns

In the simplest case to format/parse a date you would use the following code with a String pattern:

DateTimeFormatter.ofPattern("MM/dd/yyyy")

The standard is then to use this with the date object directly for formatting:

return LocalDate.now().format(DateTimeFormatter.ofPattern("MM/dd/yyyy"));

And then using the factory pattern to parse a date:

return LocalDate.parse(dateString, DateTimeFormatter.ofPattern("MM/dd/yyyy"));

The pattern itself has a large number of options that will cover the majority of usecases, a full rundown can be found at the javadoc location here.

Locales

Inclusion of a Locale is fairly simple, for the default locale you have the following options that can then be applied to the format/parse options demonstrated above:

DateTimeFormatter.ofLocalizedDate(dateStyle);

The 'dateStyle' above is a FormatStyle option Enum to represent the full, long, medium and short versions of the localized Date when working with the DateTimeFormatter. Using FormatStyle you also have the following options:

DateTimeFormatter.ofLocalizedTime(timeStyle);
DateTimeFormatter.ofLocalizedDateTime(dateTimeStyle);
DateTimeFormatter.ofLocalizedDateTime(dateTimeStyle, timeStyle);

The last option allows you to specify a different FormatStyle for the date and the time. If you are not working with the default Locale the return of each of the Localized methods can be adjusted using the .withLocale option e.g

DateTimeFormatter.ofLocalizedTime(timeStyle).withLocale(Locale.ENGLISH);

Alternatively the ofPattern has an overloaded version to specify the locale too

DateTimeFormatter.ofPattern("MM/dd/yyyy",Locale.ENGLISH);

I Need More!

DateTimeFormatter will meet the majority of use cases, however it is built on the DateTimeFormatterBuilder which provides a massive range of options to the user of the builder. Use DateTimeFormatter to start with and if you need these extensive formatting features fall back to the builder.