Converting a date string to a DateTime object using Joda Time library

java

date-time

joda-time

date-formatting

byNikita Barsukov·Oct 4, 2024

Utilize Joda Time's DateTimeFormatter to convert a string into a DateTime object. Match your string format to the right pattern and use the parseDateTime method:

// " yyyy-MM-dd" is your format with year, month, day. Just add your own.
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd");
// And let it do the magic...
DateTime dateTime = formatter.parseDateTime("2023-04-01");

The correct pattern will ensure a successful parsing resulting in a DateTime instance ready for your date-time manipulation needs.

Dealing with locales and time zones

Avoid potential time-travel inducing bugs in your global applications by considering time zones and locales:

// Be the master of time with Joda
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss")
                                            .withZone(DateTimeZone.UTC)
                                            .withLocale(Locale.US); // Change to Locale.US for burgers and freedom format
DateTime dateTime = formatter.parseDateTime("2023-04-01 12:34:56");

Thanks to .withZone() and .withLocale(), you can ensure your DateTime objects gherkin-synchronize perfectly with actual local times.

Failing gracefully when parsing

Wrap your parsing logic in a try-catch block to handle parsing errors and avoid embarrassing "Uh-oh!" moments in front of your users:

try {
    DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd");
    DateTime dateTime = formatter.parseDateTime("invalid-date"); // Don't be this guy
} catch (IllegalArgumentException e) {
    // Let's be nice and offer a second chance
    System.err.println("Error parsing the date: Looks like you've entered an alternative fact, " + e.getMessage());
}

Customizing your date song with patterns

Baffling non-standard date formats? No match for Joda Time:

DateTimeFormatter formatter = new DateTimeFormatterBuilder()
                                  .appendPattern("yyyy-MM-dd")
                                  .appendLiteral(' ')
                                  .appendPattern("HH:mm:ss")
                                  .toFormatter();
DateTime dateTime = formatter.parseDateTime("2023-04-01 23:59:59");

Flex your date and time muscles by customizing your formatter to fit even your most free-spirited patterns like a glove.

Navigating ambiguous formats

There're date string formats that are as yes-or-no as asking a cat to move over. Like 01/04/2023, which can either be MM/dd/yyyy or dd/MM/yyyy. Here's your cheat code:

DateTimeFormatter formatter = DateTimeFormat.forPattern("dd/MM/yyyy");
try {
    DateTime dateTime = formatter.parseDateTime("01/04/2023");
} catch (IllegalArgumentException e) {
    formatter = DateTimeFormat.forPattern("MM/dd/yyyy"); // Surprise, it was the other one!
    DateTime dateTime = formatter.parseDateTime("01/04/2023");
}