Java.util.date to XMLGregorianCalendar

java

xmlgregoriancalendar

timezone

joda-time

byAnton Shumikhin·Aug 11, 2024

To convert java.util.Date to XMLGregorianCalendar, here's a snippet using DatatypeFactory:

Date date = new Date(); // Got a hot date
GregorianCalendar gregCal = new GregorianCalendar();
gregCal.setTime(date);
XMLGregorianCalendar xmlGregCal = DatatypeFactory.newInstance().newXMLGregorianCalendar(gregCal);

Here, we first create a GregorianCalendar with your Date, then generate an XMLGregorianCalendar. This ensures a precise representation of the original java.util.Date in the XMLGregorianCalendar.

Mind the timezone: handling DST and timezones

When converting a java.util.Date to XMLGregorianCalendar, remember to handle time zones and daylight saving time. Otherwise, it's like scheduling a pizza delivery for yesterday.

TimeZone timeZone = TimeZone.getTimeZone("UTC"); // Sara from UTC, are you there?
GregorianCalendar gregCal = new GregorianCalendar(timeZone);
gregCal.setTime(date);
// Proceed with the conversion, sure of accuracy

This ensures our GregorianCalendar has the right time, come rain, come shine, or even DST.

Diving into the modern times: using java.time classes

If you're with the Java 8 (or later) cool kids, go for java.time classes, which resolve many issues of java.util classes. To convert a java.util.Date to XMLGregorianCalendar, suit up and dive into the modern approach:

Date date = new Date();
Instant instant = date.toInstant();
ZonedDateTime zonedDateTime = instant.atZone(ZoneId.systemDefault()); // dialing Earth's timezone
GregorianCalendar gregCal = GregorianCalendar.from(zonedDateTime);
XMLGregorianCalendar xmlGregCal = DatatypeFactory.newInstance().newXMLGregorianCalendar(gregCal);

With this approach, you're compliant with the time zone, and wielding a more transparent and immutable method chain.

Brewing magic with external libraries: using Joda-Time

If you're an external library lover like Joda-Time, here's a brewing potion for you:

Date date = new Date();
DateTime dateTime = new DateTime(date); // Welcome to DateTime!
XMLGregorianCalendar xmlGregCal = DatatypeFactory.newInstance()
    .newXMLGregorianCalendar(dateTime.toGregorianCalendar());

Big shout out to Nicolas Mommaerts for this exciting brew.

Universally speaking: ISO 8601 formats and interoperability

When dealing with XML dates, you want to be understood universally. Go for ISO 8601 formats. Lucky for you, java.time classes use ISO 8601 standards by default. This keeps your XMLGregorianCalendar interoperability sky high.

Dodging pitfalls: troubleshooting conversion issues

Invalid values: Double-check if Date values can be represented by XMLGregorianCalendar. Mind the limits!

Time zone fuzz: Scrutinize how the time zone of the original Date could impact the display of XMLGregorianCalendar.

Calendar quirks: Be ready for historical anomalies like leap seconds. Brush up on your Gregorian calendar trivia!

After the magic: manipulation of XMLGregorianCalendar

Now, got your XMLGregorianCalendar? Here's some fun stuff you can do:

Adjust your date: Remember xmlGregCal.setYear(), xmlGregCal.setMonth(), and others.
Format your output: Use SimpleDateFormat or java.time.format.DateTimeFormatter for your unique XMLGregorianCalendar stylings.