[java] Specify the date format in XMLGregorianCalendar

I want to use a Date in XMLGregorianCalendar format for sending to a web service. The web service expects information in yyyy-dd-mm format. I use the below code to create an XMLGregorianCalendar and send it to web service.

Date dob = null;
DateFormat df = new SimpleDateFormat("dd/MM/yyyy");

try {
    XMLGregorianCalendar date2;
    dob = df.parse("13/06/1983");

    GregorianCalendar c = new GregorianCalendar();
    c.setTimeInMillis(dob.getTime());
    date2 = DatatypeFactory.newInstance().newXMLGregorianCalendar(c);
    System.out.println(date2);
}
catch(DatatypeConfigurationException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
catch(ParseException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

Unfortunately I always get the date as 1983-06-13T00:00:00.000-04:00. Time is also getting included in the output. Is it possible to get only the date? Could you please help me?

Yeah Got it...

Date dob=null;
DateFormat df=new SimpleDateFormat("dd/MM/yyyy");
dob=df.parse( "13/06/1983" );
GregorianCalendar cal = new GregorianCalendar();
cal.setTime(dob);
XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance().newXMLGregorianCalendarDate(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH)+1, cal.get(Calendar.DAY_OF_MONTH), DatatypeConstants.FIELD_UNDEFINED);

This will give it in correct format.

Much simpler using only SimpleDateFormat, without passing all the parameters individual:

    String FORMATER = "yyyy-MM-dd'T'HH:mm:ss'Z'";

    DateFormat format = new SimpleDateFormat(FORMATER);

    Date date = new Date();
    XMLGregorianCalendar gDateFormatted =
        DatatypeFactory.newInstance().newXMLGregorianCalendar(format.format(date));

Full example here.

Note: This is working only to remove the last 2 fields: milliseconds and timezone or to remove the entire time component using formatter yyyy-MM-dd.

This is an easy way for any format. Just change it to required format string

XMLGregorianCalendar gregFmt = DatatypeFactory.newInstance().newXMLGregorianCalendar(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss").format(new Date()));
System.out.println(gregFmt);

you don't need to specify a "SimpleDateFormat", it's simple: You must do specify the constant "DatatypeConstants.FIELD_UNDEFINED" where you don't want to show

GregorianCalendar cal = new GregorianCalendar();
cal.setTime(new Date());
XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance().newXMLGregorianCalendarDate(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH)+1, cal.get(Calendar.DAY_OF_MONTH), DatatypeConstants.FIELD_UNDEFINED);

There isn’t really an ideal conversion, but I would like to supply a couple of options.

java.time

First, you should use LocalDate from java.time, the modern Java date and time API, for parsing and holding your date. Avoid Date and SimpleDateFormat since they have design problems and also are long outdated. The latter in particular is notoriously troublesome.

    DateTimeFormatter originalDateFormatter = DateTimeFormatter.ofPattern("dd/MM/uuuu");

    String dateString = "13/06/1983";
    LocalDate date = LocalDate.parse(dateString, originalDateFormatter);
    System.out.println(date);

The output is:

1983-06-13

Do you need to go any further? LocalDate.toString() produces the format you asked about.

Format and parse

Assuming that you do require an XMLGregorianCalendar the first and easy option for converting is:

    XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance()
            .newXMLGregorianCalendar(date.toString());
    System.out.println(xmlDate);

1983-06-13

Formatting to a string and parsing it back feels like a waste to me, but as I said, it’s easy and I don’t think that there are any surprises about the result being as expected.

Pass year, month and day of month individually

    XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance()
            .newXMLGregorianCalendarDate(date.getYear(), date.getMonthValue(),
                    date.getDayOfMonth(), DatatypeConstants.FIELD_UNDEFINED);

The result is the same as before. We need to make explicit that we don’t want a time zone offset (this is what DatatypeConstants.FIELD_UNDEFINED specifies). In case someone is wondering, both LocalDate and XMLGregorianCalendar number months the way humans do, so there is no adding or subtracting 1.

Convert through GregorianCalendar

I only show you this option because I somehow consider it the official way: convert LocalDate to ZonedDateTime, then to GregorianCalendar and finally to XMLGregorianCalendar.

    ZonedDateTime dateTime = date.atStartOfDay(ZoneOffset.UTC);
    GregorianCalendar gregCal = GregorianCalendar.from(dateTime);
    XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance()
            .newXMLGregorianCalendar(gregCal);
    xmlDate.setTime(DatatypeConstants.FIELD_UNDEFINED, DatatypeConstants.FIELD_UNDEFINED,
            DatatypeConstants.FIELD_UNDEFINED, DatatypeConstants.FIELD_UNDEFINED);
    xmlDate.setTimezone(DatatypeConstants.FIELD_UNDEFINED);

I like the conversion itself since we neither need to use strings nor need to pass individual fields (with care to do it in the right order). What I don’t like is that we have to pass a time of day and a time zone offset and then wipe out those fields manually afterwards.