Formatting

Using Predefined Formats

The DateFormat class allows you to format dates and times with predefined styles in a locale-sensitive manner. The sections that follow demonstrate how to use the DateFormat class with a program called DateFormatDemo.java.

Dates

Formatting dates with the DateFormat class is a two-step process. First, you create a formatter with the getDateInstance method. Second, you invoke the format method, which returns a String containing the formatted date. The following example formats today's date by calling these two methods:

Date today;
String dateOut;
DateFormat dateFormatter;

dateFormatter = DateFormat.getDateInstance(DateFormat.DEFAULT,
					   currentLocale);
today = new Date();
dateOut = dateFormatter.format(today);

System.out.println(dateOut + " " + currentLocale.toString());

The output generated by this code follows. Notice that the formats of the dates vary with Locale. Since DateFormat is locale-sensitive, it takes care of the formatting details for each Locale.

9 avr 98	 fr_FR
9.4.1998	 de_DE
09-Apr-98	 en_US

The preceding code example specified the DEFAULT formatting style. The DEFAULT style is just one of the predefined formatting styles that the DateFormat class provides, as follows:

• DEFAULT
• SHORT
• MEDIUM
• LONG
• FULL

The following table shows how dates are formatted for each style with the U.S. and French locales:

Sample Date Formats

Style	U.S. Locale	French Locale
DEFAULT	10-Apr-98	10 avr 98
SHORT	4/10/98	10/04/98
MEDIUM	10-Apr-98	10 avr 98
LONG	April 10, 1998	10 avril 1998
FULL	Friday, April 10, 1998	vendredi, 10 avril 1998

Times

Date objects represent both dates and times. Formatting times with the DateFormat class is similar to formatting dates, except that you create the formatter with the getTimeInstance method, as follows:

DateFormat timeFormatter = DateFormat.getTimeInstance(
				DateFormat.DEFAULT, currentLocale);

The table that follows shows the various predefined format styles for the U.S. and German locales:

Sample Time Formats

Style	U.S. Locale	German Locale
DEFAULT	3:58:45 PM	15:58:45
SHORT	3:58 PM	15:58
MEDIUM	3:58:45 PM	15:58:45
LONG	3:58:45 PM PDT	15:58:45 GMT+02:00
FULL	3:58:45 oclock PM PDT	15.58 Uhr GMT+02:00

Both Dates and Times

To display a date and time in the same String, create the formatter with the getDateTimeInstance method. The first parameter is the date style, and the second is the time style. The third parameter is the Locale . Here's a quick example:

DateFormat formatter = DateFormat.getDateTimeInstance(
			DateFormat.LONG, DateFormat.LONG, currentLocale);

The following table shows the date and time formatting styles for the U.S. and French locales:

Sample Date and Time Formats

Style	U.S. Locale	French Locale
DEFAULT	25-Jun-98 1:32:19 PM	25 jun 98 22:32:20
SHORT	6/25/98 1:32 PM	25/06/98 22:32
MEDIUM	25-Jun-98 1:32:19 PM	25 jun 98 22:32:20
LONG	June 25, 1998 1:32:19 PM PDT	25 juin 1998 22:32:20 GMT+02:00
FULL	Thursday, June 25, 1998 1:32:19 o'clock PM PDT	jeudi, 25 juin 1998 22 h 32 GMT+02:00

Formatting