Java Reference
In-Depth Information
The Date for Germany:
In FULL is Montag, 27. Juni 2011
In LONG is 27. Juni 2011
In MEDIUM is 27.06.2011
In SHORT is 27.06.11
The Date for France:
In FULL is lundi 27 juin 2011
In LONG is 27 juin 2011
In MEDIUM is 27 juin 2011
In SHORT is 27/06/11
How It Works
By statically importing the constants from the
Locale
and
DateFormat
classes, you obviate the need to
qualify the constants in the program and thus make the code a little less cluttered. The nested
Styles
enum defines the four possible styles. The program creates a
Date
object for the current date and time
and an array of
Locale
objects for four countries using values defined in the
Locale
class.
The output is produced in the nested
for
loops. The outer loop iterates over the countries, and the inner
loop is a collection-based for loop that iterates over the styles for each country in the
Styles
enum. The
ordinal()
method for an enum value returns the ordinal for the value in the enumeration. You use this
to specify the style as the first argument to the
getDateInstance()
method. A
DateFormat
object is
created for each style and country combination. Calling the
format()
method for the
DateFormat
object
produces the date string in the inner call to
println()
.
You could change the program in a couple ways. You could initialize the
locales[]
array with
DateFormat.getAvailableLocales()
. This returns an array of type
Locale
containing all of the sup-
ported locales, but be warned — there are a lot of them. You may find that the characters won't display
for some countries because your machine doesn't support the country-specific character set. You could
also use the method
getTimeInstance()
or
getDateTimeInstance()
instead of
getDateInstance()
to see what sort of output they generate.
Under the covers, a
DateFormat
object contains a
DateFormatSymbols
object that contains all the
strings for the names of days of the week and other fixed information related to time and dates. This class
is also in the
java.text
package. Normally you don't use the
DateFormatSymbols
class directly, but it
can be useful when all you want are the days of the week.
Obtaining a Date Object from a String
The
parse()
method for a
DateFormat
object interprets a
String
object argument as a date and time, and
returns a
Date
object corresponding to the date and the time. The
parse()
method throws a
ParseExcep-
tion
if the
String
object can't be converted to a
Date
object, so you must call it within a
try
block.
The
String
argument to the
parse()
method must correspond to the country and style that you used
when you obtained the
DateFormat
object. For example, the following code parses the string properly:
Date aDate;
DateFormat fmt = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
try {
aDate = fmt.parse("Saturday, July 4, 1998 ");
System.out.println("The Date string is: " + fmt.format(aDate));
