Formatting

Changing Date Format Symbols

The format method of the SimpleDateFormat class returns a String comprised of digits and symbols. For example, in the String "Friday, April 10, 1998," the symbols are "Friday" and "April." If the symbols encapsulated in SimpleDateFormat don't meet your needs, you can change them with the DateFormatSymbols class. You can change symbols that represent names for months, days of the week, and time zones, among others. The following table lists the DateFormatSymbols methods that allow you to modify the symbols:

Setter Method	Example of Symbol the Method Modifies
setAmPmStrings	PM
setEras	AD
setMonths	December
setShortMonths	Dec
setShortWeekdays	Tue
setWeekdays	Tuesday
setZoneStrings	PST

The following example invokes setShortWeekdays to change the short names of the days of the week from lower to upper case characters. The full source code for this example is in the file named DateFormatSymbolsDemo.java. The first element in the array argument of setShortWeekdays is a null String. Therefore, the array is one-based rather than zero-based. The SimpleDateFormat constructor accepts the modified DateFormatSymbols object as an argument. Here is the source code:

Date today;
String result;
SimpleDateFormat formatter;
DateFormatSymbols symbols;
String[] defaultDays;
String[] modifiedDays;

symbols = new DateFormatSymbols(new Locale("en","US"));
defaultDays = symbols.getShortWeekdays();

for (int i = 0; i < defaultDays.length; i++) {
   System.out.print(defaultDays[i] + "  ");
}
System.out.println();

String[] capitalDays = {
   "", "SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"};
symbols.setShortWeekdays(capitalDays);

modifiedDays = symbols.getShortWeekdays();
for (int i = 0; i < modifiedDays.length; i++) {
   System.out.print(modifiedDays[i] + "  ");
}

System.out.println();
System.out.println();

formatter = new SimpleDateFormat("E", symbols);
today = new Date();
result = formatter.format(today);
System.out.println(result);

The preceding code generates this output:

  Sun  Mon  Tue  Wed  Thu  Fri  Sat  
  SUN  MON  TUE  WED  THU  FRI  SAT  

WED

Formatting