The i18n Cookbook - recipies for a global society

 Problem:

You want a calendar that is most familiar to your Japanese users.

Solution:

The Japanese calendar is identical to the Gregorian calendar, except the year is represented by the year of the emperor's reign.  It is currently the 20th year of the Heisei emperor's reign, so the year is Heisei 20.

You can create a Japanese calendar by using icu4j .

To create a calendar object:

ULocale ul = new ULocale("ja_JP@calendar=japanese");

To format a simple date example:

ULocale ul = new ULocale("en@calendar=japanese");

DateFormat df = DateFormat.getDateInstance(DateFormat.FULL, ul);

System.out.println(df.format(new Date()));

 The result is "Friday, November 28, 20 Heisei".  If we change the ULocale to japanese the output is "平成20年11月28日金曜日"

To get the era of the current date:

//Get Japanese locale with attribute specifying japanese calendar

ULocale ul = new ULocale("ja_JP@calendar=japanese"); 

//calling getInstance using the locale bearing a calendar type will give us the appropriate locale

Calendar cal = Calendar.getInstance(ul);

//Output the era number.  This is a largely arbitrary number, but it can be used to compare

//against the static constants on Japanese Calendar

System.out.println(cal.get(JapaneseCalendar.ERA) + " Heisei era = " + JapaneseCalendar.HEISEI);