Japanese Imperial Calendar and Locale

Question

The ServeltRequest has a getLocale() method, the definition is:

Returns the preferred Locale that the client will accept content in, based on the Accept-Language header.

I wrote the following simple program:

 Locale loc = new Locale("ja", "JP", "JP");
 Calendar calendar = Calendar.getInstance(loc);
 System.out.println(calendar.get(calendar.YEAR));

It successfully shows the Japanese Imperial Calendar instead of the GregorianCalendar.

Now, my question is: how can a user set up his browser eg Chrome so that request.getLocale() will return Locale("ja", "JP", "JP") ? I tried to add the Japanese language but still I get the GregorianCalendar.

Answer 1

From the source for private static Calendar createCalendar(TimeZone zone, Locale aLocale) (the method that is called internally when you call getCalendar(locale) :

if (aLocale.hasExtensions()) {
        String caltype = aLocale.getUnicodeLocaleType("ca");
        if (caltype != null) {
            switch (caltype) {
            ...
            case "japanese":
                cal = new JapaneseImperialCalendar(zone, aLocale);
                break;
            ...
            }
        }
    }

if (cal == null) {
   ...     
   if (aLocale.getVariant() == "JP" && aLocale.getLanguage() == "ja"
                   && aLocale.getCountry() == "JP") {
            cal = new JapaneseImperialCalendar(zone, aLocale);
   } else {
            cal = new GregorianCalendar(zone, aLocale);
   }
}

As you can see in the second part, the locale needs to have country = JP, language = ja and variant = JP, ie a locale string of ja_JP_JP .

The problem is that browsers don't seem to directly support setting a country and variant in the language settings, so you might have to infer that yourself - depending on your needs:

• if the language is ja assume the country and the variant to both be JP
• use some form of geolocation to get the browser location and if the browser is in Japan set country and variant to JP
• let the user choose, ie start with just the language and let the user choose the type of calendar they want to use