Japanese calendar field names are not displayed with -Djava.locale.providers=HOST on Windows

The following program doesn't produce Japanese era, month, day names correctly with -Djava.locale.providers=HOST on Windows 7.

Locale locale = new Locale("ja","JP","JP");
SimpleDateFormat df = new SimpleDateFormat("GGGG yyyy.MMM.dd '('E')' a hh:mm:ss zzz", locale);
System.out.println(df.format(new Date()));