I'm trying to convert a Japanese date string to JapaneseDate.
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("Gyy年MM月dd日")
.withChronology(JapaneseChronology.INSTANCE)
.withResolverStyle(ResolverStyle.LENIENT);
JapaneseDate d = JapaneseDate.from(formatter.parse("平成01年01月01日"));
System.out.println(d);
System.out.println(d.format(formatter));
output:
Japanese Reiwa 71-01-01
令和71年01月01日
Since "令和元年" is "2019", "令和71年01月01日" is "2089-01-01". "平成01年01月01日" must be "1989-01-01".
How can I convert it correctly?
If I change the resolver style to ResolverStyle.STRICT, it throws
java.time.format.DateTimeParseException: Text '平成01年01月01日'
could not be parsed: year, month, and day not valid for Era
If I change the resolver style to ResolverStyle.SMART, it throws
java.time.format.DateTimeParseException: Text '平成01年01月01日'
could not be parsed: Invalid YearOfEra for Era: Heisei 101
Try with this pattern:
DateTimeFormatter.ofPattern("Gy年MM月dd日")
y should be used single-handed otherwise it will be added a hundred years when it is up to 11 (cf. Javaバージョン別の改元(新元号)対応まとめ).
year 11:
JapaneseDate d = JapaneseDate.from(formatter.parse("平成11年11月01日"));
output:
Japanese Reiwa 81-11-01
令和81年11月01
year 12:
JapaneseDate d = JapaneseDate.from(formatter.parse("平成12年11月01日"));
output:
Japanese Heisei 12-11-01
平成12年11月01