I tried to check a String input that is a valid date using the format dd/MM/yyyy like this:
String input = Scanner.nextLine();
DateTimeFormatter formater = DateTimeFormatter.ofPattern("dd/MM/yyyy");
try{
LocaleDate.parse(input, formater);
}
catch(Exception e)
But it can't check some rules below:
Leap year, February 29 days.
Common year, February 28 days.
Month 1, 3, 5, 7, 8, 10, 12, max 31 days.
Month 4, 6, 9, 11, max 30 days.
When I use input = "30/02/2022", it's legal.
I use netbeans 8.2 and jdk 1.8. Do they support some methods for checking these rules?
There are two things you need to change in your formatter:
uuuu instead of yyyy. It's easy to try the latter, but y means "year within ERA". It doesn't know whether it's BC or AD. u means "year" including ERA information.SMART. Use .withResolverStyle(ResolverStyle.STRICT) to return a strict copy of the formatter.You need to enable the strict mode of the DateTimeFormatter :
DateTimeFormatter formater = DateTimeFormatter.ofPattern("dd/MM/yyyy")
.withResolverStyle(ResolverStyle.STRICT);
LocaleDate.parse("30/02/2022, formater); will then throw an exception.