How to check correct date format pattern?

Question

I am facing issue related to date format pattern. Suppose user gives wrong input like this '200000-05-16' and I have format like this mm/dd/yyyy. I want to check format in java class the input date is wrong.

How is it possible to do in java?

Maybe you can try to parse the input string and grab the exceptions? — araknoid, May 28 '15 at 13:13
Note that `mm` means **minutes**. You mean `MM/dd/yyyy` instead. `MM` means months. — Jesper, May 28 '15 at 13:47

score 7 · Accepted Answer · edited May 23 '17 at 12:14

Here is two solutions. I recommend the second one (the mkyong tutorial).

Solution 1 (Regexp)

String datePattern = "\\d{2}-\\d{2}-\\d{4}";

String date1 = "200000-05-16";
String date2 = "05-16-2000";

Boolean isDate1 = date1.matches(datePattern);
Boolean isDate2 = date2.matches(datePattern);

System.out.println(isDate1);
System.out.println(isDate2);

Output :

false
true

The pattern is not the better one because you could pass "99" as a month or a day and it will be ok. Please check this post for a good pattern : Regex to validate date format dd/mm/yyyy

Solution 2 (SimpleDateFormat)

This solution take a SimpleDateFormat to check if it is valid or not. Please check this link for a complete and great solution : http://www.mkyong.com/java/how-to-check-if-date-is-valid-in-java/

score 3 · Answer 2 · answered May 28 '15 at 13:39

3

import java.text.SimpleDateFormat;
import java.text.ParseException;
import java.util.Date;

public class TestDate {

    public static boolean isValid(String value) {
        try {
            new SimpleDateFormat("dd/mm/yyyy").parse(value);
            return true;
        } catch (ParseException e) {
            return false;
        }
    }
}

answered May 28 '15 at 13:39

Hung Tran

133
1
6

1

dd.MM.yyyy parses 10.10.08 returning 10.10.0008 / no ParseException – skay Oct 02 '19 at 09:55
2020-06-163 also pares correctly. – Sep 27 '20 at 21:57

score 1 · Answer 3 · answered May 28 '15 at 13:21

1

Try to parse it, if it fails - the format was not correct.

Keep in mind that SimpleDateFormat is not thread safe, so do not reuse the instance from several Threads.

answered May 28 '15 at 13:21

folkol

4,752
22
25

How to check correct date format pattern?

3 Answers3

Solution 1 (Regexp)

Solution 2 (SimpleDateFormat)