Check that an input is a Date Java

Question

Hi is there a way to check if an input is a date in Java, the date format is DD/MM/YYYY so int\int\int I have the basic check if (x != "") but I was wondering if you check that it is a date.

Now I'me getting a new error code:

try {
      date = (Date) dateFormat.parse(dateInput);
} catch (ParseException e1) {
                System.out.println("FAIL!!!!!!!!");
                JOptionPane.showMessageDialog(null, "Date entered is incorrect, please close this window and try again");
                new BookApp();
            }

The indents probably got messed in when I copied and pasted it, but when the format is wrong it works and the dialog menu pops up. But when I give 12\08\2015 it give a ClassCastError. How do I get this working?

Arnaud · Answer 1 · 2015-12-04T18:46:42.930

3

1) Create a formatter for your date pattern :

DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");

2) Try to format your String input to a date :

Date date = dateFormat.parse(input);

Now, if the input doesn't match your pattern, you get a ParseException.

edited Dec 04 '15 at 18:46

answered Dec 04 '15 at 17:37

Arnaud

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and change MMM to MM – Rustam Dec 04 '15 at 17:40
Today was hard, thanks for correcting me twice :) – Arnaud Dec 04 '15 at 17:43
hi when I add `12/08/1998` for instance it throws a `ClassCastException` but the format is correct, any idea how to stop this? – Neo Streets Dec 04 '15 at 19:11
This is another problem, you should post your code if you need to be helped on this – Arnaud Dec 04 '15 at 19:21

score 0 · Answer 2 · answered Dec 04 '15 at 18:39

You can always try to parse the date and capture if the parse was successful or not.

The SimpleDateFormat will throw an exception if the string was not parsable as a date.

public boolean isDate(String dateString) {
    try {
        SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
        return dateFormat.parse(dateString) != null;
    } catch (ParseException e) {
        return false;
    }
}

Check that an input is a Date Java

2 Answers2