Make Simpledateformat.Parse() Fail on Invalid Dates (E.G. Month Is Greater Than 12)

Make SimpleDateFormat.parse() fail on invalid dates (e.g. month is greater than 12)

You need to make it non-lenient. Thus,

format.setLenient(false);

should do it.

Why does SimpleDateFormat parse incorrect date?

You should use DateFormat.setLenient(false):

SimpleDateFormat df = new SimpleDateFormat("MM/dd/yyyy");
df.setLenient(false);
df.parse("03/88/2013"); // Throws an exception

I'm not sure that will catch everything you want - I seem to remember that even with setLenient(false) it's more lenient than you might expect - but it should catch invalid month numbers for example.

I don't think it will catch trailing text, e.g. "03/01/2013 sjsjsj". You could potentially use the overload of parse which accepts a ParsePosition, then check the current parse index after parsing has completed:

ParsePosition position = new ParsePosition(0);
Date date = dateFormat.parse(text, position);
if (position.getIndex() != text.length()) {
    // Throw an exception or whatever else you want to do
}

You should also look at the Joda Time API which may well allow for a stricter interpretation - and is a generally cleaner date/time API anyway.

Make SimpleDateFormat.parse() fail on invalid dates (e.g. month is greater than 12)

You need to make it non-lenient. Thus,

format.setLenient(false);

should do it.

Weird date parsing in Java

Try this (before parsing the actual date):

sdf.setLenient(false);

See also:

• Make SimpleDateFormat.parse() fail on invalid dates (e.g. month is greater than 12)

Incorrect date parsing using SimpleDateFormat, Java

Have you tried calling setLenient(false) on your SimpleDateFormat?

import java.util.*;
import java.text.*;

public class Test {

    public static void main(String[] args) throws Exception {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        format.setLenient(false);
        Date date = format.parse("2011-06-1211"); // Throws...
        System.out.println(date);
    }
}

Note that I'd also suggest setting the time zone and locale of your SimpleDateFormat. (Alternatively, use Joda Time instead...)

validating a date using dateformat

It's by default lenient. You need to set it non-lenient before parsing.

ft.setLenient(false);

This will result in a ParseException when an invalid day and/or month is been supplied as compared to the year. Note that this doesn't validate the year itself as basically any number of years is valid. Depending on the concrete functional requirement, you might want to do an additional check on the year, e.g. split string on / and then check if the length of the 1st part is 4.

Why does SimpleDateFormat.parse accept an invalid date string?

From a glance of the javadocs, it seems to be using a lenient mode of parsing in which it accepts poorly formatted input:

Adding this line

format.setLenient(false);

after the initialization of your DateFormat object appears to fix it.

---

Related Topics