Question

I am using Joda-Time to handle dates within an application and found myself perplexed.
I need to produce a date using two strings (one for the date, one for the hour of the day).

I have secured the time of day through the use of a RegEx but there are still some dates that go through my RegEx (something like 30th of february for example).

I thought about using the following DateTime construction within a try block (once the substrings are parsed)

DateTime(
    int year,
    int monthOfYear,
    int dayOfMonth,
    int hourOfDay,
    int minuteOfHour
)

and then throw my function’s Exception in the catch block, but according to the api doc, this constructor doesn’t throw the IllegalArgumentException exception I expected to catch, like some others do.

Anyone has any pointer to tell if the MoY/DoM couple form a valid one so as to be able to throw an exception ?

Answer 1

Although it’s not documented, it will throw org.joda.time.IllegalFieldValueException (a subclass of IllegalArgumentException) if the value is invalid. Sample code:

import org.joda.time.*;

public class Test {
    public static void main(String[] args) {
        DateTime dt = new DateTime(2012, 2, 30, 0, 0);
        System.out.println(dt);
    }
}

Result:

Exception in thread "main" org.joda.time.IllegalFieldValueException: Value 30 for dayOfMonth must be in the range [1,29]
    at org.joda.time.field.FieldUtils.verifyValueBounds(FieldUtils.java:235)
    at org.joda.time.chrono.BasicChronology.getDateMidnightMillis(BasicChronology.java:605)
    at org.joda.time.chrono.BasicChronology.getDateTimeMillis(BasicChronology.java:177)
    at org.joda.time.chrono.AssembledChronology.getDateTimeMillis(AssembledChronology.java:133)
    at org.joda.time.chrono.ZonedChronology.getDateTimeMillis(ZonedChronology.java:119)
    at org.joda.time.chrono.AssembledChronology.getDateTimeMillis(AssembledChronology.java:133)
    at org.joda.time.base.BaseDateTime.<init>(BaseDateTime.java:254)
    at org.joda.time.base.BaseDateTime.<init>(BaseDateTime.java:195)
    at org.joda.time.DateTime.<init>(DateTime.java:307)
    at Test.main(Test.java:6)

Obviously it would be nice if this were documented…