Strange behavior of GregorianCalendar

[Marco Carnazzo]

Hi there.

I have this piece of code:

-------
GregorianCalendar date = new GregorianCalendar(23432, 2343244, 9433);
int day = date.get(Calendar.DATE);
int month = date.get(Calendar.MONTH);
int year = date.get(Calendar.YEAR);
System.out.println("Date: " + month + " - " + day + " - " + year);
System.out.println("Time: " + date.getTime());
-------

And the output is:

-------
Date: 1 - 26 - 218728
Time: Sun Feb 26 00:00:00 CET 218728
-------


Strange, uh?
Why isn't there an exception?
How can I validate the GregorianCalendar variable?

Thanks.

 

[vjg]

Hi there.

I have this piece of code:

-------
GregorianCalendar date = new GregorianCalendar(23432, 2343244, 9433);
int day = date.get(Calendar.DATE);
int month = date.get(Calendar.MONTH);
int year = date.get(Calendar.YEAR);
System.out.println("Date: " + month + " - " + day + " - " + year);
System.out.println("Time: " + date.getTime());
-------

And the output is:

-------
Date: 1 - 26 - 218728
Time: Sun Feb 26 00:00:00 CET 218728
-------

Strange, uh?
Why isn't there an exception?
How can I validate the GregorianCalendar variable?

Thanks.

By default, Calendar objects have the "lenient" property set to true.
This causes month and day arguments that are larger than the respective
valid values to be "rolled up". So, setting a date of 2007-13-01 will
be treated as 2008-01-01. If you create your GregorianCalendar object,
use setLenient(false) to turn off this behavior and then set your date
using set(23432, 2343244, 9433) you will get the exception messages you
expected.

- Virgil

 

[Lew]

GregorianCalendar date = new GregorianCalendar(23432, 2343244, 9433);
int day = date.get(Calendar.DATE);
int month = date.get(Calendar.MONTH);
int year = date.get(Calendar.YEAR);
System.out.println("Date: " + month + " - " + day + " - " + year);
System.out.println("Time: " + date.getTime());

n.b., Calendar.JANUARY == 0
<http://java.sun.com/j2se/1.5.0/docs/api/constant-values.html#java.util.Calendar.JANUARY>
<http://java.sun.com/j2se/1.5.0/docs/api/constant-values.html#java.util.Calendar.FEBRUARY>

(My personal favorite Calendar constant is

The result of your constructor was a perfectly valid Calendar object. Strictly
speaking, what you want to validate is the input to the constructor. (Use
vjg's advice.)

- Lew

 

[Marco Carnazzo]

n.b., Calendar.JANUARY == 0

Yes, I know, thanks. But why?

Use vjg's advice.

It works! Thanks, vjg!