IsLenient to check if a date is valid
I want to check if the date I have set is valid or not. This is how I tried to do it:
public boolean validDate() {
return calendar.isLenient();
}
Call it like this:
Date date = new Date(36, 04, 2014);
System.out.println("Day = " + date.getDay());
System.out.println("Month = " + date.getMonth());
System.out.println("Year = " + date.getYear());
System.out.println("Is valid? = " + date.validDate());
System.out.println("Last day? = " + date.LastDayOfMonth(02));
And it returns this -
Day = 36 Month = 4 Year = 2014 Is valid? = true Last day? = false
My question is why it says it is valid even if it isn't. Also how can I check if this is a false date or not?
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A Calendar
can be either "soft" or "non-lenient". If it is in softening mode, it can take invalid values (for example, day = 36) and interpret them somehow; if it's in non-leniency mode and you try to set invalid values, an exception will be thrown (but not necessarily immediately, see this question .
isLenient
will tell you if it's Calendar
in soft or non-lenient mode, but it doesn't tell you anything about the validity of the data.
To check if the values are valid, you can try another one Calendar
in non-preferential mode. Your class has fields day
, month
and year
so you can try something like:
public boolean validDate() {
try {
Calendar tempCal = Calendar.getInstance();
tempCal.setLenient(false);
tempCal.set(Calendar.MONTH, month);
tempCal.set(Calendar.YEAR, year);
tempCal.set(Calendar.DAY_OF_MONTH, day);
tempCal.get(Calendar.MONTH);
// throws ArrayIndexOutOfBoundsException if any field is invalid; we don't care about the
// method result
return true;
} catch (ArrayIndexOutOfBoundsException | IllegalArgumentException e) {
return false;
}
}
Note that this does not affect your pitch Calendar
, which may still be in lowered mode.
EDIT: Tested now. The Javadoc says get()
throws ArrayIndexOutOfBoundsException
if any data is invalid, but I believe it might be a bug in the javadoc. I'll try to communicate this to Oracle.
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