Question

I have two datepickers for search parameters but i cant have the search more then a week(to much of a load on the server) so i want to check if the first date is before the second one, and if the first date and second date are less then 7 days apart. if all is correct then return a true boolean if not false.

public Calendar max = Calendar.getInstance();

public boolean checkweek(Calendar cStart, Calendar cEnd) {
    Toast.makeText(this,
            cStart.DAY_OF_MONTH + " - " + cStart.MONTH + " - " + cStart.YEAR, Toast.LENGTH_LONG).show();
    if (cEnd.after(cStart) || ((cEnd.DAY_OF_MONTH == cStart.DAY_OF_MONTH) && (cEnd.MONTH == cStart.MONTH))) {
        max.set(Calendar.YEAR, cStart.YEAR);
        max.set(Calendar.MONTH, cStart.MONTH);
        max.set(Calendar.DAY_OF_MONTH, cStart.DAY_OF_MONTH);
        max.add(Calendar.DAY_OF_MONTH, 7);
        Toast.makeText(this,
                max.DAY_OF_MONTH + " - " + max.MONTH + " - " + max.YEAR,
                Toast.LENGTH_LONG).show();
        if (cEnd.before(max)) {
            return true;
        }
        else{
            return false;
        }
    }
    else{
    return false;}
}

But it throws a null exception. im declaring the cStart and cEnd so i have no idea what it is…

Answer 1

Why not just use math for this?

cEnd.getTimeInMillis() - cStart.getTimeInMillis() > (7L * 24L * 60L * 60L * 1000L)

Or, thanks to @Sam, you can make this simpler using DateUtils.WEEK_IN_MILLIS:

cEnd.getTimeInMillis() - cStart.getTimeInMillis() > DateUtils.WEEK_IN_MILLIS

How it works: Calendar.getTime().getTime() will return a long of the milliseconds value. Just subtract them (to get the difference), then check if it’s greater than 604800000L (milliseconds in a week, per above formula).

This should provide no NullPointerException if run when cStart and cEnd are non-null.