Expected Date Calculation

Question

Hi All,
Am facing one design issue, here my requirement.
Am developing a component which calculates expected date. Considering some days in a weeks as holiday always. Input to the component is an integer and some other object[from which I want to find which days in a week are non-working days, for example I want to convey Sunday & Saturday as non-working day].
Please suggest me how can I pass this message efficiently.
My thoughts are:
1. Passing a List<Integer> which holds day numbers[sun-sat will ranges 1-7, like that]. If 2 & 5 are present then it means Tuesday & Fridays are non-working days.
2. Passing a byte. [assuming first 7 bits represents days in week]
Thanks,
GK

Answer 1

Hello,
Considering you posted that in the "Design and Patterns" section, you are concerned with the flexibility of the design with regards to requirements.
Like jschell, I suspect it's unlikely that the only days off in your scheduling are fixed-days-of-week (but now, I m' French, so I may be biased :o).
If you know that you have to support other kinds of day-off constraints, you could design an interface for objects that can tell (a method with a boolean result) whether a given day (specified as a full Date passed as an argument to the method) is off. That way, when you have to support one more "day-off" rule, you can just code a new implementation of the method.
Supporting several rules is a matter of asking each of such classes, and combine the results. For example:
public class Scheduler {
    List<DayOffRule> allRules;
    public boolean canWeWorkThatDay(Date date) {
        for (DayOffRule rule : allRules) {
            if (rule.isDayOff(date)) {
                return false;
        return true;
    ... populate rules...
public interface DayOffRule{
    public boolean isdayOff(Date date);
FixedDayOfWeekOffRule implements DayOffRule {
    public FixedDayOfWeekOffRule(DayEnum singleDayOfWeek) {...}
    public boolean isdayOff(Date date) {
USCompensateChristmasDayOffRule implements DayOffRule {
}