Hi guys -

I have a model, which naturally feels like it wants to look like:

Monday -> [ foo, bar, baz ]
Tuesday -> [ x, y, z]

So, from the main object you could:

Set sites = foo.getSitesFromDay(Monday)

and then sites would contain a foo, bar, and baz.

Is there a nice clean way to do this? Or do you have to:

Monday -> HolderObject1
Tuesday -> HolderObject2

and then HolderObject1 just contains a Set of Sites?

I appreciate any words of wisdom!

Cheers,

D

Sounds like a bi-directional relationship would do the trick.

For example:

public class Day {
private Set sites
public Set getSites() { return sites; }
public void setSites(Set sites) { this.sites = sites }
}

public class Site {
private Day day;
public Day getDay() { return day; }
public void setDay(Day day) {this.day = day;}

public Set getSitesFromDay() {
return getDay().getSites();
}
}

You had: foo.getSitesFromDay(Monday). It's much better to have the relationship back to Monday as part of the class. In my code, it would instead be:

foo.getSitesFromDay();

In fact, I'd actually name it something like getSiblings() so that the semantics of the name convey the object structure.

As for the Hibernate mapping, simply map the Day.getSites() as a Set (probably inverse=true) and Collection-one-to-many and map the Site.getDay() as a many-to-one. Very simple.