Session.find() returns List instead of Set. Why?

Justin · **Posted:** Mon Dec 08, 2003 9:15 pm

Didn't find this by searching so hoping for some guidance here:

Why does Session.find() return a java.util.List? Why not Set for example? Or Collection?

My guess is that it is more important to support multiple identical objects rather than making a point that the results are not ordered.

If all of my objects have unique identifiers, is it safe to just use:

new Set(Session.find(...))?

Thanks,
Justin

mota · **Joined:** Wed Nov 05, 2003 10:57 pm **Posts:** 96

java.util.Set is an inteface. Nothing prevents you from instantiating one of its implementations (e.g. HashSet) from a List.

mota

gavin · **Posted:** Tue Dec 09, 2003 12:19 am

The semantics of a query result set are List semantics. Ordered, may contain the same element twice...

Justin · **Posted:** Tue Dec 09, 2003 1:12 pm

I guess that's the question behind the question. What is the inherent ordering of the search results? Is it simply an arbitrarily-applied ordering depending on what order the database returns the results in?
Thanks again,
Justin

emmanuel · **Posted:** Tue Dec 09, 2003 1:45 pm

What ever it may be, guessing on that is dangerous since it's internal implementation choice and might change in the future

Justin · **Posted:** Tue Dec 09, 2003 1:50 pm

Ok. Sounds like there shouldn't be a problem returning a Collection (rather than List) from my own search API.
Thanks all :p

gavin · **Posted:** Tue Dec 09, 2003 7:50 pm

The order is not arbitrary if you have an ORDER BY clause though!