Hi all!

I create an assignment to mCompany, and test that mCompany has that assignment. So this one passes:

assertTrue("Company should have the assigment", contain(assignment,
mCompany.getAssignments()));

But not this one:
assertTrue("Company should have the assigment", mCompany.getAssignments().contains(assignment));

contain(..., ...) is simple as:

private boolean contain(Assignment a, Set s) {
Iterator i = s.iterator();
while (i.hasNext()) {
Assignment b = (Assignment) i.next();
if (b.equals(a))
return true;
}
return false;
}

And Assignment has both equals(...) and hashCode(). Why HashSet.contains(...) returns false but I can find it when iterating through the set?!

Please help!

Elixir

does your hashCode value change after it's added to the collection? I suspect it does, in that case the contains method on the HashSet loses the reference to it and can't find it. See http://www.hibernate.org/109.html and http://forum.hibernate.org/viewtopic.php?t=928172 for more information.

Thanks, that solved my problem. It seems that HashSet does not use equals(...) to check if a object is in the set - even though Java 1.4.2 documents say:

contains:
Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an element e such that (o==null ? e==null : o.equals(e)).

Your objects have to obey the hashCode/equals contract of course.