Treeset.contains() problem

Question

So I\'ve been struggling with a problem for a while now, figured I might as well ask for help here.

I\'m adding Ticket objects to a TreeSet, Ticket implements Comparable

Answer 1

This could happen if your compareTo method isn't consistent. I.e. if a.compareTo(b) > 0, then b.compareTo(a) must be < 0. And if a.compareTo(b) > 0 and b.compareTo(c) > 0, then a.compareTo(c) must be > 0. If those aren't true, TreeSet can get all confused.