Unchecked call to TreeSet

Question

So, I'm trying to do something which I thought was fairly simple.
I have a very simple record class who's only members are two strings and then there are the usual set/get methods. Let us call it class Foo.
Now, I want to have a set of Foo's which keeps ordering based on first member, second member (e.g., like lastname, firstname). So, I build FooComparator which implements compare and equals. I then create my set class like this:
public class FooSet extends TreeSet {
        public FooSet() {
        super(new FooComparator());
}and I get:
FooSet.java:23: warning: [unchecked] unchecked call to TreeSet(java.util.Comparator<? super E>) as a member of the raw type java.util.TreeSet
super(new FooComparator());
FooComparator looks like this:
public class FooComparator implements Comparator, Serializable {  
        public FooComparator() {
        super();
    //impl of compare() and equals()
}My two questions are:
1) Is this warning ignorable?
2) If not, what is the correct fix?
Thanks, everyone.
Best,
Glenn

Answer 1

The warning isn't a biggie... I'm pretty sure it's because you're not using generics. So lets say your your record class is called FooRecord. If you changed your code around to this, it should be fine.
public class FooSet extends TreeSet<FooRecord> {
        public FooSet() {
            super(new FooComparator());
}There might be a cleaner way to implement this (I'm not too clear on generics) but I'm pretty sure that'll do the trick. Once you get into generics they're awesome and make things a hell of a lot easier.
-Thomas