Sort an HashSet by two different values?

Question

I need help.

I have an HashSet with type < ResultEmployee >.

ResultEmployee contains Employee(which contains id, name, email and so on) and two member named "halfHits" and "fullHits". I iterate over a Set of employees to find Strings that .equals or .contains a string I search for. The "halfHits" and "fullHits" member Count this results.

My Output:

Mia Smith, 0 FullHits, 1 HalfHits

Maik May, 3 FullHits, 2 HalfHits

Eve Hello, 2 FullHits, 0 HalfHits

Tina Troy, 3 FullHits, 1 HalfHits

and so on...

Example Output that I want:

Maik May, 3 FullHits, 2 HalfHits

Tina Troy, 3 FullHits, 1 HalfHits

Eve Hello, 2 FullHits, 0 HalfHits

Mia Smith, 0 FullHits, 1 HalfHits

and so on...

Problem: I don't know how to sort a HashSet by two different values. I tried with Comparable, but I failed. I don't know how to do something like this. Please help me. I have no idea, how can I approach something like this. I tried something like this:

 public class SortHelper implements Comparator<ResultEmployee> {

@Override
    public int compare(ResultEmployee o1, ResultEmployee o2) {
        return ((Integer)o1.getFullHits()).compareTo((Integer)o2.getFullHits());
    }
}

But this only compares the fullHits and leave halfHits out.

Answer 1

Not sure why you have the casting and I'm guessing at the implementation of ResultEmployee, but try

public class SortHelper implements Comparator<ResultEmployee> {

    @Override
    public int compare(ResultEmployee o1, ResultEmployee o2) {
        int result =((Integer)o1.getFullHits()).compareTo((Integer)o2.getFullHits());
        if (result == 0) { // Full hits were the same
            result = ((Integer)o1.getHalfHits()).compareTo((Integer)o2.getHalfHits());
        }
        return result.
    }
}

Then

Set<ResultEmployee> set = new TreeSet<>(new SortHelper());

The set will be sorted as you insert.

In Java 8, instead of defining SortHelper you can use

 Set<ResultEmployee> set = new TreeSet<>(Comparator.comparing(ResultEmployee::getFullHits).thenComparing(Comparator.comparing(ResultEmployee::getHalfHits)));