TreeMap sort by value

Question

I want to write a comparator that will let me sort a TreeMap by value instead of the default natural ordering.

I tried something like this, but can\'t find out what

Answer 1

I know this post specifically asks for sorting a TreeMap by values, but for those of us that don't really care about implementation but do want a solution that keeps the collection sorted as elements are added, I would appreciate feedback on this TreeSet-based solution. For one, elements are not easily retrieved by key, but for the use case I had at hand (finding the n keys with the lowest values), this was not a requirement.

  TreeSet> set = new TreeSet<>(new Comparator>()
  {
    @Override
    public int compare(Map.Entry o1, Map.Entry o2)
    {
      int valueComparison = o1.getValue().compareTo(o2.getValue());
      return valueComparison == 0 ? o1.getKey().compareTo(o2.getKey()) : valueComparison;
    }
  });
  int key = 5;
  double value = 1.0;
  set.add(new AbstractMap.SimpleEntry<>(key, value));