javasortinghashmapentryset

How to get the 3 highest values in a HashMap?

I have a hashmap which is the following:

    HashMap<String, Integer> hm = new HashMap<String, Integer>;
    hm.put("a", 1);
    hm.put("b", 12);
    hm.put("c", 53);
    hm.put("d", 2);
    hm.put("e", 17);
    hm.put("f", 8);
    hm.put("g", 8);

How would I get the keys which have the 3 highest values? So it would return:

    "c", "e", "b"

Thanks.

Solution

  • My solution, sort by values and get top 3 and return key list.

    List<String> keys = hm.entrySet().stream().sorted(Map.Entry.<String, Integer>comparingByValue().reversed()).limit(3).map(Map.Entry::getKey).collect(Collectors.toList());

    Hope it helps