Comparator

public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map) {
    List<Map.Entry<K, V>> list = new LinkedList<>(map.entrySet());
    Collections.sort(list, new Comparator<Map.Entry<K, V>>() {
        @Override
        public int compare(Map.Entry<K, V> e1, Map.Entry<K, V> e2) {
            return (e1.getValue()).compareTo(e2.getValue());
        }
    });

    Map<K, V> result = new LinkedHashMap<>();
    for (Map.Entry<K, V> entry : list) {
        result.put(entry.getKey(), entry.getValue());
    }

    return result;
}