Set<Entry<Producer,Price>> set = new TreeSet<>(new YourComparator);

public class toto {

    public static void main(String[] args) throws IOException {

        toto main = new toto();
        HashMap<String, Integer> map = new HashMap<String, Integer>();

        map.put("producer1", 10);
        map.put("producer2", 56);
        map.put("producer3", 32);
        map.put("producer4", 253);
        map.put("producer5", 54);
        map.put("producer6", 12);

        System.out.println(map);

        TreeSet<Entry<String, Integer>> set = new TreeSet<Entry<String, Integer>>(main.new prodpriceComparator());

        set.addAll(map.entrySet());
        System.out.println(set);
    }

    public class prodpriceComparator implements Comparator<Entry<String, Integer>> {

        @Override
        public int compare(Entry<String, Integer> p1, Entry<String, Integer> p2) {
            return p1.getValue() - p2.getValue();
        }
    }
}