How to sort a HashMap in Java [duplicate]

Answer 1

Sorting HashMap by value in Java:

public class HashMapSortByValue {
    public static void main(String[] args) {

        HashMap unsortMap = new HashMap();
            unsortMap.put(5l,"B");
            unsortMap.put(8l,"A");
            unsortMap.put(2l, "D");
            unsortMap.put(7l,"C" );

            System.out.println("Before sorting......");
            System.out.println(unsortMap);

            HashMap sortedMapAsc = sortByComparator(unsortMap);
            System.out.println("After sorting......");
            System.out.println(sortedMapAsc);

    }

    public static HashMap sortByComparator(
            HashMap unsortMap) {

            List> list = new LinkedList>(
                unsortMap.entrySet());

            Collections.sort(list, new Comparator> () {
                public int compare(Map.Entry o1, Map.Entry o2) {
                    return o1.getValue().compareTo(o2.getValue());
                }
            });

            HashMap sortedMap = new LinkedHashMap();
            for (Entry entry : list) {
              sortedMap.put(entry.getKey(), entry.getValue());
            }
            return sortedMap;
          }

}