Collections.sort

Collections.sort.java

  List list = new ArrayList(wordCountMap.entrySet());
        Collections.sort(list, new Comparator<Map.Entry<Integer, Integer>>() {
            @Override
            public int compare(Map.Entry<Integer, Integer> a, Map.Entry<Integer, Integer> b) {
                return a.getValue() - b.getValue();
            }
        });
        Collections.reverse(list);