Sorting list problem

list.java

 public static void main(String[] args) {

        char[] aArray = {'a', 'a', 'a', 'a', 'a'};
        char[] bArray = {'b', 'b', 'b'};
        char[] cArray = {'c', 'c'};
        char[][] combinedList = {aArray, bArray, cArray};

        TreeMap<Character, Integer> map = new TreeMap<>();
        StringBuilder builder = new StringBuilder();

        for(char[] ar : combinedList) {
            for(char k : ar) {
                if(map.containsKey(k)) {
                    int count = map.get(k);
                    map.put(k, ++count);
                } else {
                    map.put(k, 1);
                }
            }
        }

        map.forEach((k, v) -> System.out.println("k: " + k + " v: " + v));

        while(!map.isEmpty()) {

            Set<Map.Entry<Character, Integer>> entrySet = map.entrySet();

            entrySet.forEach((e) -> {
                Character k = e.getKey();
                int v = e.getValue();

                builder.append(k);
                --v;
                if(v > 0) {
                    map.put(k, v);
                } else {
                    map.remove(k);
                }
            });
        }

        System.out.println(builder.toString());
    }