Javaを使用して、文字列の中で最も多くの文字と出現回数を検索しますか?

import java.util.HashMap;
import java.util.Map;

public class TestStringSum {
    public static void main(String[] args) {
        String str = "abcdefgaaabbb";
        int max = 0;
        Map map = new HashMap(str.length());
        for (char c : str.toCharArray()) {
            Integer i = map.get(c);
            int value = (i == null) ? 0 : i;
            map.put(c, ++value);
            max = value > max ? value : max;
        }
        for (Character key : map.keySet()) {
            if (map.get(key) == max) {
                System.out.println("most frequent Character => " + key + ", Count => " + max);
            }
        }
    }
}

most frequent Character => a, Count => 4
most frequent Character => b, Count => 4