java 2c how to find the most repeated character

1private static String findMaxChar(String str) {
2    char[] array = str.toCharArray();
3    Set<Character> maxChars = new LinkedHashSet<Character>();
4
5    int maxCount = 1;
6    maxChars.add(array[0]);
7
8    for(int i = 0, j = 0; i < str.length() - 1; i = j){
9        int count = 1;
10        while (++j < str.length() && array[i] == array[j]) {
11            count++;
12        }
13        if (count > maxCount) {
14            maxCount = count;
15            maxChars.clear();
16            maxChars.add(array[i]);
17        } else if (count == maxCount) {
18            maxChars.add(array[i]);
19        }
20    }
21
22    return (maxChars + " = " + maxCount);
23}
24