字符串压缩

public static void strZip(String s) {
        for (int i = 0; i < s.length(); i++) {
            int sum = 0;

            for (; (i + 1 < s.length()) && (s.charAt(i) == s.charAt(i + 1)); ) {
                i++;
                sum++;
            }
            System.out.print(s.charAt(i));
            if (sum != 0) {
                System.out.print(++sum);
            }
        }
    }