Simple pandigital method

public static boolean isPan(String num) {
    ArrayList<Character> chars = new ArrayList<Character>();
    for (int i = 0; i<num.length(); i++) {
        if (Integer.valueOf(Character.toString(num.charAt(i))) <= num.length()) {
            if (!chars.contains(num.charAt(i))) {
                chars.add(num.charAt(i));
            } else {
                return false;
            }
        } else {
            return false;
        }
    }
    return true;
}