验证统一社会信用代码-JAVA

private boolean isValid(String businessCode) {
        if ((businessCode.equals("")) || businessCode.length() != 18) {
            return false;
        }
        String baseCode = "0123456789ABCDEFGHJKLMNPQRTUWXY";
        char[] baseCodeArray = baseCode.toCharArray();
        Map codes = new HashMap();
        for (int i = 0; i < baseCode.length(); i++) {
            codes.put(baseCodeArray[i], i);
        }
        char[] businessCodeArray = businessCode.toCharArray();
        Character check = businessCodeArray[17];
        if (baseCode.indexOf(check) == -1) {
            return false;
        }
        int[] wi = { 1, 3, 9, 27, 19, 26, 16, 17, 20, 29, 25, 13, 8, 24, 10, 30, 28 };
        int sum = 0;
        for (int i = 0; i < 17; i++) {
            Character key = businessCodeArray[i];
            if (baseCode.indexOf(key) == -1) {
                return false;
            }
            sum += (codes.get(key) * wi[i]);
        }
        int value = 31 - sum % 31;
        return value == codes.get(check);
    }