算法：输入数字，将其转换为中文。该如何解决

private static final String[] digits = new String[]{" 零", "壹", "贰", "叁",            "肆", "伍", "陆", "柒", "捌", "玖"};private static final String[] radices = new String[]{"", "拾", "佰", "仟"};private static final String[] bigRadices = new String[]{"", "万", "亿", "万"};   /**     * 算法：输入数字，将其转换为中文。     *      * @param num     *            数字字符串     * @return 转换结果(中文)     */    public static String covnt(String num)    {        String integral = num; // 整数部分        String outputCharacters = ""; // 最终转换输出结果        String d = null;        int zeroCount = 0, p = 0, quotient = 0, modulus = 0;        for (int i = 0; i < integral.length(); i++)        {            p = integral.length() - i - 1;            d = integral.substring(i, i + 1);            quotient = p / 4;            modulus = p % 4;            if (d.equals("0"))            {                zeroCount++;            }            else            {                if (zeroCount > 0)                {                    outputCharacters += digits[0];                }                zeroCount = 0;                outputCharacters += digits[Integer.parseInt(d)]                        + radices[modulus];            }            if (modulus == 0 && zeroCount < 4)            {                outputCharacters += bigRadices[quotient];            }        }        return outputCharacters;    }