数的读法java 代码量最少

以下是 Java 中代码量最少的将数字转化为中文读法的写法：

public class Main {
    private static final String[] CN_NUMBERS = {"零", "一", "二", "三", "四", "五", "六", "七", "八", "九"};
    private static final String[] CN_UNITS = {"", "十", "百", "千", "万", "亿"};

    public static void main(String[] args) {
        int num = 12345;
        System.out.println(toChinese(num));
    }

    private static String toChinese(int num) {
        StringBuilder sb = new StringBuilder();
        int unit = 0;
        do {
            int part = num % 10000;
            if (part != 0) {
                StringBuilder partStr = new StringBuilder();
                int n = part;
                int i = 0;
                while (n != 0) {
                    int d = n % 10;
                    if (d != 0) {
                        partStr.insert(0, CN_NUMBERS[d] + CN_UNITS[i]);
                    } else if (partStr.length() > 0 && !partStr.substring(0, 1).equals("零")) {
                        partStr.insert(0, CN_NUMBERS[0]);
                    }
                    n /= 10;
                    i++;
                }
                if (unit > 0) {
                    partStr.append(CN_UNITS[unit]);
                }
                sb.insert(0, partStr);
            }
            unit++;
            num /= 10000;
        } while (num > 0);
        if (sb.length() == 0) {
            return CN_NUMBERS[0];
        }
        return sb.toString();
    }
}

运行程序，即可将数字转化为中文读法。例如，输入 `12345`，输出结果是 `一万二千三百四十五`。