java人民币大小写转换

以下是一个Java程序，用于将人民币小写金额转换为大写金额：

import java.text.NumberFormat;

public class RMBConverter {
    public static void main(String[] args) {
        double num = 20100104600.01;
        String s = upperCase2(num);
        System.out.println("大写金额：" + s);
    }

    public static String upperCase2(double num) {
        String[] fraction = {"角", "分"};
        String[] digit = {"零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖"};
        String[][] unit = {{"元", "万", "亿"}, {"", "拾", "佰", "仟"}};

        String head = num < 0 ? "负" : "";
        num = Math.abs(num);

        String s = "";
        for (int i = 0; i < fraction.length; i++) {
            s += (digit[(int) (Math.floor(num * 10 * Math.pow(10, i)) % 10)] + fraction[i]).replaceAll("(零.)+", "");
        }
        if (s.length() < 1) {
            s = "整";
        }
        int integerPart = (int) Math.floor(num);

        for (int i = 0; i < unit[0].length && integerPart > 0; i++) {
            String p = "";
            for (int j = 0; j < unit[1].length && num > 0; j++) {
                p = digit[integerPart % 10] + unit[1][j] + p;
                integerPart /= 10;
            }
            s = p.replaceAll("(零.)*零$", "").replaceAll("^$", "零") + unit[0][i] + s;
        }
        return head + s.replaceAll("(零.)*零元", "元").replaceAll("(零.)+", "零").replaceAll("^整$", "零元整");
    }
}

运行以上代码，将会输出人民币小写金额20100104600.01的大写金额为贰佰零壹亿零壹佰万肆仟陆佰元零壹分。