Java实现将数字金额转为大写中文金额

输入数字金额参数，运行程序得到其对应的大写中文金额；例如：输入-12.56，输出-12.56: 壹拾贰元伍角陆分

Hutool工具包中也含有一个类型转换的方法，可以实现“金额的大小写”转换，但是这个工具包也有一些局限，“转换为大写只能精确到分（小数点儿后两位），之后的数字会被忽略”。参考文档：https://www.hutool.cn/docs/#/core/类型转换/类型转换工具类-Convert

/**
 * @Title: ConvertUpMoney
 * @Description: 将数字金额转为大写汉字金额
 */
public class ConvertUpMoney {

    //大写数字
    private static final String[] NUMBERS = {"零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖"};
    // 整数部分的单位
    private static final String[] IUNIT = {"元", "拾", "佰", "仟", "万", "拾", "佰", "仟", "亿", "拾", "佰", "仟", "万", "拾", "佰", "仟"};
    //小数部分的单位
    private static final String[] DUNIT = {"角", "分", "厘"};

    //转成中文的大写金额
    public static String toChinese(String str) {
        //判断输入的金额字符串是否符合要求
        if (StringUtils.isBlank(str) || !str.matches("(-)?[\\d]*(.)?[\\d]*")) {
            System.out.println("抱歉，请输入数字！");
            return str;
        }

        if ("0".equals(str) || "0.00".equals(str) || "0.0".equals(str)) {
            return "零元";
        }

        //判断是否存在负号"-"
        boolean flag = false;
        if (str.startsWith("-")) {
            flag = true;
            str = str.replaceAll("-", "");
        }

        str = str.replaceAll(",", "");//去掉","
        String integerStr;//整数部分数字
        String decimalStr;//小数部分数字

        //初始化：分离整数部分和小数部分
        if (str.indexOf(".") > 0) {
            integerStr = str.substring(0, str.indexOf("."));
            decimalStr = str.substring(str.indexOf(".") + 1);
        } else if (str.indexOf(".") == 0) {
            integerStr = "";
            decimalStr = str.substring(1);
        } else {
            integerStr = str;
            decimalStr = "";
        }

        //beyond超出计算能力，直接返回
        if (integerStr.length() > IUNIT.length) {
            System.out.println(str + "：超出计算能力");
            return str;
        }

        int[] integers = toIntArray(integerStr);//整数部分数字
        //判断整数部分是否存在输入012的情况
        if (integers.length > 1 && integers[0] == 0) {
            System.out.println("抱歉，请输入数字！");
            if (flag) {
                str = "-" + str;
            }
            return str;
        }
        boolean isWan = isWan5(integerStr);//设置万单位
        int[] decimals = toIntArray(decimalStr);//小数部分数字
        String result = getChineseInteger(integers, isWan) + getChineseDecimal(decimals);//返回最终的大写金额
        if (flag) {
            return "负" + result;//如果是负数，加上"负"
        } else {
            return result;
        }
    }

    //将字符串转为int数组
    private static int[] toIntArray(String number) {
        int[] array = new int[number.length()];
        for (int i = 0; i < number.length(); i++) {
            array[i] = Integer.parseInt(number.substring(i, i + 1));
        }
        return array;
    }

    //将整数部分转为大写的金额
    public static String getChineseInteger(int[] integers, boolean isWan) {
        StringBuffer chineseInteger = new StringBuffer("");
        int length = integers.length;
        if (length == 1 && integers[0] == 0) {
            return "";
        }
        for (int i = 0; i < length; i++) {
            String key = "";
            if (integers[i] == 0) {
                if ((length - i) == 13)//万（亿）
                    key = IUNIT[4];
                else if ((length - i) == 9) {//亿
                    key = IUNIT[8];
                } else if ((length - i) == 5 && isWan) {//万
                    key = IUNIT[4];
                } else if ((length - i) == 1) {//元
                    key = IUNIT[0];
                }
                if ((length - i) > 1 && integers[i + 1] != 0) {
                    key += NUMBERS[0];
                }
            }
            chineseInteger.append(integers[i] == 0 ? key : (NUMBERS[integers[i]] + IUNIT[length - i - 1]));
        }
        return chineseInteger.toString();
    }

    //将小数部分转为大写的金额
    private static String getChineseDecimal(int[] decimals) {
        StringBuffer chineseDecimal = new StringBuffer("");
        for (int i = 0; i < decimals.length; i++) {
            if (i == 3) {
                break;
            }
            chineseDecimal.append(decimals[i] == 0 ? "" : (NUMBERS[decimals[i]] + DUNIT[i]));
        }
        return chineseDecimal.toString();
    }

    //判断当前整数部分是否已经是达到【万】
    private static boolean isWan5(String integerStr) {
        int length = integerStr.length();
        if (length > 4) {
            String subInteger = "";
            if (length > 8) {
                subInteger = integerStr.substring(length - 8, length - 4);
            } else {
                subInteger = integerStr.substring(0, length - 4);
            }
            return Integer.parseInt(subInteger) > 0;
        } else {
            return false;
        }
    }

    //Test
    public static void main(String[] args) {
        String number = "12.56";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "1234567890563886.123";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "1600";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "156,0";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "-156,0";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "0.12";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "0.0";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "01.12";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "0125";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "-0125";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        number = "appblog666";
        System.out.println(number + ": " + ConvertUpMoney.toChinese(number));

        System.out.println(null + ": " + ConvertUpMoney.toChinese(null));
    }
}