金钱数字转换成中文数值

关于中文数值表示参考链接：

https://baike.baidu.com/item/%E4%B8%AD%E6%96%87%E6%95%B0%E5%AD%97/2921705?fr=aladdin

package top.simba1949;
import java.util.*;
/**
 * 最高支持：1京 减 0.01
 *
 * 设计思路：
 * 将字符串通过小数点分割为整数部分和小数部分（小数部分取2位）
 *
 * 整数部分处理思路：
 *      数字字符串从后往前数，每8位一个单元，千百十万千百十个+单位
 *      每个单元，第三位是万位，需要特殊处理，
 *          |->如果万前面存在数字，但是万位没有数值，需要添加上万，
 *          |->如果万前面没有数值同时万没有数值，不用添加
 *
 * 小数部分处理思路：
 *      判断是否是否存在
 *          |->存在，先取第一位小数位做角，然后判断长度是否大于2，
 *          |    |->不大于等于2，直接返回
 *          |    |->大于等于2再取第二位小数做分返回
 *          |->不存在，返回`整`
 * @author anthony
 * @date 2021/1/26
 */
public class MoneyUtils {
    private static final String NUMBER_ZERO_STR = "0";
    private static final String NUMBER_ONE_STR = "1";
    private static final String NUMBER_TWO_STR = "2";
    private static final String NUMBER_THREE_STR = "3";
    private static final String NUMBER_FOUR_STR = "4";
    private static final String NUMBER_FIVE_STR = "5";
    private static final String NUMBER_SIX_STR = "6";
    private static final String NUMBER_SEVEN_STR = "7";
    private static final String NUMBER_EIGHT_STR = "8";
    private static final String NUMBER_NINE_STR = "9";
    private static final String NUMBER_POINT_STR = ".";
    private static final String DELIMITER_DECIMAL_POINT = "\\.";
    private static final String DELIMITER_COMMA = ",";
    private static final String CN_NUMBER_ZERO_STR = "零";
    private static final String CN_NUMBER_ONE_STR = "壹";
    private static final String CN_NUMBER_TWO_STR = "贰";
    private static final String CN_NUMBER_THREE_STR = "叁";
    private static final String CN_NUMBER_FOUR_STR = "肆";
    private static final String CN_NUMBER_FIVE_STR = "伍";
    private static final String CN_NUMBER_SIX_STR = "陆";
    private static final String CN_NUMBER_SEVEN_STR = "柒";
    private static final String CN_NUMBER_EIGHT_STR = "捌";
    private static final String CN_NUMBER_NINE_STR = "玖";
    private static final String CN_NUMBER_TEN_STR = "拾";
    private static final String CN_NUMBER_HUNDRED_STR = "佰";
    private static final String CN_NUMBER_THOUSAND_STR = "仟";
    private static final String CN_NUMBER_TEN_THOUSAND_STR = "万";
    private static final String CN_NUMBER_BILLION_STR = "亿";
    private static final String CN_NUMBER_TRILLION_STR = "兆";
    private static final String RMB_UNIT_YUAN = "圆";
    private static final String RMB_UNIT_JIAO = "角";
    private static final String RMB_UNIT_FEN = "分";
    private static final String NO_POINT = "整";
    /**
     * 数值与中文数字映射关系
     */
    private static Map<String, String> numberMap = new HashMap<>(16);
    /**
     * 长度与单位映射关系
     */
    private static Map<Integer, String> unitMap = new HashMap<>(16);
    /**
     * 从后往前数，每8个为单位，获取单位数值，千，百，十，万，千，百，十，一
     */
    private static Map<Integer, String> unitMap4Digits = new HashMap<>(16);
    static {
        numberMap.put(NUMBER_ZERO_STR, CN_NUMBER_ZERO_STR);
        numberMap.put(NUMBER_ONE_STR, CN_NUMBER_ONE_STR);
        numberMap.put(NUMBER_TWO_STR, CN_NUMBER_TWO_STR);
        numberMap.put(NUMBER_THREE_STR, CN_NUMBER_THREE_STR);
        numberMap.put(NUMBER_FOUR_STR, CN_NUMBER_FOUR_STR);
        numberMap.put(NUMBER_FIVE_STR, CN_NUMBER_FIVE_STR);
        numberMap.put(NUMBER_SIX_STR, CN_NUMBER_SIX_STR);
        numberMap.put(NUMBER_SEVEN_STR, CN_NUMBER_SEVEN_STR);
        numberMap.put(NUMBER_EIGHT_STR, CN_NUMBER_EIGHT_STR);
        numberMap.put(NUMBER_NINE_STR, CN_NUMBER_NINE_STR);
    }
    static {
        unitMap4Digits.put(1, "");
        unitMap4Digits.put(2, CN_NUMBER_TEN_STR);
        unitMap4Digits.put(3, CN_NUMBER_HUNDRED_STR);
        unitMap4Digits.put(4, CN_NUMBER_THOUSAND_STR);
        unitMap4Digits.put(5, CN_NUMBER_TEN_THOUSAND_STR);
        unitMap4Digits.put(6, CN_NUMBER_TEN_STR);
        unitMap4Digits.put(7, CN_NUMBER_HUNDRED_STR);
        unitMap4Digits.put(8, CN_NUMBER_THOUSAND_STR);
    }
    static {
        // 圆
        unitMap.put(1, RMB_UNIT_YUAN);
        // 亿
        unitMap.put(2, CN_NUMBER_BILLION_STR);
        // 兆
        unitMap.put(3, CN_NUMBER_TRILLION_STR);
    }
    /**
     * 钱币
     * 数字转换成中文大写
     * 目前最大支持一兆
     * @return
     */
    public static String moneyNumber2CnNumber(String original){
        if (null == original || original.trim().isEmpty()){
            return "";
        }
        // beforePoint 表示整数部分，afterPoint表示小数部分
        String beforePoint, afterPoint= "";
        String originalTrim = original.replace(" ", "").trim();
        if (originalTrim.contains(NUMBER_POINT_STR)){
            // 存在小数点
            String[] split = originalTrim.split(DELIMITER_DECIMAL_POINT);
            beforePoint = split[0].trim();
            afterPoint = split[1].trim();
        }else {
            // 不存在小数点
            beforePoint = originalTrim;
        }
        return integerDealWith(beforePoint) + decimalDealWith(afterPoint);
    }
    /**
     * 整数部分处理方式
     * @param integer
     * @return
     */
    private static String integerDealWith(String integer){
        if (null == integer || integer.trim().isEmpty()){
            return "";
        }
        // 从后往前数，每8位添加一个分割符号,
        List<String> list = new ArrayList<>();
        char[] chars = integer.trim().toCharArray();
        int j = 1;
        for (int i = chars.length - 1; i >= 0; i--) {
            list.add(String.valueOf(chars[i]));
            if (j%8 == 0){
                list.add(DELIMITER_COMMA);
            }
            j++;
        }
        Collections.reverse(list);
        // 获取带有分割符`,`的字符串
        StringBuilder builder = new StringBuilder();
        list.forEach(builder::append);
        String str = builder.toString();
        // 去掉头部逗号
        if (str.startsWith(DELIMITER_COMMA)){
            str = str.replaceFirst(DELIMITER_COMMA, "");
        }
        // 每8位分割后处理
        StringBuilder resultBuilder = new StringBuilder();
        String[] split = str.split(DELIMITER_COMMA);
        int length = split.length;
        for (int i = 0; i < length; i++) {
            resultBuilder.append(integerDealWithCoreWithUnit(split[i], unitMap.get(length - i)));
        }
        return resultBuilder.toString();
    }
    /**
     * 数字按照 `千万百万十万，万千百十个` 排序
     * @param number
     * @param unit 最后的单位
     * @return
     */
    private static String integerDealWithCoreWithUnit(String number, String unit){
        if (null == number || number.trim().isEmpty() || null == unit){
            return "";
        }
        StringBuilder builder = new StringBuilder();
        switch (number.length()){
            case 7: number = "0" + number;break;
            case 6: number = "00" + number;break;
            case 5: number = "000" + number;break;
            case 4: number = "0000" + number;break;
            case 3: number = "00000" + number;break;
            case 2: number = "000000" + number;break;
            case 1: number = "0000000" + number;break;
        }
        int length = number.length();
        int j = length;
        for (int i = 0; i < length; i++) {
            String value = String.valueOf(number.charAt(i));
            if (!NUMBER_ZERO_STR.equals(value)){
                builder.append(numberMap.get(value)).append(unitMap4Digits.get(j));
            }else {
                // 8位数，第四位数没有值但是前面有值
                if (i == 3 && builder.length() > 0){
                    builder.append(CN_NUMBER_TEN_THOUSAND_STR);
                }
            }
            j--;
        }
        // 添加最后的单位
        if (builder.length() > 0){
            builder.append(unit);
        }
        return builder.toString();
    }
    /**
     * 小数部分处理方式
     * @param decimal
     * @return
     */
    private static String decimalDealWith(String decimal){
        if (null == decimal || decimal.trim().isEmpty()){
            return NO_POINT;
        }
        // 自取两位小数
        StringBuilder builder = new StringBuilder();
        // 角
        String decimalTrim = decimal.trim();
        String tenthsNumberStr = String.valueOf(decimalTrim.charAt(0));
        if (!NUMBER_ZERO_STR.equals(tenthsNumberStr)){
            builder.append(numberMap.get(tenthsNumberStr)).append(RMB_UNIT_JIAO);
        }
        // 分
        if (decimalTrim.length() >= 2){
            String percentileNumberStr = String.valueOf(decimalTrim.charAt(1));
            if (!NUMBER_ZERO_STR.equals(percentileNumberStr)){
                builder.append(numberMap.get(percentileNumberStr)).append(RMB_UNIT_FEN);
            }
        }
        return builder.toString();
    }
    private MoneyUtils() {
    }
}