java数字转汉字工具类详解

/**
 * Created by 33303 on 2017/7/28.
 */
import java.math.BigDecimal;

/**
 * 数字转换为汉语中人民币的大写

 *
 */
public class NumberToCN {
 /**
 * 汉语中数字大写
 */
 private static final String[] CN_UPPER_NUMBER = { "零", "壹", "贰", "叁", "肆",
  "伍", "陆", "柒", "捌", "玖" };
 /**
 * 汉语中货币单位大写，这样的设计类似于占位符
 */
 private static final String[] CN_UPPER_MONETRAY_UNIT = { "分", "角", "元",
  "拾", "佰", "仟", "万", "拾", "佰", "仟", "亿", "拾", "佰", "仟", "兆", "拾",
  "佰", "仟" };
 /**
 * 特殊字符：整
 */
 private static final String CN_FULL = "整";
 /**
 * 特殊字符：负
 */
 private static final String CN_NEGATIVE = "负";
 /**
 * 金额的精度，默认值为2
 */
 private static final int MONEY_PRECISION = 2;
 /**
 * 特殊字符：零元整
 */
 private static final String CN_ZEOR_FULL = "零元" + CN_FULL;

 /**
 * 把输入的金额转换为汉语中人民币的大写
 *
 * @param numberOfMoney
 *  输入的金额
 * @return 对应的汉语大写
 */
 public static String number2CNMontrayUnit(BigDecimal numberOfMoney) {
 StringBuffer sb = new StringBuffer();
 // -1, 0, or 1 as the value of this BigDecimal is negative, zero, or
 // positive.
 int signum = numberOfMoney.signum();
 // 零元整的情况
 if (signum == 0) {
  return CN_ZEOR_FULL;
 }
 //这里会进行金额的四舍五入
 long number = numberOfMoney.movePointRight(MONEY_PRECISION)
  .setScale(0, 4).abs().longValue();
 // 得到小数点后两位值
 long scale = number % 100;
 int numUnit = 0;
 int numIndex = 0;
 boolean getZero = false;
 // 判断最后两位数，一共有四中情况：00 = 0, 01 = 1, 10, 11
 if (!(scale > 0)) {
  numIndex = 2;
  number = number / 100;
  getZero = true;
 }
 if ((scale > 0) && (!(scale % 10 > 0))) {
  numIndex = 1;
  number = number / 10;
  getZero = true;
 }
 int zeroSize = 0;
 while (true) {
  if (number <= 0) {
  break;
  }
  // 每次获取到最后一个数
  numUnit = (int) (number % 10);
  if (numUnit > 0) {
  if ((numIndex == 9) && (zeroSize >= 3)) {
   sb.insert(0, CN_UPPER_MONETRAY_UNIT[6]);
  }
  if ((numIndex == 13) && (zeroSize >= 3)) {
   sb.insert(0, CN_UPPER_MONETRAY_UNIT[10]);
  }
  sb.insert(0, CN_UPPER_MONETRAY_UNIT[numIndex]);
  sb.insert(0, CN_UPPER_NUMBER[numUnit]);
  getZero = false;
  zeroSize = 0;
  } else {
  ++zeroSize;
  if (!(getZero)) {
   sb.insert(0, CN_UPPER_NUMBER[numUnit]);
  }
  if (numIndex == 2) {
   if (number > 0) {
   sb.insert(0, CN_UPPER_MONETRAY_UNIT[numIndex]);
   }
  } else if (((numIndex - 2) % 4 == 0) && (number % 1000 > 0)) {
   sb.insert(0, CN_UPPER_MONETRAY_UNIT[numIndex]);
  }
  getZero = true;
  }
  // 让number每次都去掉最后一个数
  number = number / 10;
  ++numIndex;
 }
 // 如果signum == -1，则说明输入的数字为负数，就在最前面追加特殊字符：负
 if (signum == -1) {
  sb.insert(0, CN_NEGATIVE);
 }
 // 输入的数字小数点后两位为"00"的情况，则要在最后追加特殊字符：整
 if (!(scale > 0)) {
  sb.append(CN_FULL);
 }
 return sb.toString();
 }

 public static void main(String[] args) {
 double money = 2020004.01;
 BigDecimal numberOfMoney = new BigDecimal(money);
 String s = NumberToCN.number2CNMontrayUnit(numberOfMoney);
 System.out.println("你输入的金额为：【"+ money +"】 #--# [" +s.toString()+"]");
 }
}