Java数字金额转换为大写金额

代码：

package com.daidai.java.RMB;

public class Amount2RMB {

    public static char[] NUMBER_CHAR = "零壹贰叁肆伍陆柒捌玖".toCharArray();

    public static char[] UNIT_CHAR = "元拾佰仟万拾佰仟亿拾佰仟".toCharArray();

    /** * 将小写金额转换成大写金额(以元为单位) * @param amount 小写金额 * @return 大写金额 */
    public static String amount2RMB(int amount){
        StringBuffer retSb = new StringBuffer();
        String retStr = "";
        int length = String.valueOf(amount).length()-1;//长度
        int pos = length;//当前位置
        int posValue = 0;//当前位置对应的值
        int dividend = (int) Math.pow(10, length);//被除数
        boolean flag = false;

        if(amount<10){
            retSb.append(NUMBER_CHAR[amount]);
            retSb.append(UNIT_CHAR[pos]);
        }else{
            while(pos>0){
                posValue = amount/dividend;
                amount = amount%dividend;
                if(posValue>0){
                    if(flag && (pos!=3 && pos!=7)){
                        retSb.append(NUMBER_CHAR[0]);
                    }
                    flag=false;
                    retSb.append(NUMBER_CHAR[posValue]);
                    retSb.append(UNIT_CHAR[pos]);
                }
                if(posValue==0){
                    flag = true;
                    if(pos==4 || pos==8){
                        retSb.append(UNIT_CHAR[pos]);
                    }
                }
                pos--;
                dividend = dividend/10;
            }
            if(amount>0){
                if(flag && (pos!=3 && pos!=7)){
                    retSb.append(NUMBER_CHAR[0]);
                }
                retSb.append(NUMBER_CHAR[amount]);
            }
            retSb.append(UNIT_CHAR[0]);
        }
        retSb.append("整");

        retStr = retSb.toString().replaceAll("亿万", "亿");

        System.out.println(retStr);
        return retStr;
    }

}

输入：1000200431
输出：壹拾亿零贰拾万零肆佰叁拾壹元整