金额元分之间转换工具类

/** 3  * @description  金额元分之间转换工具类 6  */
public class AmountUtils {

    /**金额为分的格式 */
    public static final String CURRENCY_FEN_REGEX = "\-?[0-9]+";

    /**
     * 将分为单位的转换为元并返回金额格式的字符串 （除100）
     *
     * @param amount
     * @return
     * @throws Exception
     */
    public static String changeF2Y(Long amount) throws Exception{
        if(!amount.toString().matches(CURRENCY_FEN_REGEX)) {
            throw new Exception("金额格式有误");
        }

        int flag = 0;
        String amString = amount.toString();
        if(amString.charAt(0)=='-'){
            flag = 1;
            amString = amString.substring(1);
        }
        StringBuffer result = new StringBuffer();
        if(amString.length()==1){
            result.append("0.0").append(amString);
        }else if(amString.length() == 2){
            result.append("0.").append(amString);
        }else{
            String intString = amString.substring(0,amString.length()-2);
            for(int i=1; i<=intString.length();i++){
                if( (i-1)%3 == 0 && i !=1){
                    result.append(",");
                }
                result.append(intString.substring(intString.length()-i,intString.length()-i+1));
            }
            result.reverse().append(".").append(amString.substring(amString.length()-2));
        }
        if(flag == 1){
            return "-"+result.toString();
        }else{
            return result.toString();
        }
    }

    /**
     * 将分为单位的转换为元 （除100）
     *
     * @param amount
     * @return
     * @throws Exception
     */
    public static String changeF2Y(String amount) throws Exception{
        if(!amount.matches(CURRENCY_FEN_REGEX)) {
            throw new Exception("金额格式有误");
        }
        return BigDecimal.valueOf(Long.parseLong(amount)).divide(new BigDecimal(100)).toString();
    }

    /**
     * 将元为单位的转换为分 （乘100）
     *
     * @param amount
     * @return
     */
    public static String changeY2F(Long amount){
        return BigDecimal.valueOf(amount).multiply(new BigDecimal(100)).toString();
    }

    /**
     * 将元为单位的转换为分 替换小数点，支持以逗号区分的金额
     *
     * @param amount
     * @return
     */
    public static String changeY2F(String amount){
        String currency =  amount.replaceAll("\$|\￥|\,", "");  //处理包含, ￥ 或者$的金额
        int index = currency.indexOf(".");
        int length = currency.length();
        Long amLong = 0l;
        if(index == -1){
            amLong = Long.valueOf(currency+"00");
        }else if(length - index >= 3){
            amLong = Long.valueOf((currency.substring(0, index+3)).replace(".", ""));
        }else if(length - index == 2){
            amLong = Long.valueOf((currency.substring(0, index+2)).replace(".", "")+0);
        }else{
            amLong = Long.valueOf((currency.substring(0, index+1)).replace(".", "")+"00");
        }
        return amLong.toString();
    }

}