java 金額轉換工具（元轉分/分轉元）

/** 
 * @description  金額元分之間轉換工具類 
 */  
public class AmountUtils {  
      
    /**金額為分的格式 */  
    public static final String CURRENCY_FEN_REGEX = "\\-?[0-9]+";  
      
    /**  
     * 將分為單位的轉換為元並返回金額格式的字符串 （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("金額格式有誤");  
        }  
          
        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();  
        }  
    }  
      
    /** 
     * 將分為單位的轉換為元 （除100） 
     *  
     * @param amount 
     * @return 
     * @throws Exception  
     */  
    public static String changeF2Y(String amount) throws Exception{  
        if(!amount.matches(CURRENCY_FEN_REGEX)) {  
            throw new Exception("金額格式有誤");  
        }  
        return BigDecimal.valueOf(Long.valueOf(amount)).divide(new BigDecimal(100)).toString();  
    }  
      
    /**  
     * 將元為單位的轉換為分 （乘100） 
     *  
     * @param amount 
     * @return 
     */  
    public static String changeY2F(Long amount){  
        return BigDecimal.valueOf(amount).multiply(new BigDecimal(100)).toString();  
    }  
      
    /**  
     * 將元為單位的轉換為分 替換小數點，支持以逗號區分的金額 
     *  
     * @param amount 
     * @return 
     */  
    public static String changeY2F(String amount){  
        String currency =  amount.replaceAll("\\$|\\￥|\\,", "");  //處理包含, ￥ 或者$的金額  
        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();  
    }  
      
    public static void main(String[] args) throws Exception {
        System.out.println(AmountUtils.changeF2Y("1"));
    }
}