Java中金额计算器

package calc;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import java.math.BigDecimal;
import java.text.DecimalFormat;

/**
 * @Description 计算器
 * @author Sunny
 * @date 2018/8/2 0002
 * @param
 * @return
 */
public class CalculateDecimal {
    private  static  final Logger logger = LoggerFactory.getLogger(CalculateDecimal.class);
    private static final DecimalFormat DECIMAL_FORMAT = new DecimalFormat("0.00");
    /**
     * 对两个数进行四则运算; <strong>对于除法的运算,保留4位小数;</strong><br>
     * result = num1+num2;<br>
     * result = num1-num2;<br>
     * result = num1*num2;<br>
     * result = num1/num2;<br>
     * @param num1 第一个数;
     * @param num2 第二个数;
     * @param calcSymbol 运算符号 "+" "-" "*" "/"
     * @return BigDecimal
     * @throws Exception 计算异常;
     */
    public static BigDecimal calcNumber(String num1, String num2, String calcSymbol) {
        return calcNumber(num1, num2, calcSymbol,4);
    }
    public static BigDecimal calcNumber(Double num1, Double num2, String calcSymbol) {
        return calcNumber(num1, num2, calcSymbol,4);
    }
    public static BigDecimal calcNumber(Long num1, Long num2, String calcSymbol) {
        return calcNumber(num1, num2, calcSymbol,4);
    }
    public static BigDecimal calcNumber(int num1, int num2, String calcSymbol) {
        return calcNumber(num1, num2, calcSymbol,4);
    }

    /**
     * 对两个数进行四则运算; 自行选择保留位数;不四舍五入,直接截取;
     * result = num1+num2;<br>
     * result = num1-num2;<br>
     * result = num1*num2;<br>
     * result = num1/num2;<br>
     * @param num1 第一个数;
     * @param num2 第二个数;
     * @param calcSymbol 运算符号 "+" "-" "*" "/"
     * @param remainNum 保留多少位小数; 如果小于0,则为0;
     * @return BigDecimal
     * @throws Exception 计算异常;
     */
    public static  BigDecimal calcNumber(Object num1, Object num2, String calcSymbol,int remainNum) {
        remainNum = remainNum<0?0:remainNum;
        if (StringUtils.isEmpty(num1)||StringUtils.isEmpty(num2)) {
            return null;
        }
        try {
            BigDecimal decimal = new BigDecimal(num1.toString());
            BigDecimal decima2 = new BigDecimal(num2.toString());
            if ("+".equals(calcSymbol)) {
                return decimal.add(decima2);
            } else if ("-".equals(calcSymbol)) {
                return decimal.subtract(decima2);
            } else if ("*".equals(calcSymbol)) {
                return decimal.multiply(decima2).setScale(remainNum, BigDecimal.ROUND_DOWN);
            } else if ("/".equals(calcSymbol)) {
                if (!num2.equals("0")) {
                        return decimal.divide(decima2, remainNum,
                                BigDecimal.ROUND_DOWN);
                }else{
                    throw new ArithmeticException("/ by zero");
                }

            }
        } catch (Exception e) {
          logger.error("计算出错",e);
        }
        return null;
    }

    /**
     * 对两个数进行四则运算; 自行选择保留位数;四舍五入
     * result = num1+num2;<br>
     * result = num1-num2;<br>
     * result = num1*num2;<br>
     * result = num1/num2;<br>
     */
    public static  BigDecimal calcNumberHalfDown(Object num1, Object num2, String calcSymbol,int remainNum) {
        remainNum = remainNum<0?0:remainNum;
        if (StringUtils.isEmpty(num1)||StringUtils.isEmpty(num2)) {
            return null;
        }
        try {
            BigDecimal decimal = new BigDecimal(num1.toString());
            BigDecimal decima2 = new BigDecimal(num2.toString());
            if ("+".equals(calcSymbol)) {
                return decimal.add(decima2);
            } else if ("-".equals(calcSymbol)) {
                return decimal.subtract(decima2);
            } else if ("*".equals(calcSymbol)) {
                return decimal.multiply(decima2).setScale(remainNum, BigDecimal.ROUND_HALF_DOWN);
            } else if ("/".equals(calcSymbol)) {
                if (!num2.equals("0")) {
                    return decimal.divide(decima2, remainNum,
                            BigDecimal.ROUND_HALF_DOWN);
                }else{
                    throw new ArithmeticException("/ by zero");
                }

            }
        } catch (Exception e) {
            logger.error("计算出错",e);
        }
        return null;
    }

    public static String numberFormat(String source) {
        try {
            return DECIMAL_FORMAT.format(Double.valueOf(source));
        } catch (NumberFormatException e) {
            logger.error("##数字格式化出错{}##",e);
        }
        return source+"";
    }

    public static String numberFormat(double source) {
        try {
            return DECIMAL_FORMAT.format(source);
        } catch (NumberFormatException e) {
            logger.error("##数字格式化出错{}##",e);
        }
        return source+"";
    }

    /**
     * 将分为单位的钱格式化成元为单位（保留两位小数）
     * @param source
     * @return
     */
    public static String numberFormatCoin(double source) {
        BigDecimal  money = calcNumber(source, 100, "/", 2);
        return  numberFormat(money.doubleValue());
    }

    /**
     * 将分为单位的钱格式化成元为单位（取整数）
     * @param source
     * @return
     */
    public static String numberFormatInt(double source) {
        return calcNumber(source, 0.01, "*", 2).intValue() + "";
    }

    /**
     * 将分为单位的钱格式化成元为单位（四舍五入 ）
     * @param source
     * @return
     */
    public static String numberFormatIntHalfDown(double source) {
        return calcNumberHalfDown(source, 100, "/", 0).intValue() + "";
    }

    /**
     * 将分为单位的金额抹去小数点
     * @param source
     * @return
     */
    public static double numberDownCoin(double source) {
        BigDecimal money = new BigDecimal(source);
        return money.setScale(0, BigDecimal.ROUND_DOWN).doubleValue();
    }

    /**
     * 金额转化为大写
     * @param money
     * @return
     */
    public static String getCnMoney(Double money){
        final String UNIT = "万仟佰拾亿仟佰拾万仟佰拾元角分";
        final String DIGIT = "零壹贰叁肆伍陆柒捌玖";
        final double MAX_VALUE = 9999999999999.99D;

        if (money < 0 || money > MAX_VALUE) {
            return "参数非法!";
        }
        long l = Math.round(money * 100);
        if (l == 0) {
            return "零元整";
        }
        String strValue = l + "";
        // i用来控制数
        int i = 0;
        // j用来控制单位
        int j = UNIT.length() - strValue.length();
        String rs = "";
        boolean isZero = false;
        for (; i < strValue.length(); i++, j++) {
            char ch = strValue.charAt(i);
            if (ch == '0') {
                isZero = true;
                if (UNIT.charAt(j) == '亿' || UNIT.charAt(j) == '万'
                        || UNIT.charAt(j) == '元') {
                    rs = rs + UNIT.charAt(j);
                    isZero = false;
                }
            } else {
                if (isZero) {
                    rs = rs + "零";
                    isZero = false;
                }
                rs = rs + DIGIT.charAt(ch - '0') + UNIT.charAt(j);
            }
        }
        rs = rs.replaceAll("亿万", "亿");
        return rs;

    }

    public static void main(String[] args) {
        double testdf=0.000052;
        System.out.println(numberFormat(testdf));
        double strMul=6.0000615;
        System.out.println(numberFormat(strMul));
        double bdfScale=0.0078123457;
        System.out.println(numberFormat(bdfScale));
        double dbNumberF=1.234567891238;
        System.out.println(numberFormat(dbNumberF));
        String dbNumber="123456789.124";
        System.out.println(numberFormat(dbNumber));
        String cnMoney = getCnMoney(11002358.01);
        System.out.println(cnMoney);
    }
}

 打印结果如下：

0.00
6.00
0.01
1.23
123456789.12
壹仟壹佰万贰仟叁佰伍拾捌元零壹分