加減乘除工具類BigDecimalUtil

場景：為毛要用BigDecimal這個類來實現加減乘除呢？我不說其他的，你去用小數乘小數，除小數就知道。話不多說，老規矩，開箱即用。

BigDecimalUtil.java

package com.mmall.util;

import java.math.BigDecimal;

/**
 * Created by 敲代碼的卡卡羅特
 */
public class BigDecimalUtil {

    private BigDecimalUtil(){

    }


    public static BigDecimal add(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.add(b2);
    }

    public static BigDecimal sub(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.subtract(b2);
    }


    public static BigDecimal mul(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.multiply(b2);
    }

    public static BigDecimal div(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.divide(b2,2,BigDecimal.ROUND_HALF_UP);//四舍五入,保留2位小數

        //除不盡的情況
    }





}