JAVA中金额该使用什么数据类型呢?

java中使用BigDecimal类型

mysql数据库中使用decimal数据类型

 
package com.bigdecimal;

import java.math.BigDecimal;
import java.math.RoundingMode;

public class Test {
    public static void main(String[] args) {
        BigDecimal num=new BigDecimal("2");
        BigDecimal num1=new BigDecimal("0.01");

        //加法
        System.out.println(num.add(num1));

        //减法
        System.out.println(num.subtract(num1));

        //乘法
        System.out.println(num.multiply(num1));

        //除法
        System.out.println(num.divide(num1, RoundingMode.HALF_UP));

        //比较两个数大小
        if (num.compareTo(num1)==-1){
            System.out.println(num+"小于"+num1);
        }else if (num.compareTo(num1)==0){
            System.out.println(num+"等于"+num1);
        }else if (num.compareTo(num1)==1){
            System.out.println(num+"大于"+num1);
        }

        //精度换算
        BigDecimal num2=new BigDecimal("4.281");

        //删除多余的小数位
        System.out.println(num2.setScale(2,BigDecimal.ROUND_DOWN));

        //直接进位
        System.out.println(num2.setScale(2,BigDecimal.ROUND_UP));

        //四舍五入
        System.out.println(num2.setScale(2,BigDecimal.ROUND_HALF_UP));

        //五舍六入
        System.out.println(num2.setScale(2,BigDecimal.ROUND_HALF_DOWN));
    }
}