使用BigDecimal完成小数点后的精确位数的四舍五入

package com.ryan;import java.math.BigDecimal;class MyMath {public static double round(double num ,int scale) {BigDecimal big  = new BigDecimal(num);BigDecimal result = big.divide(new BigDecimal(1), scale, BigDecimal.ROUND_HALF_UP);return result.doubleValue();}}public class Test {public static void main(String[] args) {System.out.println("带小数的四舍五入测试" + MyMath.round(99.4567, 3)); //994.457}}