java 4舍5入_java 四舍五入

importjava.math.BigDecimal;publicclassDecimal{publicstaticvoidmain(String[]args)throwsException{Doublea=2999.985;BigDecimalb=newBigDecimal(a);doublef=b.setScale(2,BigDeci...

import java.math.BigDecimal;

public class Decimal {

public static void main(String[] args) throws Exception {

Double a = 2999.985;

BigDecimal b = new BigDecimal(a);

double f = b.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();

System.out.println(f);

System.out.println(new java.math.BigDecimal(Double.toString(199999.00*0.015)).setScale(2,java.math.BigDecimal.ROUND_HALF_UP).doubleValue());

System.out.println(new java.math.BigDecimal(Double.toString(199999.00*0.015)).setScale(3,java.math.BigDecimal.ROUND_HALF_UP).doubleValue());

BigDecimal b2 = new BigDecimal(Double.toString(199999.00*0.015));

double f2 = b2.setScale(3, BigDecimal.ROUND_HALF_UP).doubleValue();

System.out.println(f2);

}

输出分别是：

2999.99

2999.98

2999.985

2999.985

求问怎样才能将199999.00*0.015的结果变为2999.99?

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