我正在修改 Android 中的 BigDecimal
和货币格式,想知道是否可以使用 BigDecimal
执行以下操作:
我想要的:
64.99 --> 65.00 (Rounded Up)
64.99 --> 60.00 (Rounded Down)
65.01 --> 70.00 (Rounded Up)
65.01 --> 65.00 (Rounded Down)
目前,使用下面的代码,我只能四舍五入为零。例如:
我得到的:
64.99 --> 70.00 (Rounded Up)
64.99 --> 60.00 (Rounded Down)
65.01 --> 70.00 (Rounded Up)
65.01 --> 60.00 (Rounded Down)
有没有办法使用 BigDecimal
来实现我想要的?
我的代码:
private static void printRoundedValues() {
NumberFormat currencyFormat = NumberFormat.getCurrencyInstance();
BigDecimal valueUp = new BigDecimal(64.50, new MathContext(1,RoundingMode.UP));
BigDecimal valueDown = new BigDecimal(64.50, new MathContext(1,RoundingMode.DOWN));
System.out.println("Value Up: " + currencyFormat.format(valueUp));
System.out.println("Value Down: " + currencyFormat.format(valueDown));
}
最佳答案
您可以乘以 2
,然后四舍五入到最接近的 10
,然后除以 2
。这些 BigDecimals
的精度为 2
;对于不同比例的 BigDecimals
,它可能需要不同。
BigDecimal[] bds = {new BigDecimal("64.99"), new BigDecimal("65.01")};
BigDecimal two = new BigDecimal("2");
MathContext mcUp = new MathContext(2, RoundingMode.UP);
MathContext mcDown = new MathContext(2, RoundingMode.DOWN);
NumberFormat currency = NumberFormat.getCurrencyInstance();
for (BigDecimal bd : bds)
{
System.out.println("Test: " + bd);
BigDecimal roundUp5 = bd.multiply(two).round(mcUp).divide(two);
System.out.println("Round up: " + currency.format(roundUp5));
BigDecimal roundDown5 = bd.multiply(two).round(mcDown).divide(two);
System.out.println("Round down: " + currency.format(roundDown5));
}
输出:
Test: 64.99
Round up: $65.00
Round down: $60.00
Test: 65.01
Round up: $70.00
Round down: $65.00
关于android - BigDecimal 舍入为 0 或 5,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21887385/