Java代码
@Test
void a() {
NumberFormat format = DecimalFormat.getInstance(Locale.CHINA);
format.setMaximumFractionDigits(2);
format.setMinimumFractionDigits(2);
format.setCurrency(Currency.getInstance(Locale.CHINA));
for (RoundingMode mode : RoundingMode.values()) {
if(mode == RoundingMode.UNNECESSARY) continue;
format.setRoundingMode(mode);
System.out.println("Rounding mode: " + mode);
System.out.println("--------------------------------------------------------");
System.out.println("\t format 1.014 is " + format.format(1.014));
System.out.println("\t format 1.015 is " + format.format(1.015));
System.out.println("\t format 1.016 is " + format.format(1.016));
System.out.println();
}
}
结果:
舍入模式:UP
format 1.014 is 1.02
format 1.015 is 1.02
format 1.016 is 1.02
舍入模式:DOWN
format 1.014 is 1.01
format 1.015 is 1.01
format 1.016 is 1.01
舍入模式:CEILING
format 1.014 is 1.02
format 1.015 is 1.02
format 1.016 is 1.02
舍入模式:FLOOR
format 1.014 is 1.01
format 1.015 is 1.01
format 1.016 is 1.01
舍入模式:HALF_UP
format 1.014 is 1.01
format 1.015 is 1.01
format 1.016 is 1.02
舍入模式:HALF_DOWN
format 1.014 is 1.01
format 1.015 is 1.01
format 1.016 is 1.02
舍入模式:HALF_EVEN
format 1.014 is 1.01
format 1.015 is 1.01
format 1.016 is 1.02
流程结束,退出代码为0
那么,有没有一种简单的方法可以将1.015格式化为1.02?(JDK 12,JDK 8)
最佳答案
那是因为1.015实际上是1.0149999999999999023003738329862244427204132080078125
使用BigDecimal的解决方案适用于字符串
BigDecimal db = new BigDecimal("1.015");
db = db.setScale(2, BigDecimal.ROUND_HALF_UP);`