小编Mar*_*eld的帖子

我写这个是为了测试BigDecimal,但发现RoundingMode.UNNECESSARY引发了异常.有谁能解释为什么？

public class TestRounding2 {

    public static void main(String args[]) {

        Locale swedish = new Locale("sv", "SE");
        BigDecimal pp; //declare variable pp=pounds pence

        NumberFormat swedishFormat = NumberFormat.getCurrencyInstance(swedish);

        Scanner scan = new Scanner(System.in);
        System.out.println("ENTER POUNDS AND PENCE TO AT LEAST FIVE DECIMAL PLACES :");

        pp = scan.nextBigDecimal();

        BigDecimal pp1 = pp.setScale(2, RoundingMode.HALF_EVEN);
        System.out.println("HALF_EVEN: £ " + pp1.toString());
        System.out.println(swedishFormat.format(pp1));

        BigDecimal pp2 = pp.setScale(2, RoundingMode.FLOOR);
        System.out.println("FLOOR: £ " + pp2.toString());
        System.out.println(swedishFormat.format(pp2));

        BigDecimal pp3 = pp.setScale(2, RoundingMode.CEILING);
        System.out.println("CEILING £: " …