为什么java.math.RoundingMode不带有HALF_ODD舍入？

Question

java.math.RoundingMode comes with HALF_EVEN mode which rounds number to nearest even neighbour in the case of equidistant, but why doesn't it come with HALF_ODD mode?

What is the simplest way of implementing HALF_ODD rounding in Java?

Answer 1

I hope this link can help you.

The solution proposed is:

public static int RoundToNearestRoundHalfToOdd(decimal value)
{
    // First round half toward positive infinity. Then if the fraction
    // part of the original value is 0.5 and the result of rounding is
    // even, then subtract one.
    var temp = (int)Math.Floor(value + 0.5m);
    if (value - Math.Floor(value) == 0.5m && temp % 2 == 0)
        temp -= 1;
    return temp;
}

It's in C# but I guess you can convert it for Java.

Also to help with your task, you can see the source code for the method BigDecimal#divideAndRound in the Java SDK where everything is happening.