BigDecimal Rounding mode

In this chapter you will learn:

What are the rounding mode for BigDecimal
Use different rounding mode to do calculation

Rounding mode for BigDecimal

static int ROUND_CEILING
Round towards positive infinity.
static int ROUND_DOWN
Round towards zero.
static int ROUND_FLOOR
Round towards negative infinity.
static int ROUND_HALF_DOWN
Round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.
static int ROUND_HALF_EVEN
Round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.
static int ROUND_HALF_UP
Round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.
static int ROUND_UNNECESSARY
No rounding is necessary.
static int ROUND_UP
Rounding mode to round away from zero.

Effect of rounding mode

The following code uses different rounding mode to do calculation.

import java.math.BigDecimal;
 /*from   ja v  a  2  s . co m*/

public class Main {
 
    public static void main(String[] args) {
        BigDecimal first = new BigDecimal(1f);
        BigDecimal second = new BigDecimal(2f);
 
        BigDecimal result1 = first.divide(second, BigDecimal.ROUND_CEILING);
        BigDecimal result2 = first.divide(second, BigDecimal.ROUND_DOWN);
        BigDecimal result3 = first.divide(second, BigDecimal.ROUND_FLOOR);
        BigDecimal result4 = first.divide(second, BigDecimal.ROUND_HALF_DOWN);
        BigDecimal result5 = first.divide(second, BigDecimal.ROUND_HALF_EVEN);
        BigDecimal result6 = first.divide(second, BigDecimal.ROUND_HALF_UP);
        BigDecimal result7 = first.divide(second, BigDecimal.ROUND_UP);
 
        System.out.println(result1);
        System.out.println(result2);
        System.out.println(result3);
        System.out.println(result4);
        System.out.println(result5);
        System.out.println(result6);
        System.out.println(result7);
 
    }
}