Here you can find the source of sum(BigDecimal num1, BigDecimal num2, int scale)
public static BigDecimal sum(BigDecimal num1, BigDecimal num2, int scale)
//package com.java2s; //License from project: Open Source License import java.math.BigDecimal; import java.math.RoundingMode; public class Main { public static BigDecimal sum(BigDecimal num1, BigDecimal num2, int scale) { return roundBigDecimal(num1.add(num2), scale); }/*from ww w .j a v a 2 s .c om*/ public static BigDecimal sum(BigDecimal... amounts) { return sum(2, amounts); } public static BigDecimal sum(int scale, BigDecimal... amounts) { BigDecimal result = null; for (BigDecimal bigDecimal : amounts) { if (bigDecimal != null) { result = result == null ? bigDecimal : result.add(bigDecimal); } } return roundBigDecimal(result, scale); } public static BigDecimal roundBigDecimal(BigDecimal num) { return roundBigDecimal(num, 2); } public static BigDecimal roundBigDecimal(BigDecimal num, int scale) { if (num != null) { return num.setScale(scale, RoundingMode.HALF_UP); } return num; } }