1.保留两位小数不进位

public static void main(String[] args) {
        BigDecimal bigDecimal1 = new BigDecimal("1234.8888");
        String bigDecimal1s = bigDecimal1.setScale(2, RoundingMode.DOWN).toPlainString();
        System.out.println(bigDecimal1s);
    }

结果：

2.比较大小

if (cspMarketOrderInfoPayment.getConfirmMoney() == null || cspMarketOrderInfoPayment.getConfirmMoney().compareTo(BigDecimal.ZERO) <= 0) {
            throw new CustomException("收款金额需要大于0！");
        }
        
if (bean.getOqty().compareTo(BigDecimal.ZERO) > 0) {
                    throw new CustomException("该商品实际有库存或商品正在出库中，不允许对 商品名称、外部商品编码、最小单位的规格描述、副单位的规格描述、副单位启用状态 进行修改！");
                }

3.集合遍历+结果相加

List<CspInventoryInfo> allocationDetailsList = inventoryInfoMapper.selectInventoryAllocationDetailsByLotid(lotid);
        BigDecimal oqtyNum = allocationDetailsList.stream()
                .filter(i -> i.getOqty() != null)
                .map(CspInventoryInfo::getOqty)
                .reduce(BigDecimal.ZERO, BigDecimal::add);

4.向上取整保留4位小数（最后一位会进一）

public static void main(String[] args) {
        BigDecimal reviewRate = new BigDecimal("0.0000");
        reviewRate = new BigDecimal("123")
                .divide(new BigDecimal("9999"), 4, BigDecimal.ROUND_UP);
//        BigDecimal bigDecimal = reviewRate.setScale(2, BigDecimal.ROUND_DOWN);
        System.out.println(reviewRate);
    }


complaintRate = new BigDecimal(String.valueOf(workOrderNumber)).divide(new BigDecimal(String.valueOf(orderInfoNumber)), 10, BigDecimal.ROUND_DOWN)
                        .multiply(new BigDecimal("100"));
                dataCockpitWorkOrderResult.setComplaintSummaryRate(complaintRate.setScale(5, BigDecimal.ROUND_UP));

5.除法+乘法

BigDecimal targetReachValue = temperatureCoverageRate.divide(targetValue, 4, BigDecimal.ROUND_UP).multiply(new BigDecimal("100"));