加

减

乘

除

BigDecimal qtySettleTotal = qtySettleTotal.setScale(2,BigDecimal.ROUND_HALF_UP);
BigDecimal qtyYF = this.txtqtyYF.getBigDecimalValue().setScale(2,BigDecimal.ROUND_HALF_UP);
BigDecimal multiple = qtySettleTotal.divide(qtyYF,2,BigDecimal.ROUND_HALF_UP);

取余

BigDecimal qtySettleTotal = qtySettleTotal.setScale(2,BigDecimal.ROUND_HALF_UP);
BigDecimal qtyYF = this.txtqtyYF.getBigDecimalValue().setScale(2,BigDecimal.ROUND_HALF_UP);
BigDecimal multiple = qtySettleTotal.divide(qtyYF,2,BigDecimal.ROUND_HALF_UP);
BigDecimal[] results = qtySettleTotal.divideAndRemainder(qtyYF); 
// results[0]整数部分，results[1]应该是余数部分但是不知道我的为啥不对，所以我直接算出除数 - results[0] 从而得出是否能够整除
BigDecimal Remainder  = multiple.subtract(results[0]);
if(new BigDecimal("0").compareTo(Remainder) == 0){
  // 整除
}