Double直接转换成BigDecimal,造成精度不准确

原因：直接将Double类型放在BigDecimal构造函数转换，造成数据变小

  Double taxRate = 0.06;
  BigDecimal decimal = new BigDecimal(taxRate);
  //0.059999999999999997779553950749686919152736663818359375
  log.info(decimal.toString());

正确做法：用BigDecimal的静态方法valueOf()进行转换

  Double taxRate = 0.06;
  BigDecimal taxRateValue = BigDecimal.valueOf(taxRate);
  //0.06
  log.info(taxRateValue.toString());