BigDecimal工具类处理精度计算

 /**
  * Created by My_coder on 2017-07-27.
  * 加减乘除计算工具类
  */
 public class BigDecimalUtil {
     private BigDecimalUtil() {
     }

     /**
      * 加
      */
     public static BigDecimal add(Double v1, Double v2){
         BigDecimal b1 = new BigDecimal(v1.toString());
         BigDecimal b2 = new BigDecimal(v2.toString());
         return b1.add(b2);
     }
     /**
      * 减
      */
     public static BigDecimal sub(Double v1, Double v2){
         BigDecimal b1 = new BigDecimal(v1.toString());
         BigDecimal b2 = new BigDecimal(v2.toString());
         return b1.subtract(b2);
     }
     /**
      * 乘
      */
     public static BigDecimal mul(Double v1, Double v2){
         BigDecimal b1 = new BigDecimal(v1.toString());
         BigDecimal b2 = new BigDecimal(v2.toString());
         return b1.multiply(b2);
     }
     /**
      * 除
      */
     public static BigDecimal div(Double v1, Double v2){
         BigDecimal b1 = new BigDecimal(v1.toString());
         BigDecimal b2 = new BigDecimal(v2.toString());
         //四舍五入，保留两位小数
         return b1.divide(b2,2,BigDecimal.ROUND_HALF_DOWN);
     }
 }