src/main/java/com/rockagen/commons/util/Arith.java
public static double mul(final double v1,final double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.multiply(b2).doubleValue();
    }
public static double mul(final double v1,final double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.multiply(b2).doubleValue();
    }
mul
@param v1 left value
@param v2 right value
@return v1*v2