null value from db query caused ibatis setProperty error

[Stan Ou <jo...@yahoo.com>]

Hi all,

I have a simple query and its result is mapped to a
Java value object (vo), pretty straight forward stuff.
 My problem is that one of my properties in my vo is a
float type (or any primitive numeric type for that
matter)
and the corresponding db column returns null from the
query.  

This acutally caused ibatis to throw an error in
com.ibatis.common.beans.ComplexBeanProbe.java on
setProperty()
{
  method.invoke(object, params);
}

Here it's trying call method setBlaBlah(float f) via
reflection and passing params (params is null, in this
case.)  Since setBlaBlah() takes in a primitive float
type, passing a null causes it to throw an error.  My
question
is has anyone run into this problem and how did you
fix it?  

My temp work around is to modify that class by first
checking if params is null.  If it's null, don't set
the property.  But this created another undesired
side-effect.  when my vo is instantiated, the float
property is initialized to 0.0, which is how Java does
things, since setBlaBlah(float f) never got called ,
now that property shows up as 0.0 instead of nothing.

Any comments/suggestions are greatly appreciatged.
Thanks.

stan

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Re: null value from db query caused ibatis setProperty error

[Larry Meadors <la...@gmail.com>]

This is not really related to iBATIS, but just a simple fact of Java -
it is not possible to represent null values in a primitive variable
unless you want to use a magic number (i.e., assume that -1 or 0.123
is null - which IMO is a very, very bad idea).

If you need null, use Float, not float.

Larry

On 7/12/05, Stan Ou <jo...@yahoo.com> wrote:
> Hi all,
> 
> I have a simple query and its result is mapped to a
> Java value object (vo), pretty straight forward stuff.
>  My problem is that one of my properties in my vo is a
> float type (or any primitive numeric type for that
> matter)
> and the corresponding db column returns null from the
> query.
> 
> This acutally caused ibatis to throw an error in
> com.ibatis.common.beans.ComplexBeanProbe.java on
> setProperty()
> {
>   method.invoke(object, params);
> }
> 
> Here it's trying call method setBlaBlah(float f) via
> reflection and passing params (params is null, in this
> case.)  Since setBlaBlah() takes in a primitive float
> type, passing a null causes it to throw an error.  My
> question
> is has anyone run into this problem and how did you
> fix it?
> 
> My temp work around is to modify that class by first
> checking if params is null.  If it's null, don't set
> the property.  But this created another undesired
> side-effect.  when my vo is instantiated, the float
> property is initialized to 0.0, which is how Java does
> things, since setBlaBlah(float f) never got called ,
> now that property shows up as 0.0 instead of nothing.
> 
> Any comments/suggestions are greatly appreciatged.
> Thanks.
> 
> stan
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>