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Posted to user-java@ibatis.apache.org by Perry Nguyen <pf...@hanhuy.com> on 2005/12/13 03:55:30 UTC

Interfaces for domain objects and resultMaps, how??

I have interfaces for all of my domain objects, thus, I have something 
like this contrived example:

interface Person {
   Address getAddress/setAddress
   String getName/setName
}

interface Address {
   String getStreetName/setStreetName
}

class ConcretePerson {
   // implement Person interface
}
class ConcreteAddress {
   // implement Address interface
}

Person and Address are in a 1:1 relationship.

Say I want to load the address object in a join with person, how do I do 
that?

<resultMap id="myResult" class="ConcretePerson">
   <result property="name" column="PERSON_NAME"/>
   <result property="address.streetName" column="ADDR_ST_NAME"/>
</resultMap>
<!-- using the above resultMap results in an InstantiationException 
because Address is an interface -->

<select ... resultMap="myResult">
   select p.name as person_name, a.name as addr_st_name
   from person p, address a
   where p.addr_id = a.id
</select>

Alternatively, I tried
<resultMap id="myResult" class="ConcretePerson">
   <result property="name" column="PERSON_NAME"/>
   <result property="address" resultMap="myAddrResult"/>
</resultMap>
<resultMap id="myAddrResult" class="ConcreteAddress">
   <result property="streetName" column="ADDR_ST_NAME"/>
</resultMap>

This results in an instantiation exception as well, except the exception 
occurs while attempting to populate a List for the address property.

Are there any solutions for this?  IBATIS-225 looks promising, but that 
is so far down in the list and this problem is blocking me currently...


Re: Interfaces for domain objects and resultMaps, how??

Posted by Perry Nguyen <pf...@hanhuy.com>.
Larry,

I suppose you're right, the interfaces were an anachronism from the 
older design, I think I can refactor the bean interfaces to be the bean 
classes now...

Perry Nguyen wrote:
> Well,
> 
> My situation's a bit complicated, but it has to do with abstracting what 
> I had for previous entity beans, etc.
> 
> Larry Meadors wrote:
> 
>> Why are you using interfaces for beans?

Re: Interfaces for domain objects and resultMaps, how??

Posted by Perry Nguyen <pf...@hanhuy.com>.
Well,

My situation's a bit complicated, but it has to do with abstracting what 
I had for previous entity beans, etc.

Larry Meadors wrote:
> Why are you using interfaces for beans?
> 
> Larry
> 
> 
> On 12/12/05, Perry Nguyen <pf...@hanhuy.com> wrote:
> 
>>I have interfaces for all of my domain objects, thus, I have something
>>like this contrived example:
>>
>>interface Person {
>>   Address getAddress/setAddress
>>   String getName/setName
>>}
>>
>>interface Address {
>>   String getStreetName/setStreetName
>>}
>>
>>class ConcretePerson {
>>   // implement Person interface
>>}
>>class ConcreteAddress {
>>   // implement Address interface
>>}
>>
>>Person and Address are in a 1:1 relationship.
>>
>>Say I want to load the address object in a join with person, how do I do
>>that?
>>
>><resultMap id="myResult" class="ConcretePerson">
>>   <result property="name" column="PERSON_NAME"/>
>>   <result property="address.streetName" column="ADDR_ST_NAME"/>
>></resultMap>
>><!-- using the above resultMap results in an InstantiationException
>>because Address is an interface -->
>>
>><select ... resultMap="myResult">
>>   select p.name as person_name, a.name as addr_st_name
>>   from person p, address a
>>   where p.addr_id = a.id
>></select>
>>
>>Alternatively, I tried
>><resultMap id="myResult" class="ConcretePerson">
>>   <result property="name" column="PERSON_NAME"/>
>>   <result property="address" resultMap="myAddrResult"/>
>></resultMap>
>><resultMap id="myAddrResult" class="ConcreteAddress">
>>   <result property="streetName" column="ADDR_ST_NAME"/>
>></resultMap>
>>
>>This results in an instantiation exception as well, except the exception
>>occurs while attempting to populate a List for the address property.
>>
>>Are there any solutions for this?  IBATIS-225 looks promising, but that
>>is so far down in the list and this problem is blocking me currently...
>>
>>


Re: Interfaces for domain objects and resultMaps, how??

Posted by Larry Meadors <lm...@apache.org>.
Why are you using interfaces for beans?

Larry


On 12/12/05, Perry Nguyen <pf...@hanhuy.com> wrote:
> I have interfaces for all of my domain objects, thus, I have something
> like this contrived example:
>
> interface Person {
>    Address getAddress/setAddress
>    String getName/setName
> }
>
> interface Address {
>    String getStreetName/setStreetName
> }
>
> class ConcretePerson {
>    // implement Person interface
> }
> class ConcreteAddress {
>    // implement Address interface
> }
>
> Person and Address are in a 1:1 relationship.
>
> Say I want to load the address object in a join with person, how do I do
> that?
>
> <resultMap id="myResult" class="ConcretePerson">
>    <result property="name" column="PERSON_NAME"/>
>    <result property="address.streetName" column="ADDR_ST_NAME"/>
> </resultMap>
> <!-- using the above resultMap results in an InstantiationException
> because Address is an interface -->
>
> <select ... resultMap="myResult">
>    select p.name as person_name, a.name as addr_st_name
>    from person p, address a
>    where p.addr_id = a.id
> </select>
>
> Alternatively, I tried
> <resultMap id="myResult" class="ConcretePerson">
>    <result property="name" column="PERSON_NAME"/>
>    <result property="address" resultMap="myAddrResult"/>
> </resultMap>
> <resultMap id="myAddrResult" class="ConcreteAddress">
>    <result property="streetName" column="ADDR_ST_NAME"/>
> </resultMap>
>
> This results in an instantiation exception as well, except the exception
> occurs while attempting to populate a List for the address property.
>
> Are there any solutions for this?  IBATIS-225 looks promising, but that
> is so far down in the list and this problem is blocking me currently...
>
>