XDoclet: Generate a <joined-subclass> for an Interface

MrNullPointer · **Joined:** Fri Dec 09, 2005 6:49 am **Posts:** 3

Hi,

I have the following classhierarchy :

(Interface)AdditionalData
/ \
Enquiry Contract

I have generated the hbm.xml file earlier manually and it works :

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
   PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--  This hbm.xml must create by hand, cause there is no xdoclet support for 
      joined subclasses, which are interfaces -->
<hibernate-mapping>
  <class name="de.chris.AdditionalData" table="ADDITIONALDATA"> 
    <id name="id" column="DATA_ID" type="long" unsaved-value="null">   
      <generator class="native"/>
    </id> 
    <many-to-one name="person" class="de.chris.Person" column="PERSON_ID"/>
    <joined-subclass name ="de.chris.Enquiry">
      <key column ="id" />
      <property name ="stafferName" column ="STAFFERNAME" type="string"/>
   </joined-subclass>
   <joined-subclass name ="de.chris.Contract">
      <key column ="id" />
      <property name ="price" column ="PRICE" type="long"/>
   </joined-subclass>
  </class>
</hibernate-mapping>

Now I want to migrate my example application to xdoclet. All works fine,
unless the joined subclass was not generated by xdoclet.

Now my question : Is it possible to generate a valid hbm.xml when
I have an implements-dependency, or is it necessary for xdoclet
to have an extends-dependency when I am using the @hibernate.joined-subclass tag ?

thx[/b]

esword · **Joined:** Tue Jun 07, 2005 11:36 pm **Posts:** 22

You can use xdoclet to generate a mapping file like you have shown, but only if all mappings are generated by xdoclet and generated at the same time.

So if you have a library with an entity class and a mapping file that you want to extend, xdoclet won't be able to detect the original mapping file and won't generate the one for the subclass. I believe that the new Hibernate Annottions support can handle such a situation, but I am not familiar enough with those to say how.

What I did in such a situation was have xdoclet generate the base class in my library, and I manually maintained the joined-subclass mapping file, since it only had a few fields. I then used an ant task to copy in an "include" line to the subclasses mapping file in the hibernate.xml.cfg file that xdoclet generated.

MrNullPointer · **Joined:** Fri Dec 09, 2005 6:49 am **Posts:** 3

[quote="esword"]You can use xdoclet to generate a mapping file like you have shown, but only if all mappings are generated by xdoclet and generated at the same time.

Yes that's clear, in former times I write all my hbm.xml files self, now I want do this job by xdoclet. But when I define my interface and my classes :

Code:

/**
 * @hibernate.class table="data"
 */ 
public interface AdditionalData

Code:

[
/**
* @hibernate.joined-subclass table="data"
* @hibernate.joined-subclass-key column="id"
*/
public class Enquiry implements AdditionalData

Now when I run xdoclet generation I get the AdditionalData.hbm.xml
without the subclass definitions from the class Enquiry.

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
   <class name="de.chris.AdditionalData" table="data">

      <id name="id" column="id" type="java.lang.Long">
         <generator class="native">
            <!--  
               To add non XDoclet generator parameters, create a file named 
               hibernate-generator-params-AdditionalData.xml 
               containing the additional parameters and place it in your merge dir. 
            -->
         </generator>
      </id>

      <discriminator column="type" />
      <many-to-one name="person" class="de.chris.Person" cascade="none" outer-join="auto" update="true" insert="true" column="PERSON_ID" />
      <!--
         To add non XDoclet property mappings, create a file named
         hibernate-properties-AdditionalData.xml
         containing the additional properties and place it in your merge dir.
      -->
   </class>
</hibernate-mapping>

So I wonder have I make a mistake or will xdoclet force me to implement my interface by an abstract class (e.g. AbstractAdditionalData) to have the possibility to manage my data with through hibernate.

esword · **Joined:** Tue Jun 07, 2005 11:36 pm **Posts:** 22

I believe you should be able to do it with an interface. I see two things which might be causing the problem:

1) Your joined-subclass should have a different table than your base class. So

Code:

/**
* @hibernate.joined-subclass table="Enquiry_Data"
* @hibernate.joined-subclass-key column="id"
*/

2) I'm not sure this will work, but in one case where I has something similar, I also had an "extends" parameter on the joined-subclass notation:

Code:

hibernate.joined-subclass table="MY_APP_USERS" extends="sample.StandardUser"

This was from an old version of the file that I found, and I'm not sure it worked properly, so no guarantees on that one.[/code]

MrNullPointer · **Joined:** Fri Dec 09, 2005 6:49 am **Posts:** 3

esword wrote:

I believe you should be able to do it with an interface. I see two things which might be causing the problem:

1) Your joined-subclass should have a different table than your base class. So

Code:

/**
* @hibernate.joined-subclass table="Enquiry_Data"
* @hibernate.joined-subclass-key column="id"
*/

Ohh thank you I have make a copy and paste error, cause I've try to do the mapping as a @hibernate.discriminator ... but when I change the table
to "Enquiry_Data" the generated hbm.xml file don't change.

2) I'm not sure this will work, but in one case where I has something similar, I also had an "extends" parameter on the joined-subclass notation:

Code:

hibernate.joined-subclass table="MY_APP_USERS" extends="sample.StandardUser"

This was from an old version of the file that I found, and I'm not sure it worked properly, so no guarantees on that one.[/code]

I have looked to :
http://xdoclet.sourceforge.net/xdoclet/tags/hibernate-tags.html#@hibernate_joined-subclass__0__1_
and there was no parameter "extends" and according to this it sadly don't work.

david · **Posted:** Mon Dec 12, 2005 7:08 pm

A heap of work has gone into HIbernate 3 support in XDoclet.
For example http://cvs.sourceforge.net/viewcvs.py/xdoclet/xdoclet/modules/hibernate/src/xdoclet/modules/hibernate/resources/hibernate-joined-subclass.xdt?view=markup

Shows the extends attribute is supported (in the CVS version).