I am fairly new to Hibernate. I'm trying to use hbm2java to generate code, and am having a problem using a 'joined-subclass'. I am using Hibernate 2.1.3. Here are my hbm files:

User.hbm.xml:

<hibernate-mapping>
<class
name="com.nathan.hibernatetest.User"
table="user"
>
<id
name="user_id"
type="integer"
column="user_id"
>
<generator class="native" />
</id>

<property
name="username"
type="java.lang.String"
column="username"
not-null="true"
length="32"
/>
</class>
</hibernate-mapping>

and Teacher.hbm.xml:

<hibernate-mapping>
<joined-subclass
name="com.nathan.hibernatetest.Teacher"
table="teacher"
extends="com.nathan.hibernatetest.User"
>

<key column="user_id"/>

<property
name="lastlogin"
type="java.sql.Timestamp"
column="lastlogin"
not-null="true"
length="8"
/>

</joined-subclass>
</hibernate-mapping>


When I run hbm2java, I get the following stack trace:

Buildfile: C:\dev\test\hibernatetest\build.xml
genwfpojos:
[hbm2java] Processing 2 files.
[hbm2java] Building hibernate objects
[hbm2java] net.sf.hibernate.MappingException: Cannot extend unmapped class com.nathan.hibernatetest.User
[hbm2java] at net.sf.hibernate.tool.hbm2java.CodeGenerator.handleClass(CodeGenerator.java:137)
[hbm2java] at net.sf.hibernate.tool.hbm2java.CodeGenerator.main(CodeGenerator.java:109)
[hbm2java] at net.sf.hibernate.tool.hbm2java.Hbm2JavaTask.processFile(Hbm2JavaTask.java:145)
[hbm2java] at net.sf.hibernate.tool.hbm2java.Hbm2JavaTask.execute(Hbm2JavaTask.java:95)
[hbm2java] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[hbm2java] at org.apache.tools.ant.Task.perform(Task.java:364)
[hbm2java] at org.apache.tools.ant.Target.execute(Target.java:341)
[hbm2java] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[hbm2java] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[hbm2java] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[hbm2java] at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:377)
[hbm2java] at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:135)
BUILD SUCCESSFUL
Total time: 1 second

If I place the Teacher joined-subclass inside the User class, it works fine. THe DTD seems to imply that I can have a joined-subclass separately from its parent class, but I can't get it to work. What am I doing wrong? Thanks in advance for your help!

Nathan

I narrowed it down to some aspect of the ant task. I created another ant task that just ran CodeGenerator directly, and that worked fine, while the Hbm2JavaTask task still failed - everything else being identical. Here are my tasks:

<target name="generatejava" depends="init">
<taskdef
name="hbm2java"
classname="net.sf.hibernate.tool.hbm2java.Hbm2JavaTask"
classpathref="class.path" />
<hbm2java classpathref="class.path">
<fileset dir="${basedir}">
<include name="src/com/nathan/hibernatetest/User.hbm.xml" />
<include name="src/com/nathan/hibernatetest/Teacher.hbm.xml" />
</fileset>
</hbm2java>
</target>

<target name="runhbm2java" depends="init">
<java dir="${basedir}"
classpathref="class.path"
classname="net.sf.hibernate.tool.hbm2java.CodeGenerator">
<arg value="src/com/nathan/hibernatetest/User.hbm.xml"/>
<arg value="src/com/nathan/hibernatetest/Teacher.hbm.xml"/>
</java>

</target>

generatejava task fails with the previously posted error. runhbm2java runs perfectly. Still no clue if I'm doing something wrong, or there is a bug in Hbm2JavaTask.

Anyway, I have switched to Hibernate 3.0 and the Eclipse plugin for generating java source, and that seems to be working, also. So I have a workaround in Hibernate2, and no problems with Hibernate3. The reason I didn't switch to Hibernate 3.0 in the first place is because the tools are an alpha release, but they seem to be working great. Problem solved. Thanks, Hibernate Team, for a great product.