I am using the following mapping file for Department entity:
<hibernate-mapping>
<class name="com.savvion.test.Department" table="department">
<id name="dept_id" type="long" column="DEPT_ID" >
<generator class="assigned"/>
</id>

<property name="name">
<column name="NAME" />
</property>
</class>
</hibernate-mapping>

However, the following JPA API call throws a "Supertype not found" IllegalStateException:

EntityType entityType = entityManagerFactory.getMetamodel().entity(bo);
SingularAttribute attribute = entityType.getId(entityType.getIdType().getJavaType());

The Department class is a POJO.

Can someone help?