[java] 10:24:10,145 ERROR HibernateDAOFactory:38 - net.sf.hibernate.MappingException: optimistic-lock attribute not supported for joined-subclass mappings: aero.timco.approval.document.Document

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
          "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
          "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
   <class name="aero.timco.approval.document.Document" table="document" optimistic-lock="none">
      <meta attribute="implements">
         aero.timco.approval.Identifiable
      </meta>
      <meta attribute="class-code">
      public Long getId() {
          return getDid();
       }

       public void setId(Long id) {
          setDid(id);
       }
       public int getNumberApprovals() {
          return approvals.size();
       }
       public int getNumberAccepted() {
         int accepted = 0;
         java.util.Iterator it = approvals.iterator();
         while(it.hasNext()) {
            if(((Approval)it.next()).getApproved() == 1) {
            accepted++;
            }
         }
         return accepted;
      }
      public int getNumberRejected() {
         int rejected = 0;
         java.util.Iterator it = approvals.iterator();
         while(it.hasNext()) {
            if(((Approval)it.next()).getApproved() == 2) {
               rejected++;
            }
         }
         return rejected;
      }
      public int getNumberPending() {
         int pending = 0;
         java.util.Iterator it = approvals.iterator();
         while(it.hasNext()) {
            if(((Approval)it.next()).getApproved() == 0) {
               pending++;
            }
         }
         return pending;
      }
      </meta>
      <meta attribute="class-code">static final long serialVersionUID = 0L;</meta>
      <id name="did" column="did" type="long">
         <generator class="native"/>
      </id>
      <timestamp column="last_updated" name="lastUpdated"/>
      <property name="name" column="name" type="string" length="50" not-null="true"/>
      <property name="description" column="description" type="text"/>
      <property name="createTime" column="create_time" type="timestamp" not-null="true"/>
      <property name="dueTime" column="due_time" type="timestamp"/>
      <!--<property name="lastUpdated" column="last_updated" type="timestamp"/>
      --><property name="submitted" column="submitted" type="boolean" not-null="true"/>
      <property name="stopOnRejection" column="stop_on_rejection" type="boolean" not-null="true"/>
      <many-to-one name="author" class="aero.timco.approval.document.User" cascade="none">
         <meta attribute="finder-method">findByAuthorID</meta>
         <column name="author_id" not-null="true"/>
      </many-to-one>
      <many-to-one name="documentType" class="aero.timco.approval.document.DocumentType" cascade="none">
         <column name="document_type_id" not-null="true"/>
      </many-to-one>
      <!-- set lazy to true when done testing and put accessors to notes in dao -->
      <set name="notes" lazy="false" inverse="true" cascade="all">
         <key column="document_id"/>
         <one-to-many class="aero.timco.approval.document.Note"/>
      </set>
      <!-- set lazy to true when done testing and put accessors to attachments in dao -->
      <set name="attachments" lazy="false" inverse="true" cascade="all">
         <key column="document_id"/>
         <one-to-many class="aero.timco.approval.document.Attachment"/>
      </set>
      <!-- set lazy to true when done testing and put accessors to attachments in dao -->
      <set name="approvals" lazy="false" inverse="true" cascade="all">
         <meta attribute="scope-field">protected</meta>
         <key column="document_id"/>
         <one-to-many class="aero.timco.approval.document.Approval"/>
      </set>
      <joined-subclass name="aero.timco.approval.document.CapexDocument" table="capex_document">
         <key column="capex_id"/>
         <property name="npv" column="npv" type="big_decimal"/>
      </joined-subclass>
   </class>
</hibernate-mapping>
<!--
   signoffs
-->