<class name="main.org.jboss.portlet.milestone.spring.dto.EntryValues"
      table="entryValues" >
      <id column="id" name="id">
         <generator class="increment" />
      </id>
      <property name="value" column="value" type="string" not-null="false" />
      <property name="value_bool" column="value_bool" type="boolean" not-null="false" />
      <property name="value_date" column="value_date" type="date" not-null="false" />
      <!--<property name="value_file" column="value_file" type="main.org.jboss.portlet.milestone.spring.dto.UFile" not-null="false" />-->
      <one-to-one name="value_file" class="main.org.jboss.portlet.milestone.spring.dto.UFile" cascade="save-update"/>
      <property name="selected" column="selected" type="main.org.jboss.portlet.milestone.spring.dto.Pair" not-null="false" />
      <property name="dataType" column="dataType" not-null="false"
         type="main.org.jboss.portlet.milestone.spring.dto.DataType" />
      <list name="values">
         <key column="pair_id" />
         <list-index column="pair_idx" />
         <one-to-many class="main.org.jboss.portlet.milestone.spring.dto.Pair"/>
      </list>
   </class>
   
   <class name="main.org.jboss.portlet.milestone.spring.dto.UFile" table="ufile" lazy="true">
      <id column="id" name="id">
         <generator class="foreign">
               <param name="property">entryValues</param>
           </generator>
      </id>
      <property name="fileName" column="filename" type="string" />
      <property name="contentType" column="contenttype" type="string" />
      <property name="content" column="content" type="blob" />
      <one-to-one name="entryValues" class="main.org.jboss.portlet.milestone.spring.dto.EntryValues" constrained="true"/>
   </class>

getHibernateTemplate().save(entry);

2007-05-14 09:34:05,718 FATAL [main.org.jboss.portlet.milestone.spring.persistence.EntryManager] - attempted to assign id from null one-to-one property: entryValues; nested exception is org.hibernate.id.IdentifierGenerationException: attempted to assign id from null one-to-one property: entryValues