I'm having a problem with trying to get a many-to-one mapping working. My table structures are as below:


Hibernate version: 3.0.3

Mapping documents:
IssueStatus.hmb.xml

Code:

<hibernate-mapping>
    <class name="com.tictrack.model.IssueStatus" table="ISSUE_STATUS_MASTER" schema="ANARASI">
        <id name="issueStatusId" type="integer">
            <column name="ISSUE_STATUS_ID" />
            <generator class="assigned" />
        </id>
        <property name="issueStatusDesc" type="string">
            <column name="ISSUE_STATUS_DESC" length="15" />
        </property>
        <property name="statusGroup" type="integer">
            <column name="STATUS_GROUP"/>
        </property>       
    </class>
    <query name="getAllStatus">
      from IssueStatus
    </query>         
</hibernate-mapping>

E3Environment.xml

Code:

<hibernate-mapping>
    <class name="com.tictrack.model.E3Environment" table="ENVIRONMENT_MASTER" schema="ANARASI">
        <id name="environmentId" type="integer">
            <column name="ENVIRONMENT_ID" />
            <generator class="assigned" />
        </id>
        <property name="environmentDesc" type="string">
            <column name="ENVIRONMENT_DESC" length="15" />
        </property>
    </class>
    <query name="getAllEnvironments">
      from E3Environment
    </query>   
</hibernate-mapping>

IssueStatistics.hbm.xml

Code:

<hibernate-mapping>
    <class name="com.tictrack.model.IssueStatistics"
           table="ISSUE_STAT_HISTORY" schema="ANARASI">
      
      <composite-id>
           <key-many-to-one name="issueStatus"
                     column="ISSUE_STATUS_ID"
                     class="com.tictrack.model.IssueStatus"/>       
           <key-many-to-one name="environment"
                     column="ENVIRONMENT_ID"
                     class="com.tictrack.model.E3Environment"/>       
           <key-property name="statsDate" type="date">
               <column name="STAT_DATE" not-null="true" />
           </key-property>
      </composite-id>
        <property name="issueCount" type="integer">
            <column name="ISSUE_COUNT" not-null="true" />
        </property>       
    </class> 

</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():
Session tSession = HibernateUtil.currentSession();
Query tQuery = tSession.createQuery("from IssueStatistics");
List tList = tQuery.list();
return tList;
Full stack trace of any exception that occurs:
Exception in thread "main" java.lang.ClassCastException: com.tictrack.model.IssueStatistics
at org.hibernate.loader.Loader.getKeyFromResultSet(Loader.java:726)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:284)
at org.hibernate.loader.Loader.doQuery(Loader.java:395)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:210)
at org.hibernate.loader.Loader.doList(Loader.java:1562)
at org.hibernate.loader.Loader.list(Loader.java:1545)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:271)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:840)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
at com.tictrack.dao.IssuesDAO.getIssueStats(IssuesDAO.java:195)
at E3TicketsTest.main(E3TicketsTest.java:40)
Name and version of the database you are using: Derby

The generated SQL (show_sql=true):
select issuestati0_.ISSUE_STATUS_ID as ISSUE1_, issuestati0_.ENVIRONMENT_ID as ENVIRONM2_, issuestati0_.STAT_DATE as STAT3_, issuestati0_.ISSUE_COUNT as ISSUE4_6_ from ANARASI.ISSUE_STAT_HISTORY issuestati0_
Debug level Hibernate log excerpt: DEBUG

Found the issue. Did'nt include "implements java.io.Serializable". Silly mistake huh...Thanks.

-Anand