• To execute queries and organize retrieved data into a JRDataSource implementation. This happens when the createDatasource() is called.
• To cancel a running query, if the user decides to interrupt that query. For doing this, the cancelQuery() method should be called.
• To close resources kept open during the data source iteration, if they are no more necessary. Resource closing is handled via the close() method.

  <queryString language="hql">
    <![CDATA[from Address address where city not in ($P{CityFilter}) order by $P!{OrderClause}]] >
  </queryString>

• public Object[] getBuiltinParameters(); - retrieves the built-in parameters associated with the query type.
• public JRQueryExecuter createQueryExecuter(JRDataset dataset, Map parameters) throws JRException; - creates the query executer implementation.
• public boolean supportsQueryParameterType(String className); - decides whether the query executers created by this factory support a query parameter type.

• Query parameters: embedded using the $P{..} syntax.
• Statement substitution parameters: embedded using the $P!{..} syntax.

• net.sf.jasperreports.hql.query.run.type - configures how the query result is fetched. It can take the following possible values: list, scroll, iterate.
• net.sf.jasperreports.jdbc.fetch.size - specifies the fetch size.
• net.sf.jasperreports.hql.clear.cache - flag used to clear the Hibernate’s first-level cache after each page fetching when working with a large amount of data.
• net.sf.jasperreports.hql.query.list.page.size - enables paginated result retrieval and specifies the page size.
• net.sf.jasperreports.hql.field.mapping.descriptions - instructs the engine to use rather field descriptions than names when mapping report fields to values from the Hibernate result.

<hibernate-configuration>

  <session-factory>
    <property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
    <property name="connection.url">jdbc:hsqldb:hsql://localhost</property>
    <property name="connection.username">sa</property>
    <property name="connection.password"></property>
    <property name="dialect">org.hibernate.dialect.HSQLDialect</property>
    <property name="connection.pool_size">1</property>
    <mapping resource="Address.hbm.xml"/>
    <mapping resource="Document.hbm.xml"/>
  </session-factory>

</hibernate-configuration>

  <hibernate-mapping>

  <class name="Address" table="ADDRESS">
    <id name="id" column="ID">
      <generator class="increment"/>
    </id>

    <property name="firstName" column="FIRSTNAME"/>
    <property name="lastName" column="LASTNAME"/>
    <property name="street" column="STREET"/>
    <property name="city" column="CITY"/>

    <set name="documents" inverse="true">
      <key column="ADDRESSID"/>
      <one-to-many class="Document"/>
    </set>
  </class>

  </hibernate-mapping>

  <hibernate-mapping>
	
    <class name="Document" table="DOCUMENT">
      <id name="id" column="ID">
        <generator class="increment"/>
      </id>

      <many-to-one name="address" column="ADDRESSID"/>

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

  <parameter name="CityFilter" class="java.util.List"/>
  <queryString language="hql">
    <![CDATA[select address as address, document.id as documentId, document.total as documentTotal
      from Address as address join address.documents as document
      where city not in ($P{CityFilter})
      order by address.city, address.lastName, address.firstName, address.id]] >
  </queryString>

  <queryString language="hql">
    <![CDATA[from Address address where city not in ($P{CityFilter}) order by $P!{OrderClause}]] >
  </queryString>

  <subreport>
    <reportElement x="65" y="21" width="50" height="20" isRemoveLineWhenBlank="true"/>
    <dataSourceExpression><![CDATA[new JRBeanCollectionDataSource($F{documents})]] ></dataSourceExpression>
    <subreportExpression class="java.lang.String"><![CDATA["DocumentsReport.jasper"]] ></subreportExpression>
  </subreport>

  private static Map getParameters(Session session)
  {
    Map parameters = new HashMap();
    parameters.put(JRHibernateQueryExecuterFactory.PARAMETER_HIBERNATE_SESSION, session);
    parameters.put("ReportTitle", "Address Report");
    List cityFilter = new ArrayList(3);
    cityFilter.add("Boston");
    cityFilter.add("Chicago");
    cityFilter.add("Oslo");
    parameters.put("CityFilter", cityFilter);
    parameters.put("OrderClause", "city");
    return parameters;
  }

  public void fill() throws JRException
  {
    Session session = createSession();
    Transaction transaction = session.beginTransaction();

    Map params = getParameters(session);
	
    File[] files = 
      new File[]{
        new File("build/reports/AddressesReport.jasper"),
        new File("build/reports/HibernateQueryReport.jasper")
        };
    for(int i = 0; i < files.length; i++)
    {
      File reportFile = files[i];
      long start = System.currentTimeMillis();
      JasperFillManager.fillReportToFile(reportFile.getAbsolutePath(), params);
      System.err.println(
        "Report : " + reportFile + ". Filling time : " + (System.currentTimeMillis() - start)
        );
    }
	
    transaction.rollback();
    session.close();
  }
  
  private static Session createSession()
  {
    SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
	
    return sessionFactory.openSession();
  }