applicationContext.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    <context:load-time-weaver />
    <tx:annotation-driven mode="aspectj" transaction-manager="transactionManager" />
    <context:annotation-config />
    <context:component-scan base-package="XXX" />
   
    <bean id="dataSource" class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init" destroy-method="close">
        <property name="uniqueResourceName"><value>DATABASE_XADBMS</value></property>
        <property name="xaDataSourceClassName" value="oracle.jdbc.xa.client.OracleXADataSource"/>       
        <property name="xaProperties">
            <props>
                <prop key="user">${db.username}</prop>
                <prop key="password">${db.password}</prop>
                <prop key="URL">${db.url}</prop>           
            </props>
        </property>
        <property name="poolSize" value="15" />
        <property name="maxPoolSize" value="30" />
        <property name="maxIdleTime" value="15" />
    </bean>


    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">

        <property name="annotatedClasses">
            <list>
                <value>XXX.XXX</value>               
            </list>
        </property>

        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration
            </value>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">
                    org.hibernate.dialect.Oracle9iDialect
                        </prop>
                <prop key="hibernate.query.substitutions">
                    true=1 false=0
                        </prop>

                <prop key="hibernate.show_sql">false</prop>
                <prop key="hibernate.format_sql">false</prop>
                <prop key="hibernate.use_sql_comments">false</prop>
                <prop key="hibernate.hbm2ddl.auto">validate</prop>
               
                <!-- http://www.atomikos.com/Documentation/JtaProperties  -->               
                <prop key="hibernate.current_session_context_class">jta</prop>                 
                <prop key="hibernate.transaction.manager_lookup_class">com.atomikos.icatch.jta.hibernate3.TransactionManagerLookup</prop>
                <prop key="javax.persistence.transactionType">jta</prop>

                <prop key="hibernate.transaction.auto_close_session">true</prop>
                <prop key="hibernate.connection.release_mode">auto</prop>
                <prop key="hibernate.transaction.flush_before_completion">true"</prop>
                <prop key="hibernate.cache.use_query_cache">false</prop>
                <prop key="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</prop>
            </props>
        </property>
        <property name="dataSource">
            <ref bean="dataSource" />
        </property>
    </bean>