Adding additional persistence units

[Merve Temizer]

 i am trying to add addititonal `persistence unit`. I do not think it is
specific to James, I searched net and ran into a post (independent from
James, only related to Spring and java) that says the error is about
creating two instances of a `Singleton` during multiple `EntityManager`
injection. I think it is not specific to James but i think maybe you have
some idea.

Adding multiple persistence units causes error:

    Caused by: java.lang.LinkageError: loader (instance of
 sun/misc/Launcher$AppClassLoader): attempted  duplicate class definition
for name: "org/springframework/stereotype/Service"

Lines from persistence.xml, when i delete one unit error is out.

    <persistence-unit name="James" transaction-type="RESOURCE_LOCAL">
                <!-- Mailbox stuff-->

<class>org.apache.james.mailbox.jpa.mail.model.JPAMailbox</class>

<class>org.apache.james.mailbox.jpa.mail.model.JPAUserFlag</class>

<class>org.apache.james.mailbox.jpa.mail.model.openjpa.AbstractJPAMessage</class>

<class>org.apache.james.mailbox.jpa.mail.model.openjpa.JPAMessage</class>

<class>org.apache.james.mailbox.jpa.mail.model.openjpa.JPAMessage</class>

<class>org.apache.james.mailbox.jpa.mail.model.JPAProperty</class>

<class>org.apache.james.mailbox.jpa.user.model.JPASubscription</class>

<class>org.apache.james.domainlist.jpa.model.JPADomain</class>
                <class>org.apache.james.user.jpa.model.JPAUser</class>

<class>org.apache.james.rrt.jpa.model.JPARecipientRewrite</class>
                <class>com.merve.DenemeEntity</class>

                <properties>
                    <property name="openjpa.jdbc.SynchronizeMappings"
value="buildSchema(ForeignKeys=true)"/>
                    <property name="openjpa.jdbc.MappingDefaults"
value="ForeignKeyDeleteAction=cascade, JoinForeignKeyDeleteAction=cascade"/>
                    <property name="openjpa.jdbc.SchemaFactory"
value="native(ForeignKeys=true)"/>
                    <property name="openjpa.jdbc.QuerySQLCache"
value="false"/>
                </properties>

            </persistence-unit>

        <persistence-unit name="PU" transaction-type="RESOURCE_LOCAL">

               <properties>
          <property name="hibernate.hbm2ddl.auto" value="create" />
          <property name="hibernate.show_sql" value="false" />

        <property name="hibernate.max_fetch_depth" value="0"  />
        <property name="hibernate.cache.use_second_level_cache"
value="true" />
        <property name="hibernate.cache.use_query_cache" value="false" />
        <property name="hibernate.cache.region.factory_class"
value="net.sf.ehcache.hibernate.EhCacheRegionFactory" />

          <property name="hibernate.ejb.naming_strategy" value="aclass"/>

        </properties>

            </persistence-unit>


Thanks for possible advices.