hi all!

I am using hibernate and spring and all my DAOs extend HibernateDAOSupport.
I have an entity 'Order' which contains an attribute 'Quote' and Quote contains collections of 'Buy' and 'Sell' values.

<class name="Order" table="ORDERS" lazy="false">
<id name="objectId" column="ORDER_UUID">
<generator class="uuid.hex"/>
</id>
<!-- for Quote -->
<many-to-one name="Quote" class="Quote"
column="quote_id"
cascade="all"
unique="true"/>

</class>

<class name="Quote" table="QUOTE">
<id name="id" column="QUOTE_ID">
<generator class="sequence">
<param name="sequence">quote_sequence</param>
</generator>
</id>
<map name="sell" table="sell" sort="natural">
<key column="quote_id"/>
<index column="price"/>
---------
</map>
<map name="buy" table="buy" sort="natural">
<key column="quote_id"/>
<index column="price"/>
---------
</map>
</class>

As you must have noticed, I am using lazy="false" and cascade="all" in Order mapping. So my Order object has all its collection initialized.

Now problem is when I stress test my code to store and update an order it throws the following error:
Illegal attempt to associate a collection with two open sessions

I Suppose reason is, the collections are not versioned like objects so when the same collection is opened with multiple sessions HB doesn't know who's going to win, as mentioned by Costin Leau in the following thread,
http://forum.springsource.org/showthread.php?t=26782

Can any one please suggest me solution to it?
Any help is appreciated.

Thanks

Synchronize access to the method that's doing save or update.

Thanks Jim.
I think that will work.

you're most welcome.

Hi,
Problem is not solved completely as i thought it to be.
I have synchrinozed my DAO method which calls getHibernateTemplate().saveOrUpdate(order) which solved the two session problem.
But I am getting java.util.ConcurrentModificationException as follows:

15:29:34.831 [AnonymousIoService-10] ERROR errors Exception caught!
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.invoke(DispatchListener.java:175) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.processMessage(DispatchListener.java:111) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
at com.miriamlaurel.blackjack.server.SessionManager.messageReceived(SessionManager.java:385) [classes/:na]
at com.miriamlaurel.blackjack.server.SessionManager.messageReceived(SessionManager.java:1) [classes/:na]
at org.apache.mina.handler.demux.DemuxingIoHandler.messageReceived(DemuxingIoHandler.java:141) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain$TailFilter.messageReceived(AbstractIoFilterChain.java:570) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648) [mina-core-1.1.7.jar:na]
at org.apache.mina.filter.codec.support.SimpleProtocolDecoderOutput.flush(SimpleProtocolDecoderOutput.java:58) [mina-core-1.1.7.jar:na]
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:180) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53) [mina-core-1.1.7.jar:na]
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648) [mina-core-1.1.7.jar:na]
at org.apache.mina.filter.executor.ExecutorFilter.processEvent(ExecutorFilter.java:220) [mina-core-1.1.7.jar:na]
at org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(ExecutorFilter.java:264) [mina-core-1.1.7.jar:na]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_13]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_13]
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51) [mina-core-1.1.7.jar:na]
at java.lang.Thread.run(Thread.java:619) [na:1.6.0_13]
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [na:1.6.0_13]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [na:1.6.0_13]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_13]
at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_13]
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.invoke(DispatchListener.java:171) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
... 19 common frames omitted
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.invoke(DispatchListener.java:175) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.processMessage(DispatchListener.java:111) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
at com.miriamlaurel.blackjack.server.SessionManager.onMessage(SessionManager.java:177) [classes/:na]
... 24 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [na:1.6.0_13]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [na:1.6.0_13]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_13]
at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_13]
at com.miriamlaurel.pms.listeners.dispatch.DispatchListener.invoke(DispatchListener.java:171) [miriamlaurel-pms-1.0-SNAPSHOT.jar:na]
... 26 common frames omitted
Caused by: java.util.ConcurrentModificationException
at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1100) [na:1.6.0_13]
at java.util.TreeMap$EntryIterator.next(TreeMap.java:1136) [na:1.6.0_13]
at java.util.TreeMap$EntryIterator.next(TreeMap.java:1131) [na:1.6.0_13]
at org.hibernate.persister.collection.BasicCollectionPersister.doUpdateRows(BasicCollectionPersister.java:206) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.persister.collection.AbstractCollectionPersister.updateRows(AbstractCollectionPersister.java:1541) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.action.CollectionUpdateAction.execute(CollectionUpdateAction.java:85) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:170) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) [hibernate-3.3.1.GA.jar:na]
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) [hibernate-3.3.1.GA.jar:na]
at org.springframework.orm.hibernate3.HibernateAccessor.flushIfNecessary(HibernateAccessor.java:390) [spring-2.5.4.jar:2.5.4]
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:420) [spring-2.5.4.jar:2.5.4]
at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374) [spring-2.5.4.jar:2.5.4]
at org.springframework.orm.hibernate3.HibernateTemplate.saveOrUpdate(HibernateTemplate.java:744) [spring-2.5.4.jar:2.5.4]
at com.tsdevelopment.blackjack.server.dao.impl.hibernate.OrderDaoImpl.storeOrder(OrderDaoImpl.java:32) [classes/:na]
at com.miriamlaurel.blackjack.server.services.DataManager.storeOrder(DataManager.java:55) [classes/:na]
at com.miriamlaurel.blackjack.server.services.SignalOrderProcessor.changeOrderState(SignalOrderProcessor.java:315) [classes/:na]
at com.miriamlaurel.blackjack.server.services.SignalOrderProcessor.executeOrder(SignalOrderProcessor.java:97) [classes/:na]
at com.miriamlaurel.blackjack.server.services.SignalOrderProcessor.putOrder(SignalOrderProcessor.java:87) [classes/:na]
at com.miriamlaurel.blackjack.server.services.SignalOrderProcessor.process(SignalOrderProcessor.java:393) [classes/:na]
at com.miriamlaurel.blackjack.server.dispatch.AccountDispatcher.onSignal(AccountDispatcher.java:134) [classes/:na]
... 31 common frames omitted

Now since I have synchronized the saveOrUpdate method I am unable to understand thsi exception.
I feel probably this is not the best way to handle collection in hibernate.
Can any one please guide me with the correct approach to solve thsi problem.

Any help appreciated!

Thanks again...

This exception has got nothing to do with synchronization. And probably nothing to do with Hibernate as well. It looks like that you are changing some collection as you are iterating over it. Please atleast try to debug the problem before jumping to conclusions.

thanks for your reply.
I agree its a java collecion error which has nothing to do with hibernate.
The exception is actually being thrown from OrderDaoImpl.storeOrder in code that has to do with collections in quote.price.
Following is my code for OrderDaoImpl.storeOrder:



SO point is I dont handle any of these collections myself. They are handled(save or updated) by hibernate on call of saveOrUpdate of order.
Also i want to confirm if this is how every one handles collections in case of cascade

I also still new to hibernate, but, I think your problem is in opening a session twice, as i encountered this problem before.

You should grantee that there is a single session you use in your operations.

for example, you may use HibernateUtil.getSessionFactory().getCurrentSession(); to obtain a new session and you make sure that you don't close it until you do with all your operations needed for this session.

I hope you get it, thanks.