Hibernate exception - Illegal attempt to associate a collection with two open session

[damogallagher]

Hello

I have the following error trace when i try to perform an update.
All my beans are being read in from an xml file and updates work perfectly for other dao methods.

org.springframework.orm.hibernate.HibernateSystemE xception: Illegal attempt to associate a collection with two open sessions; nested exception is net.sf.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
net.sf.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
at net.sf.hibernate.collection.PersistentCollection.s etCurrentSession(PersistentCollection.java:257)
at net.sf.hibernate.impl.OnUpdateVisitor.processColle ction(OnUpdateVisitor.java:38)
at net.sf.hibernate.impl.AbstractVisitor.processValue (AbstractVisitor.java:69)
at net.sf.hibernate.impl.AbstractVisitor.processValue s(AbstractVisitor.java:36)
at net.sf.hibernate.impl.AbstractVisitor.process(Abst ractVisitor.java:91)
at net.sf.hibernate.impl.SessionImpl.doUpdateMutable( SessionImpl.java:1465)
at net.sf.hibernate.impl.SessionImpl.doUpdate(Session Impl.java:1479)
at net.sf.hibernate.impl.SessionImpl.update(SessionIm pl.java:1364)
at org.springframework.orm.hibernate.HibernateTemplat e$11.doInHibernate(HibernateTemplate.java:530)
at org.springframework.orm.hibernate.HibernateTemplat e.execute(HibernateTemplate.java:317)
at org.springframework.orm.hibernate.HibernateTemplat e.update(HibernateTemplate.java:527)
at org.springframework.orm.hibernate.HibernateTemplat e.update(HibernateTemplate.java:523)
at com.fmr.eca.dao.hibernate.ExpenseTypeDaoHibernate. modifyExpenseType(ExpenseTypeDaoHibernate.java:141 )
at junit.com.fmr.eca.dao.hibernate.TestExpenseTypeDao Hibernate.testModifyExpenseTypes(TestExpenseTypeDa oHibernate.java:145)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:41)
at java.lang.reflect.Method.invoke(Method.java:386)
at junit.framework.TestCase.runTest(TestCase.java:154 )
at junit.framework.TestCase.runBare(TestCase.java:127 )
at junit.framework.TestResult$1.protect(TestResult.ja va:106)
at junit.framework.TestResult.runProtected(TestResult .java:124)
at junit.framework.TestResult.run(TestResult.java:109 )
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:2 08)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.runTests(RemoteTestRunner.java:392)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.run(RemoteTestRunner.java:276)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.main(RemoteTestRunner.java:167)




Why would this error be happening?
Any help greatly appreciated

Regards
Damien

[katentim]

Why would this error be happening?

You must be using a collection associated with one session in another session. Would have to look at the code to determine where.

You find a better explanation here: http://forum.hibernate.org/

[Costin Leau]

Btw, try searching the forum - you should find plenty of posts on this topic.

[welkinhu]

I have searched forum for this problem. However, this topic is the only hit.

It is too strange. When I run
IdentityService service = new IdentityServiceImpl();
service.update();
Everything is okay.

When I run
IdentityService service = Context.getBean(...);
service.update();

This exception will be throwed.

In update(), I call dao loading a pojo and updating it.

It obviously due to SessionFactoryUtils returns two sessions: loading is a session, updationg is another session. Why?

[Andrei Stefan]

Can you post more details ? (actual test code, config file etc)

[karldmoore]

As Andrei said posting more details would help. One point however is that if you are creating your service using the new operator, it's not going to be Spring managed and hence you are going to have completely different behaviour/problems.

[welkinhu]

===Illegal attempt to associate a collection with two open session===
====Exception Message====
org.springframework.orm.hibernate3.HibernateSystem Exception: Illegal attempt to associate a collection with two open sessions;

nested exception is org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions

====Cause====
The program started two or more transactions while we expected only one. It is a fact caused by incorrect transaction AOP configuration in Spring context.xml

Our default transaction AOP config is:
<tx:advice id="txAdvice">
<tx:attributes>
<tx:method name="add*" propagation="REQUIRED"/>
<tx:method name="delete*" propagation="REQUIRED"/>
<tx:method name="update*" propagation="REQUIRED"/>
<tx:method name="move*" propagation="REQUIRED"/>
<tx:method name="save*" propagation="REQUIRED" />
<tx:method name="*" propagation="SUPPORTS" read-only="true" />
</tx:attributes>
</tx:advice>

This configuration means: all methods start with "add", "delete", "update", "move", "save" require transaction. all other methods support transaction.

for example, method login() calls load() and update(). both login() and load() do not require transaction, but support it. update() require transaction.

However, Both load() and update() will start new transaction. But we expected load() is out of transaction of at the same transaction with update().

====Fixing====
Declare the new method as REQUIRED.
# declare load*, find* and all other persistence query method as REQUIRED.
# declare All APIs as REQUIRED, as long as it called persistence CUD methods.

[Andrei Stefan]

PROPAGATION_SUPPORTS doesn't start a transaction, only REQUIRED and REQUIRES_NEW do that.
A Hibernate session doesn't necessarily mean that you'll have a transaction.
Juergen's post from this thread explains better the behavior of PROPAGATION_SUPPORTS.

[karldmoore]

I'm not sure I understand the solution either. I'd be quite interested to see the code and configuration that worked and didn't (in [code] [ /code] tags) just to understand what was going on.