jbpm hibernate persistence

[joshjdevl]

Hi,

We are using Hibernate as our persistence implementatio and Bitronix. I would like to configure JBPM peristence to use a hibernate entity manager so it can participate in our application transactions and go to our existing databases.

I've done something like this where I inject our jtaTransactionManager.

{code}
// create the entity manager factory and register it in the environment
        final EntityManagerFactory emf = new EntityManagerFactoryImpl(
                getSessionFactory(), PersistenceUnitTransactionType.JTA, true, null);
        final Environment env = KnowledgeBaseFactory.newEnvironment();
        env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf);
        // env.set(EnvironmentName.PERSISTENCE_CONTEXT_MANAGER, emf);
        env.set(EnvironmentName.TRANSACTION_MANAGER, jtaTransactionManager);
        // create a new knowledge session that uses JPA to store the runtime
        // state
        final StatefulKnowledgeSession ksession =
                JPAKnowledgeService.newStatefulKnowledgeSession(getKnowledgeBase(), null, env);
{code}

However, I receive the following error. Any clues/hints?

{code}
Caused by: java.lang.reflect.InvocationTargetException
          at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
          at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
          at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:116)
          ... 34 more
Caused by: java.lang.RuntimeException: Could not commit session
          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:136)
          ... 39 more
Caused by: java.lang.NullPointerException
          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:125)
          ... 39 more
{code}

[urdo2]

http://community.jboss.org/thread/161615

[afisboy]

Best I can tell, the above link doesn't point to a solution?!?

I see the same problem when attempting to use JPAKnowledgeService.newStatefulKnowledgeSession()

11:35:06,175 ERROR [STDERR] java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException

11:35:06,175 ERROR [STDERR]     at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:130)

11:35:06,175 ERROR [STDERR]     at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:54)

11:35:06,175 ERROR [STDERR]     at org.drools.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:109)

Source code in drools-persistence-jpa/src/main/java/org/drools/persistence/jpa/KnowledgeStoreServiceImpl.java

    private CommandExecutor buildCommanService(KnowledgeBase kbase,

                                              KnowledgeSessionConfiguration conf,

                                              Environment env) {

        Class< ? extends CommandExecutor> serviceClass = getCommandServiceClass();

        try {

            Constructor< ? extends CommandExecutor> constructor = serviceClass.getConstructor( KnowledgeBase.class,

                                                                                              KnowledgeSessionConfiguration.class,

                                                                                              Environment.class );

            return constructor.newInstance( kbase,

                                            conf,

                                            env );

        } catch ( SecurityException e ) {

            throw new IllegalStateException( e );

        } catch ( NoSuchMethodException e ) {

            throw new IllegalStateException( e );

        } catch ( IllegalArgumentException e ) {

            throw new IllegalStateException( e );

        } catch ( InstantiationException e ) {

            throw new IllegalStateException( e );

        } catch ( IllegalAccessException e ) {

            throw new IllegalStateException( e );

        } catch ( InvocationTargetException e ) {

            throw new IllegalStateException( e );

        }

    }

I assume JPAKnowledgeService.newStatefulKnowledgeSession() works for some people?  Anyone have some hints on what I'm doing wrong?

[afisboy]

Here is what worked for me.  Messing around with the source code, I found the exception was generated by the lack of a UserTransaction being included in the "env" object passed to JPAKnowledgeService.newStatefulKnowledgeSession().  Once I did that, all appears to be working.

[joshjdevl]

Do you have an example to share? Also, we use Hibernate so I create an entity manager factory and inject the session factory.

I tried

{code}
        final EntityManagerFactory emf = new EntityManagerFactoryImpl(
                getSessionFactory(), PersistenceUnitTransactionType.JTA, true, null);
        final Environment env = KnowledgeBaseFactory.newEnvironment();
        env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf);
        env.set(EnvironmentName.TRANSACTION_MANAGER, jtaTransactionManager);
        env.set(EnvironmentName.TRANSACTION, jtaTransactionManager.getUserTransaction());
{code}

Though receive

{code}
Caused by: java.lang.reflect.InvocationTargetException
          at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
          at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
          at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:116)
          ... 34 more
Caused by: java.lang.RuntimeException: Could not commit session
          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:136)
          ... 39 more
Caused by: java.lang.NullPointerException
          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:125)
          ... 39 more
{code}

[joshjdevl]

Looking at the code, it seems its not implemented. Thus this.jpm will be null

{code}
                   if (tm.getClass().getName().toLowerCase().contains("jpa")) {
                        // configure spring for JPA and local transactions
                        cls = Class.forName("org.drools.container.spring.beans.persistence.DroolsSpringJpaManager");
                        con = cls.getConstructors()[0];
                        this.jpm = (PersistenceContextManager) con.newInstance(new Object[] { this.env });
                    } else {
                        // configure spring for JPA and distributed transactions
                    }
{code}

[bpmn2user]

I have a simple persistence example (http://community.jboss.org/people/bpmn2user/blog/2011/03/25/jbpm5--persistence-hello-process-example) to that would not thow the exception 'Could not commit session' if the task server is run separately.

TomG: I am wondering what is the 'UserTransaction' configuration that is required in the 'env' object?

[afisboy]

I did a JNDI lookup on the UserTransaction and TransactionManager (I'm working with JBoss).  I added it to the env property

env.set(EnvironmentName.TRANSACTION_MANAGER, tm);

env.set(EnvironmentName.TRANSACTION, ut);

That got things to kind of work the JPAKnowledgeSesion, but it hasn't been stable.  I haven't had much luck getting the JPA versions to work.  I've been trying to get service tasks to work which would get up triggering threads to call the completeWorkItem calls on long running tasks.  Sometimes it works, sometimes it doesn't.  Its been discouraging trying to work within the JBoss container.  I suspect I'm not doing it right.  Has anyone had any luck running within JBoss using JPA versions?

[bpmn2user]

I did notice transaction problem with the example (http://community.jboss.org/people/bpmn2user/blog/2011/03/25/jbpm5--persistence-hello-process-example) if I use both the persistence units (process and task) together.

I have not tried the example with JBoss, but I presume it is something to do with the UserTransaction configuration as you had mentioned. As the JBPM5 console works on JBoss server (also JBPM console works fine with Tomcat/Oracle http://community.jboss.org/people/bpmn2user/blog/2011/02/26/orcale-integration-with-jbpm5), I think it has to do the UserTrasaction/JTA configuration.

[bpmn2user]

I did notice transaction problem with the example (http://community.jboss.org/people/bpmn2user/blog/2011/03/25/jbpm5--persistence-hello-process-example) and Oracle database if I use both the persistence units (process and task) together.

I have not tried the example with JBoss, but I presume it is something to do with the UserTransaction configuration as you had mentioned. As the JBPM5 console works on JBoss server (also JBPM console works fine with Tomcat/Oracle http://community.jboss.org/people/bpmn2user/blog/2011/02/26/orcale-integration-with-jbpm5), I think it has to do the UserTrasaction/JTA configuration.

[afisboy]

I found out what I was doing wrong.  I am able to get the transaction manager and user transactions to work fine in JBoss.  My screw up was with "Service Tasks".  I was getting process instance ids mixed up with work item ids.  I learned there are 2 ids involved when correctly identifying a workitem to complete when the completion is outside of the listener's callback (a long running task).  The session id, and the work item id.

[supritchaudhary]

Check that you have correct version of jbpm-persistence-jpa* in your classpath.

If you have "jbpm-persistence-jpa-5.2.0.Final.jar" and other jbpm files of version 5.3.0.Final you are likely to have this problem.

[girish.bapat]

This helped me thanks for pointing out