How to continue process in a web application

[johnesky]

//StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();

I want to continue the process in another JSP page but I don't know what method to call from the kbase object to  initialize with ksession to load the previous state from the database.

How can I load the current state of my process from the database to continue my process?

[calca]

Hi man, this should help:

StatefulKnowledgeSession session = JPAKnowledgeService.loadStatefulKnowledgeSession(sessionId, kbase, config, env)

Demian

[johnesky]

Thanks Demian. BUt how can I get the sessionId?

[calca]

You may save it in a variable before disposing the session, for example after creating the session:

ksession = JPAKnowledgeService.newStatefulKnowledgeSession(kbase, null, environment);

int sessionId = ksession.getId();

[johnesky]

Thanks Demian. I got this error using JPAKnowledgeService.newStatefulKnowledgeSession( kbase, null, env ). What do you think I am doing wrong to get Java null pointer exception:

Exception in thread "main" java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:130)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:54)

          at org.drools.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:109)

          at com.sample.ProcessTest.main(ProcessTest.java:69)

Caused by: java.lang.reflect.InvocationTargetException

          at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

          at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

          at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:116)

          ... 3 more

Caused by: java.lang.RuntimeException: Could not commit session or rollback

          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:133)

          ... 8 more

Caused by: java.lang.RuntimeException: Unable to rollback transaction

          at org.drools.persistence.jta.JtaTransactionManager.rollback(JtaTransactionManager.java:184)

          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:131)

          ... 8 more

Caused by: java.lang.NullPointerException

          at org.drools.persistence.jta.JtaTransactionManager.rollback(JtaTransactionManager.java:181)

          ... 9 more

Here is part of my code below:

KnowledgeBase kbase = readKnowledgeBase();

                      EntityManagerFactory emf =

                          Persistence.createEntityManagerFactory( "org.jbpm.task" );

                      Environment env = KnowledgeBaseFactory.newEnvironment();

                      env.set( EnvironmentName.ENTITY_MANAGER_FACTORY, emf );

                      StatefulKnowledgeSession ksession =  JPAKnowledgeService.newStatefulKnowledgeSession( kbase, null, env );

   ksession.startProcess("com.sample.bpmn.hello");

Thanks again for your time.

[calca]

Try with

EntityManagerFactory emf = Persistence

                                        .createEntityManagerFactory("org.jbpm.persistence.jpa");

"org.jbpm.task" should be used to construct your task service, not to create the session (for example, https://github.com/calcacuervo/JBPM5-Samples/blob/master/human-tasks/src/test/java/com/test/BaseHumanTaskTest.java)

Demian

[garytse]

>>>

Caused by: java.lang.RuntimeException: Unable to rollback transaction

          at org.drools.persistence.jta.JtaTransactionManager.rollback(JtaTransactionManager.java:184)

          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:131)

          ... 8 more

Caused by: java.lang.NullPointerException

          at org.drools.persistence.jta.JtaTransactionManager.rollback(JtaTransactionManager.java:181)

          ... 9 more

<<<

My guess, is that you're trying to run it outside a J2EE container; it doesnt work.  (see https://issues.jboss.org/browse/JBPM-3282) 

Otherwise, double check the persistence.xml file

[johnesky]

Gary thanks for replying, but the thread wasn't helpful.

Thanks a lot Demian, it was a perfect example for me. Through the example I was able to run the application as a desktop applicaton, and it worked perfectly fine and persisted to my postgres database. But when I decided to run the same application as a web application with tomcat 6.0 for deployment, then I get this error and do you know why:

SEVERE: Could not synchronize database state with session

org.hibernate.exception.GenericJDBCException: could not insert: [org.drools.persistence.info.SessionInfo]

          at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)

          at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)

          at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2295)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2688)

          at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79)

          at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)

          at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)

          at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:167)

          at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)

          at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)

          at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)

          at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)

          at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:504)

          at bitronix.tm.BitronixTransaction.fireBeforeCompletionEvent(BitronixTransaction.java:478)

          at bitronix.tm.BitronixTransaction.commit(BitronixTransaction.java:193)

          at bitronix.tm.BitronixTransactionManager.commit(BitronixTransactionManager.java:120)

          at org.drools.persistence.jta.JtaTransactionManager.commit(JtaTransactionManager.java:167)

          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:127)

          at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

          at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

          at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:116)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:54)

          at org.drools.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:109)

          at org.apache.jsp.index_jsp._jspService(index_jsp.java:174)

          at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

          at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

          at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)

          at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)

          at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)

          at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

          at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

          at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

          at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

          at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

          at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

          at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)

          at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)

          at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)

          at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

          at java.lang.Thread.run(Thread.java:619)

Caused by: org.postgresql.util.PSQLException: Large Objects may not be used in auto-commit mode.

          at org.postgresql.largeobject.LargeObjectManager.createLO(LargeObjectManager.java:241)

          at org.postgresql.largeobject.LargeObjectManager.createLO(LargeObjectManager.java:228)

          at org.postgresql.jdbc2.AbstractJdbc2Statement.setBlob(AbstractJdbc2Statement.java:2817)

          at org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.setBlob(DelegatingPreparedStatement.java:181)

          at org.hibernate.type.ByteArrayBlobType.set(ByteArrayBlobType.java:106)

          at org.hibernate.type.AbstractLobType.nullSafeSet(AbstractLobType.java:57)

          at org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:2025)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2271)

          ... 41 more

Jul 25, 2011 10:09:46 AM org.drools.persistence.jta.JtaTransactionManager commit

WARNING: Unable to commit transaction

javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not insert: [org.drools.persistence.info.SessionInfo]

          at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)

          at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:513)

          at bitronix.tm.BitronixTransaction.fireBeforeCompletionEvent(BitronixTransaction.java:478)

          at bitronix.tm.BitronixTransaction.commit(BitronixTransaction.java:193)

          at bitronix.tm.BitronixTransactionManager.commit(BitronixTransactionManager.java:120)

          at org.drools.persistence.jta.JtaTransactionManager.commit(JtaTransactionManager.java:167)

          at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:127)

          at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

          at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

          at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:116)

          at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:54)

          at org.drools.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:109)

          at org.apache.jsp.index_jsp._jspService(index_jsp.java:174)

          at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

          at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

          at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)

          at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)

          at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)

          at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

          at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

          at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

          at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

          at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

          at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

          at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)

          at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)

          at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)

          at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

          at java.lang.Thread.run(Thread.java:619)

Caused by: org.hibernate.exception.GenericJDBCException: could not insert: [org.drools.persistence.info.SessionInfo]

          at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)

          at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)

          at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2295)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2688)

          at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79)

          at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)

          at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)

          at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:167)

          at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)

          at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)

          at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)

          at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)

          at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:504)

          ... 31 more

Caused by: org.postgresql.util.PSQLException: Large Objects may not be used in auto-commit mode.

          at org.postgresql.largeobject.LargeObjectManager.createLO(LargeObjectManager.java:241)

          at org.postgresql.largeobject.LargeObjectManager.createLO(LargeObjectManager.java:228)

          at org.postgresql.jdbc2.AbstractJdbc2Statement.setBlob(AbstractJdbc2Statement.java:2817)

          at org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.setBlob(DelegatingPreparedStatement.java:181)

          at org.hibernate.type.ByteArrayBlobType.set(ByteArrayBlobType.java:106)

          at org.hibernate.type.AbstractLobType.nullSafeSet(AbstractLobType.java:57)

          at org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:2025)

          at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2271)

          ... 41 more

[calca]

It seems to be related with transaction configuration, in which the UserTransaction is not being created. I configured it following these:

http://community.jboss.org/people/bpmn2user/blog/2011/02/26/orcale-integration-with-jbpm5

And worked.

If is does not work, please attach some test that shows your persistence/transaction configuration.

Regards,

Demian

[calca]

Did you configure your tomcat with Bitronix, like the link http://community.jboss.org/people/bpmn2user/blog/2011/02/26/orcale-integration-with-jbpm5 ?

[johnesky]

yes I did.

[johnesky]

Hi Demian, I got it solved now. I had to set Hibernate autocomit to false. Thanks for your time, really appreciate it. I just can't get the process to continue in another JSP page which is frustrating. When I run the other jsp page to continue the process it clears all data in the task table. And also, the sessioninfo table isn't persisting. What do you think I may be doing wrong?

[mariemm]

Don't have you

<property name="hibernate.hbm2ddl.auto" value="create"/> in persistence.xml?

[johnesky]

Thanks Marie. But create is also doing the same. I had create-drop before.