Marco Piraccini [http://community.jboss.org/people/mpiraccini] created the discussion "Persistence and Transaction Management" To view the discussion, visit: http://community.jboss.org/message/613033#613033 -------------------------------------------------------------- Hi Guys, I have a very strange behaviour with JBPM5.1 and the persistence. I do not specify the TransactionManager in the Environment, but i set only the EntityManager. That seems to be correct, looking at the documentation (see 7.1.3 - Configuring Persistence). My persistence unit is configured in that way: <persistence-unit name="org.jbpm.persistence.jpa" transaction-type="RESOURCE_LOCAL">    <class>org.drools.persistence.info.SessionInfo</class>    <class>org.jbpm.persistence.processinstance.ProcessInstanceInfo</class>    <class>org.drools.persistence.info.WorkItemInfo</class>    <properties>           <property name="hibernate.hbm2ddl.auto" value="create-drop" />           <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver" />           <property name="hibernate.connection.username" value="xx" />           <property name="hibernate.connection.password" value="xx" />           <property name="hibernate.show_sql" value="true" />           <property name="hibernate.connection.url" value="jdbc:hsqldb:mem:test" />                                      <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>           <property name="hibernate.max_fetch_depth" value="3"/>           <property name="hibernate.show_sql" value="true"/>    </properties> </persistence-unit> The strange behaviour is that, when I try to run the code from a junit test using: Environment env = KnowledgeBaseFactory.newEnvironment(); env.set( EnvironmentName.ENTITY_MANAGER_FACTORY, emf ); JPAKnowledgeService.newStatefulKnowledgeSession(knowledgeBase, getKnowledgeSessionConfiguration(),env); I get this NPE: 18:39:06,775 ERROR [persistence.SingleSessionCommandService] Could not commit session java.lang.NullPointerException     at org.drools.persistence.jta.JtaTransactionManager.getStatus(JtaTransactionManager.java:197)     at org.drools.persistence.jta.JtaTransactionManager.begin(JtaTransactionManager.java:150)     at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:120)     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:122) There are some quite strange issues about that: 1) Why it uses the JtaTransactionManager even if the transaction-type is "RESOURCE_LOCAL"? 2) If I take a look at the JtaTransactionManager code, the NPE occurs because the UserTransaction is null. That's true, since no-one creates it! Indeed, looking at the SingleSessionCommandService method, the JtaTransactionManager is created in that way: this.txm = new JtaTransactionManager( env.get( EnvironmentName.TRANSACTION ),                                                       env.get( EnvironmentName.TRANSACTION_SYNCHRONIZATION_REGISTRY ),                                                       tm ); ...so, I have to specify the EnvironmentName.TRANSACTION to avoid the NPE? If so, why? Thank you, Marco. -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/613033#613033] Start a new discussion in jBPM at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]