What I want:
I'm creating a prototype that is supposed to read a bpmn2 file and list all its tasks.
What I'm using:
Currently I have a simple Maven application using jBPM 6. I don't need any application server, workbench etc., because it's just a simple desktop application.
The issue:
If I initialize the engine like this (as suggested by the official documentation):
RuntimeEnvironment environment =
RuntimeEnvironmentBuilder.Factory.get()
.newDefaultInMemoryBuilder()
.persistence(false)
.addAsset(ResourceFactory.newClassPathResource("poc4.bpmn2"), ResourceType.BPMN2)
.get();
I get this error:
Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named org.jbpm.persistence.jpa
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:69)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)
at org.jbpm.runtime.manager.impl.DefaultRuntimeEnvironment.init(DefaultRuntimeEnvironment.java:72)
at org.jbpm.runtime.manager.impl.RuntimeEnvironmentBuilder.get(RuntimeEnvironmentBuilder.java:314)
at org.jbpm.runtime.manager.impl.RuntimeEnvironmentBuilder.get(RuntimeEnvironmentBuilder.java:56)
at com.test.jbpmpoc.main(App.java:11)
Note that I'm trying to start the engine with the persistence explicitly disabled, but I believe that's not needed because the documentation says that the engine does NOT use persistence by default.
What I know:
Accordingly to my researches, there are at least two ways of initializing the engine.
Using a builder that provides the runtime environment - which I'm already doing. This seems the most recommended way of doing it, because all services would be initialized by default. However, as said here and here, this method requires a persistence to be set up if you want to use Tasks (which is something that I do);
Initialize everything manually. I don't like much this one because it sounds too much effort to have a simple application running.
Using other runtime environment builders.
What I have tried:
At first, I tried to use the persistence.xml suggested by the documentation, but I get a different error when I create the EntityManagerFactory:
Exception in thread "main" javax.persistence.PersistenceException: Unable to build entity manager factory
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:83)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)
at com.test.jbpmpoc.App.main(App.java:30)
Caused by: org.hibernate.engine.jndi.JndiException: Error parsing JNDI name [jdbc/jbpm-ds]
at org.hibernate.engine.jndi.internal.JndiServiceImpl.parseName(JndiServiceImpl.java:141)
at org.hibernate.engine.jndi.internal.JndiServiceImpl.locate(JndiServiceImpl.java:112)
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.configure(DatasourceConnectionProviderImpl.java:115)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:260)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:94)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1887)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1845)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:857)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:425)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:849)
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:75)
... 3 more
Caused by: javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
at javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(Unknown Source)
at javax.naming.InitialContext.getNameParser(Unknown Source)
at org.hibernate.engine.jndi.internal.JndiServiceImpl.parseName(JndiServiceImpl.java:135)
... 20 more
I'm not using an application server and don't have the JTA Datasource and ORM files, so I commented the lines that point to these files in order to fix this JNDI error, then I get this other exception:
Exception in thread "main" java.lang.NoSuchMethodError: javax.persistence.NamedQuery.lockMode()Ljavax/persistence/LockModeType;
at org.hibernate.cfg.annotations.QueryHintDefinition.determineLockOptions(QueryHintDefinition.java:138)
at org.hibernate.cfg.annotations.QueryBinder.bindQuery(QueryBinder.java:72)
at org.hibernate.cfg.annotations.QueryBinder.bindQueries(QueryBinder.java:219)
at org.hibernate.cfg.AnnotationBinder.bindQueries(AnnotationBinder.java:374)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:618)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processAnnotatedClassesQueue(Configuration.java:3845)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3799)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1412)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:857)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:425)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:849)
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:75)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)
at com.test.jbpmpoc.App.main(App.java:30)
I'm pretty sure I'm getting closer here. Do I really need the JTA datasource and ORM files if I'm running outside an application server? The jBPM installer doesn't come with these, where can I find them?
I also tried to use an empty builder instead of one of the default builders, so I would need to initialize everything manually, including the TaskService, which I believe I need to start if I want to manage the tasks (list, execute, etc). However, it requires the persistence.xml too, because I keep getting the No Persistence provider message.
Edit
I should have guessed earlier that the NoSuchMethodError exception was being caused by a Maven artifact in the wrong version. I also had JTA as my transaction strategy in my persistence definition but wasn't providing any jta datasource. However, now that I've changed my pom.xml and persistence.xml, I'm getting this error:
Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: org.jbpm.persistence.jpa] Unable to build EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:900)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:57)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)
at com.test.jbpmpoc.App.main(App.java:30)
Caused by: org.hibernate.HibernateException: Errors in named queries: GetProcessInstanceIdByCorrelation
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:435)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1385)
at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:954)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:891)
... 4 more
It seems that one of the named queries form the JBPMorm.xml file is wrong. I copied this file from JBPM source code.
More info about my Java project:
All the examples and tutorials I've found are focused on creating web apps running on application servers, but in my case the absence of an application server requires a workaround that I'm still yet to find. Has anyone managed to run a simple desktop application using jBPM 6?
