Question

I’m creating my first JPA application using NetBeans. I’m unable to make the persistence work. The connection to database works well, when I run the application the database tables got created. But when I try to create EntityManagerFactory:

EntityManagerFactory emf = Persistence.createEntityManagerFactory("PISProjektPU");

I get:

INFO: javax.persistence.PersistenceException: [PersistenceUnit: PISProjektPU] Unable to build EntityManagerFactory
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:677)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:126)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:78)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
    at cz.vutbr.fit.pis.spravaTechniky.service.TestManager.<init>(TestManager.java:28)
    at cz.vutbr.fit.pis.spravaTechniky.service.__EJB31_Generated__TestManager__Intf____Bean__.<init>(Unknown Source)
...

My persistence.xml file looks like this (generated by NetBeans, I didn’t change anything):

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="PISProjektPU" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>jdbc/myslq_spravaTechniky</jta-data-source>
    <class>cz.vutbr.fit.pis.spravaTechniky.data.TestEntity</class>
    <exclude-unlisted-classes>true</exclude-unlisted-classes>
    <properties>
    </properties>
</persistence-unit>
</persistence>

and it’s located here:

src/conf/persistence.xml
build/web/WEB-INF/classes/META-INF/persistence.xml

I searched the forum and found some tips how to remove this error, but I was unable to make it work. I tried to add these two lines to Manifest.mf:

Meta-Persistence: META-INF/persistence.xml
JPA-PersistenceUnits: PISProjektPU

I tried to move the persistence.xml file to all possible locations. I also added all libraries that seemed like they might be useful, when I go to Properties/Libraries, I see:

Java EE 6 API Library
Hibernate
Java-EE-GlassFish-v3
EclipseLink(JPA 2.0)
EclipseLink-GlassFish-v3
Hibernate JPA
JSF 2.0
Java EE Web 6 API Library
Persistence

I’m sure I’m doing some stupid simple mistake, but after a day trying to make this work I am unable to see where is the problem. To be honest right now I’m just totally confused about where to put which file or how to configure everything, so I’m randomly trying different things. I will be thankful for any advice!

Edit:

Thanks for the suggestion. My test classes actually look like this:

Class TestManager:

@Stateless
public class TestManager {
    @PersistenceContext 
    private EntityManager em;

    public void save(TestEntity t) {
        em.merge(t);
    }

    public void remove(TestEntity t) {
        em.remove(em.merge(t));
    }

    public void create(TestEntity t) {
        em.persist(t);
    }

    @SuppressWarnings("unchecked")
        public List<TestEntity> findAll() {
        return em.createQuery("SELECT t FROM TestEntity t").getResultList();
    }
}

Class TestBean:

@Named(value="testBean")
@Dependent
public class TestBean {

    @EJB
    private TestManager testManager;

    /** Creates a new instance of TestBean */
    public TestBean() {
    }

    public List<TestEntity> getEntities() {
        return this.testManager.findAll();
    }

}

I’m calling the TestBean.getEntities method:

...
<h:dataTable value="#{testBean.entities}" var="entity">
...

This causes the following exception:

javax.ejb.EJBException
at com.sun.ejb.containers.BaseContainer.processSystemException(BaseContainer.java:5119)
at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:5017)
at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4805)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2004)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1955)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:198)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:84)
at $Proxy141.findAll(Unknown Source)
at cz.vutbr.fit.pis.spravaTechniky.service.__EJB31_Generated__TestManager__Intf____Bean__.findAll(Unknown Source)
at cz.vutbr.fit.pis.spravaTechniky.back.TestBean.getEntities(TestBean.java:27)
...

I tried to replace the @PersistenceContext with @EJB, but got javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB.

Answer 1

In the end I made JPA work just by using one of the example projects in NetBeans (File > New Project > Samples > Java Web > JSF JPA). I used this as a base for my project. I am not sure what I was doing wrong but at least everything worked fine then. Anyway, thanks for the help!