EJB deployment in Apache TomEE using Hibernate Persistence Provider and MySQL DB

I'm facing a problem in configuration for a project what is build on EJB 3.0 technology. As the server container i'm using Apache TomEE v.7.0 with (with built in OpenEJB module), MySQL database and hibernate as the persistence provider.

Below is my configuration files:

tomee.xml

<?xml version="1.0" encoding="UTF-8"?>
<tomee>
<Resource id="lrsDataSource" type="javax.sql.DataSource">
    JdbcDriver com.mysql.jdbc.Driver
    JdbcUrl jdbc:mysql://localhost:3306/lbrentalservice
    UserName root
    Password 123456
    JtaManaged true
</Resource>
</tomee>

persistence.xml

<persistence xmlns="http://ift.tt/UICAJV"
             xmlns:xsi="http://ift.tt/ra1lAU"
             xsi:schemaLocation="http://ift.tt/UICAJV http://ift.tt/O9YdEP"
             version="2.0">
  <persistence-unit name="lrs-unit" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>lrsDataSource</jta-data-source>
    <non-jta-data-source>lrsDataSourceUnmanaged</non-jta-data-source>
    <class>edu.drg.entity.Book</class>
    <class>edu.drg.entity.Category</class>
    <class>edu.drg.entity.Person</class>
    <class>edu.drg.entity.RentActivity</class>
    <properties>
      <property name="hibernate.hbm2ddl.auto" value="create"/>
      <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
      <property name="hibernate.query.factory_class"
                value="org.hibernate.hql.internal.classic.ClassicQueryTranslatorFactory" />
      <property name="hibernate.transaction.manager_lookup_class"
                value="org.apache.openejb.hibernate.TransactionManagerLookup"/>
    </properties>
  </persistence-unit>
</persistence>

Person entity (other entities are similar)

@Entity
@Table (name="person", uniqueConstraints = { @UniqueConstraint(columnNames = "prs_id")})
@NamedQueries({
    @NamedQuery(name="findAllPersons", query = "SELECT p FROM Person p")
})
public class Person implements IPerson, Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private Long personId;
    private String personName;
    private String personSurname;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="prs_id")
    public Long getPersonId() {
        return personId;
    }
    public void setPersonId(Long personId) {
        this.personId = personId;
    }
    @Column(name="name")
    public String getPersonName() {
        return personName;
    }
    public void setPersonName(String personName) {
        this.personName = personName;
    }
    @Column(name="surname")
    public String getPersonSurname() {
        return personSurname;
    }
    public void setPersonSurname(String personSurname) {
        this.personSurname = personSurname;
    }
    @Override
    public String toString() {
        return "Person [personId=" + personId + ", personName=" + personName
                + ", personSurname=" + personSurname + "]";
    }



}

ManagerBean

@Stateless(name="LRSManager")
public class LRSManagerBean implements LRSManager{
    @Resource(name="lrsDataSource")
    DataSource ds;

    @PersistenceContext(unitName="lrs-unit")
    private EntityManager entityManager;

    @Resource
    private SessionContext sessionContext;

    private static final Log logger = LogFactory.getLog(LRSManagerBean.class);
    @Override
    public void addBook (IBook book) {
        entityManager.persist(book);
    }
    @Override
    public List<IPerson> getAllPersons() {
        System.out.println("Is entityManager not null: "+entityManager!=null);
        List<IPerson> allPersons = null;
        try {
            final Query query = entityManager.createNamedQuery("findAllPersons");
            allPersons = query.getResultList();
        } catch (PersistenceException e) {
            e.printStackTrace();
        }

        return allPersons;
    }

Local interface:

import javax.ejb.Local;
import edu.drg.interfaces.ILRSManager;

@Local
public interface LRSManager extends ILRSManager {

}

I'm trying to access the getAllPersons() method via the Interface manager in a servlet as followss:

@WebServlet("/RetrieveAllPersons")
public class RetrieveAllPersons extends HttpServlet {
    private static final long serialVersionUID = 1L;
    //private ILRSManager manager = LRSManagerFactory.getInstance().getLRSManager();
    @EJB
    private LRSManager manager;
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Log logger = LogFactory.getLog(this.getClass());
        logger.debug("Entering servlet");
        List<IPerson> allPersons = manager.getAllPersons();
        request.setAttribute("allPersons", allPersons);
        logger.debug("Retrieved from persons: "+allPersons);
        RequestDispatcher rd = request.getRequestDispatcher("persons.jsp");
        rd.forward(request, response);
    }

}

However, i have no idea why i'm getting the following exception:

lug 07, 2015 2:12:40 PM org.apache.openejb.core.transaction.EjbTransactionUtil handleSystemException
SEVERE: EjbTransactionUtil.handleSystemException: null
java.lang.NullPointerException
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus(JtaStatusHelper.java:76)
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.isActive(JtaStatusHelper.java:118)
    at org.hibernate.engine.transaction.internal.jta.CMTTransaction.join(CMTTransaction.java:149)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.joinTransaction(AbstractEntityManagerImpl.java:1602)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.postInit(AbstractEntityManagerImpl.java:210)
    at org.hibernate.jpa.internal.EntityManagerImpl.<init>(EntityManagerImpl.java:91)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.internalCreateEntityManager(EntityManagerFactoryImpl.java:345)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:332)
    at org.apache.openejb.assembler.classic.ReloadableEntityManagerFactory.createEntityManager(ReloadableEntityManagerFactory.java:160)
    at org.apache.openejb.persistence.JtaEntityManagerRegistry.getEntityManager(JtaEntityManagerRegistry.java:119)
    at org.apache.openejb.persistence.JtaEntityManager.getEntityManager(JtaEntityManager.java:96)
    at org.apache.openejb.persistence.JtaEntityManager.proxyIfNoTx(JtaEntityManager.java:326)
    at org.apache.openejb.persistence.JtaEntityManager.createNamedQuery(JtaEntityManager.java:289)
    at edu.drg.ejb.LRSManagerBean.getAllPersons(LRSManagerBean.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext$Invocation.invoke(ReflectionInvocationContext.java:192)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext.proceed(ReflectionInvocationContext.java:173)
    at org.apache.openejb.monitoring.StatsInterceptor.record(StatsInterceptor.java:181)
    at org.apache.openejb.monitoring.StatsInterceptor.invoke(StatsInterceptor.java:100)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext$Invocation.invoke(ReflectionInvocationContext.java:192)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext.proceed(ReflectionInvocationContext.java:173)
    at org.apache.openejb.core.interceptor.InterceptorStack.invoke(InterceptorStack.java:85)
    at org.apache.openejb.core.stateless.StatelessContainer._invoke(StatelessContainer.java:227)
    at org.apache.openejb.core.stateless.StatelessContainer.invoke(StatelessContainer.java:194)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler.synchronizedBusinessMethod(EjbObjectProxyHandler.java:308)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler.businessMethod(EjbObjectProxyHandler.java:303)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler._invoke(EjbObjectProxyHandler.java:92)
    at org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:308)
    at com.sun.proxy.$Proxy76.getAllPersons(Unknown Source)
    at edu.drg.servlet.RetrieveAllPersons.doPost(RetrieveAllPersons.java:36)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

lug 07, 2015 2:12:40 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [edu.drg.servlet.RetrieveAllPersons] in context with path [/TestingEJB] threw exception
javax.ejb.EJBException: The bean encountered a non-application exception; nested exception is: 
    java.lang.NullPointerException
    at org.apache.openejb.core.ivm.BaseEjbProxyHandler.convertException(BaseEjbProxyHandler.java:408)
    at org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:312)
    at com.sun.proxy.$Proxy76.getAllPersons(Unknown Source)
    at edu.drg.servlet.RetrieveAllPersons.doPost(RetrieveAllPersons.java:36)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus(JtaStatusHelper.java:76)
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.isActive(JtaStatusHelper.java:118)
    at org.hibernate.engine.transaction.internal.jta.CMTTransaction.join(CMTTransaction.java:149)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.joinTransaction(AbstractEntityManagerImpl.java:1602)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.postInit(AbstractEntityManagerImpl.java:210)
    at org.hibernate.jpa.internal.EntityManagerImpl.<init>(EntityManagerImpl.java:91)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.internalCreateEntityManager(EntityManagerFactoryImpl.java:345)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:332)
    at org.apache.openejb.assembler.classic.ReloadableEntityManagerFactory.createEntityManager(ReloadableEntityManagerFactory.java:160)
    at org.apache.openejb.persistence.JtaEntityManagerRegistry.getEntityManager(JtaEntityManagerRegistry.java:119)
    at org.apache.openejb.persistence.JtaEntityManager.getEntityManager(JtaEntityManager.java:96)
    at org.apache.openejb.persistence.JtaEntityManager.proxyIfNoTx(JtaEntityManager.java:326)
    at org.apache.openejb.persistence.JtaEntityManager.createNamedQuery(JtaEntityManager.java:289)
    at edu.drg.ejb.LRSManagerBean.getAllPersons(LRSManagerBean.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext$Invocation.invoke(ReflectionInvocationContext.java:192)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext.proceed(ReflectionInvocationContext.java:173)
    at org.apache.openejb.monitoring.StatsInterceptor.record(StatsInterceptor.java:181)
    at org.apache.openejb.monitoring.StatsInterceptor.invoke(StatsInterceptor.java:100)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext$Invocation.invoke(ReflectionInvocationContext.java:192)
    at org.apache.openejb.core.interceptor.ReflectionInvocationContext.proceed(ReflectionInvocationContext.java:173)
    at org.apache.openejb.core.interceptor.InterceptorStack.invoke(InterceptorStack.java:85)
    at org.apache.openejb.core.stateless.StatelessContainer._invoke(StatelessContainer.java:227)
    at org.apache.openejb.core.stateless.StatelessContainer.invoke(StatelessContainer.java:194)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler.synchronizedBusinessMethod(EjbObjectProxyHandler.java:308)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler.businessMethod(EjbObjectProxyHandler.java:303)
    at org.apache.openejb.core.ivm.EjbObjectProxyHandler._invoke(EjbObjectProxyHandler.java:92)
    at org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:308)
    ... 25 more

It seems something is wrong with TransactionManager, i'm wondering if i still have to map my entities via hibernate.cfg.xml and add this mapping as the reference to persistence.xml. Also i have noticed what when i'm trying to access my method, the entitymanager removes all my records from the table. I still didn't find anything that could help me on tomee documentation. Any ideas?