Java EE 6: How to add web module on top of application client
public static void main(String[] args) {
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("CoreInPU");
    EntityManager em = emf.createEntityManager();
    EntityDAO entityDAOClient = new EntityDAOClient(em);
    Main pgm = new Main();
    try {
        process(entityDAOClient);
    } catch (Exception e) {
        logger.fatal("", e);
    }finally{
        em.close();
        emf.close();
    }
}

public void process(EntityDAO entityDAO){
    validatePDF(List<pdfFiles>);
    processPDF(List<pdfFiles>, entityDAO);
    createPrintJob(List<pdfFiles>, entityDAO);
}

public void processPDF(List<pdfFiles>, EntityDAO entityDAO){
    for(File file : pdfFiles){
        entityDAO.create(file);
    }
}

public interface EntityDAO {
    public <T> T create(T t);
    public <T> T find(Class<T> type, Object id);
    public List findWithNamedQuery(String queryName);
    public List findWithNamedQuery(String queryName, int resultLimit);

}

public class EntityDAOClient implements EntityDAO {

    private EntityManager em;

    private static Logger logger = Logger.getLogger(EntityDAOClient.class);

    public EntityDAOClient(EntityManager em) {
        this.em = em;
    }

    @Override
    public <T> T create(T t){
        em.getTransaction().begin();
        em.persist(t);
        em.getTransaction().commit();
        return t;
    }

    @Override
    public <T> T find(Class<T> type, Object id){
        em.getTransaction().begin();
        T t = em.find(type, id);
        em.getTransaction().commit();
        return t;
    }
    ...
}

<persistence-unit name="CoreInPU" transaction-type="RESOURCE_LOCAL">
   <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
   <class>com.wf.docsys.core.entity.Acknowledgement</class>
   <class>com.wf.docsys.core.entity.PackageLog</class>
   <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/core"/>
      <property name="javax.persistence.jdbc.password" value="root"/>
      <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
      <property name="javax.persistence.jdbc.user" value="xxxx"/>
      <property name="eclipselink.ddl-generation" value="create-tables"/>
   </properties>
</persistence-unit>

@Stateless
@LocalBean
public class CoreEJB implements EntityDAO{

    @PersistenceContext(unitName = "CoreInWeb-ejbPU")
    private EntityManager em;

    //@Override
    public <T> T create(T t) {
        em.persist(t);
        return t;
    }

    //@Override
    public <T> T find(Class<T> type, Object id) {
        return em.find(type, id);
    }

    ...
}

@ManagedBean
@RequestScoped
public class Bean {

   @EJB
   private CoreEJB coreEJB;


   public Bean() {

   }

   public void runAppClientMainProcess() {
       //The web interface can also kick off the same process as the app client
       process(coreEJB);
   }

   // ...
}

@Stateless
public class SomeEJB {

    @PersistenceUnit(unitName="someWebPU")
    private EntityManagerFactory emf;

    @PostConstruct
    public void init() {
        EntityUtil.newInstance(emf);
    }

    public void create(Some some) {
        EntityUtil.create(some);
    }

    // ...
}

public interface SomeDAO {

    public void save(Some some);
    // ...
}

public class SomeDAOClient implements SomeDAO {

    private EntityManager em;

    public SomeDAO(EntityManager em) {
        this.em = em;
    }

    public void save(Some some) {
        em.getTransaction().begin();
        em.persist(some);
        em.getTransaction().commit();
    }

    // ...
}

public static void main(String[] args) throws Exception {
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("someClientPU");
    EntityManager em = emf.createEntityManager();
    SomeDAO someDAO = new SomeDAOClient(em);

    try {
        Some some = new Some();
        some.setFoo("foo");
        someDAO.save(some);
    } finally {
        em.close();
        emf.close();
    }
}

@Stateless
public class SomeDAOEJB implements SomeDAO {

    @PersistenceContext(unitName="someWebPU")
    private EntityManager em;

    public void save(Some some) {
        em.persist(some);
    }

    // ...
}

@ManagedBean
@RequestScoped
public class Bean {

    @EJB
    private SomeDAO someDAO;
    private Some some;

    public Bean() {
        some = new Some();
    }

    public void save() {
        someDAO.save(some);
    }

    // ...
}

//This class works as is in both javaEE and client.
//There is no need of managedbean in CDI.
//This class can be accessed in jsf using EL #businessProcessor
@Singleton  @Named
public class BusinessProcessor
{
private @Inject EntityDAO entityDAO; // CDI will inject an implementation of EntityDao.
//In our case there is only one impl for client as well as JavaEE

// CDI will invoke below method on startup. Not used in JavaEE.
// In JavaEE JSF will execute process() directly using Expression Language
public void init(@Observes ContainerInitialized event, @Parameters List parameters){
process(entityDAO);
}

public void process(@Inject EntityDAO entityDAO){
    validatePDF(List);
    processPDF(List, entityDAO);
    createPrintJob(List, entityDAO);
}

public void processPDF(List, EntityDAO entityDAO){
    for(File file : pdfFiles){
        entityDAO.create(file);
    }
}
}

// this class is same for both JavaEE and Client
public class EntityDAOClient implements EntityDAO {

private @Inject EntityManager em;

    private static Logger logger = Logger.getLogger(EntityDAOClient.class);

    @Override
    public  T create(T t){
        em.getTransaction().begin();
        em.persist(t);
        em.getTransaction().commit();
        return t;
    }

    @Override
    public  T find(Class type, Object id){
        em.getTransaction().begin();
        T t = em.find(type, id);
        em.getTransaction().commit();
        return t;
    }
    ...
}

java org.jboss.weld.environment.se.StartMain

public class Main {

    @EJB
    private static CoreMainEJBRemote coreEJBRemote;

    private static Logger logger = Logger.getLogger(Main.class);

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
         coreEJBRemote.process(args[0]);
    }
}

@Stateless
public class CoreMainEJB implements CoreMainEJBRemote, CoreMainEJBLocal {

    @EJB
    private PackageProcessor packageProcessor;

    @Override
    public void process(String configFileName) {
         ...
         //Process config File
         packageProcessor.validatePDF();
         packageProcessor.processPDF();
         ...
    }
}