package info.ejava.examples.ejb.ejbjpa.ejb;
   
   import info.ejava.examples.ejb.ejbjpa.dao.JPAHotelDAO;
   
   import javax.annotation.PostConstruct;
   import javax.annotation.Resource;
   import javax.ejb.EJB;
   import javax.ejb.EJBException;
   import javax.ejb.Singleton;
  import javax.ejb.Startup;
  import javax.ejb.TransactionManagement;
  import javax.ejb.TransactionManagementType;
  import javax.persistence.EntityManager;
  import javax.persistence.EntityManagerFactory;
  import javax.persistence.PersistenceUnit;
  import javax.transaction.UserTransaction;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * The following EJB provides an example of an EJB using BEAN-managed transactions. 
   */
  @Singleton
  @Startup
  @TransactionManagement(TransactionManagementType.BEAN)
  public class HotelInitEJB implements HotelInitRemote {
      private static final Logger logger = LoggerFactory.getLogger(HotelInitEJB.class);
      
      /**
       * We will still get a resource from the container -- except in this case we
       * will get an EMF rather than an EntityManager. Note the different @PersistenceUnit
       * annotation as well.
       */
      @PersistenceUnit(unitName="ejbjpa-hotel")
      private EntityManagerFactory emf;
      
      @EJB
      HotelMgmtLocal hotelMgmt;
      
      /**
       * We get a UTx injected to control our overall JTA transaction.
       */
      @Resource
      private UserTransaction tx;
      
      @PostConstruct
      public void init() {
          logger.debug("*** HotelInit:init({})", super.hashCode());
          clearAll();
          populate();
          logger.debug("we have {} floors", hotelMgmt.getFloors(0, 0).size());
      }
      
      @Override
      public void clearAll() {
          logger.debug("clearing ejbjpa hotel");
          EntityManager em=emf.createEntityManager();
          try {
              JPAHotelDAO dao = new JPAHotelDAO();
              dao.setEntityManager(em);
              tx.begin();
              em.joinTransaction(); //tells the EM to join the JTA UTx we are managing
              dao.clearAll();
              tx.commit();
              logger.debug("clearing complete");
          } catch (Exception ex) {
              try {
                  tx.rollback();
                  logger.debug("error clearing hotel", ex);
              } catch (Exception ex2) {
                  throw new EJBException(ex2);
              }
              finally {}
          } finally {
              if (em!=null) {
                  em.close();
              }
          }
      }
  
      @Override
      public void populate() {
          logger.debug("populating ejbjpa hotel");
          EntityManager em=emf.createEntityManager();
          try {
              JPAHotelDAO dao = new JPAHotelDAO();
              dao.setEntityManager(em);
              tx.begin();
              em.joinTransaction(); //tells the EM to join the JTA UTx we are managing
              dao.populate();
              tx.commit();
              logger.debug("populate complete");
          } catch (Exception ex) {
              try {
                  tx.rollback();
                  logger.debug("error populating hotel", ex);
              } catch (Exception ex2) {
                  throw new EJBException(ex2);
             }
             finally {}
         } finally {
             if (em!=null) {
                 em.close();
             }
         }
     }
 }