public void add(Maintenance maintenance) {
   try {
     session = HibernateUtil.getSessionFactory().openSession();
     session.beginTransaction();
     session.save(maintenance);
     session.getTransaction().commit();
   } catch (Exception e) {
     System.err.println("Can`t add object to database\n " + e);
   } finally {
     if (session != null) session.close();
   }
 }
  public List<Maintenance> getAll() {

    List<Maintenance> result = null;
    try {
      session = HibernateUtil.getSessionFactory().openSession();
      Criteria criteria = session.createCriteria(Maintenance.class);
      result = (List<Maintenance>) criteria.list();
      session.getTransaction().commit();
    } catch (Exception e) {
      System.err.println("Error in getting information from \"Capital\"\n" + e);
    } finally {
      if (session != null) session.close();
    }
    return result;
  }
 public void delete(int id) {
   try {
     session = HibernateUtil.getSessionFactory().openSession();
     session.beginTransaction();
     Maintenance capital = (Maintenance) session.get(Maintenance.class, id);
     if (capital == null) {
       throw new NullPointerException();
     }
     session.delete(capital);
     session.getTransaction().commit();
   } catch (NullPointerException e) {
     System.err.println("There are not any item with this id\n" + e);
   } catch (Exception e) {
     System.err.println("Can`t delete this item\n" + e);
   } finally {
     if (session != null) session.close();
   }
 }
  public void update(Maintenance maintenance, int id) {

    try {
      session = HibernateUtil.getSessionFactory().openSession();
      session.beginTransaction();
      Maintenance updateItem = (Maintenance) session.get(Maintenance.class, id);
      if (updateItem == null) throw new NullPointerException();
      updateItem.setDate(maintenance.getDate());
      updateItem.setNumberEquipment(maintenance.getNumberEquipment());
      updateItem.setKindMaintenance(maintenance.getKindMaintenance());
      session.update(updateItem);
      session.getTransaction().commit();
    } catch (NullPointerException e) {
      System.err.println("Can`t find item with this id\n" + e);
    } catch (Exception e) {
      System.err.println("Can`t update this item\n" + e);
    } finally {
      if (session != null) session.close();
    }
  }
  public Maintenance get(int id) {

    Maintenance findItem = new Maintenance();
    try {
      session = HibernateUtil.getSessionFactory().openSession();
      session.beginTransaction();
      findItem = (Maintenance) session.get(Maintenance.class, id);
      if (findItem == null) {
        throw new NullPointerException();
      }
      session.getTransaction().commit();
    } catch (NullPointerException e) {
      System.err.println("There are not any item with this id");
      findItem = new Maintenance();
    } catch (Exception e) {
      System.err.println("Can`t find this item " + e);
    } finally {
      if (session != null) session.close();
    }
    return findItem;
  }