package ejava.examples.asyncmarket.jpa;
   
   import java.util.List;
   import java.util.Map;
   
   import javax.persistence.EntityManager;
   import javax.persistence.Query;
   
   import ejava.examples.asyncmarket.bo.Order;
  import ejava.examples.asyncmarket.dao.OrderDAO;
  
  public class JPAOrderDAO implements OrderDAO {
      private EntityManager em;
  
      public void setEntityManager(EntityManager em) {
          this.em = em;
      }
  
      public Order createOrder(Order order) {
          em.persist(order);
          return order;
      }
  
      public Order getOrder(long orderId) {
          return em.find(Order.class, orderId);
      }
  
      @SuppressWarnings("unchecked")
      public List<Order> getOrdersforItem(long itemId, int index, int count) {
          return em.createNamedQuery("AsyncMarket_getOrdersForItem")
                          .setParameter("itemId", itemId)
                          .setFirstResult(index)
                          .setMaxResults(count)
                          .getResultList();
      }
  
      @SuppressWarnings("unchecked")
      public List<Order> getOrders(int index, int count) {
          return em.createNamedQuery("AsyncMarket_getOrders")
                   .getResultList();
      }
  
      public Order updateOrder(Order order) {
          return em.merge(order);
      }
  
      @SuppressWarnings("unchecked")
      public List<Order> getOrders(
          String queryString, Map<String, Object> params, int index, int count) {
          Query query = em.createQuery(queryString)
                          .setFirstResult(index)
                          .setMaxResults(count);
          if (params != null) {
              for (String name: params.keySet()) {
                  query.setParameter(name, params.get(name));
              }
          }
          return query.getResultList();
      }
  }