orderdaobean.java

Java EE 5 许多新功能都包含经过修补的 EJB 架构

/*
 * Copyright 2006 Borys Burnayev
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.rdacorp.petstore.business.dao.impl;

import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Date;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.hibernate.StaleObjectStateException;

import com.rdacorp.petstore.business.dao.AddressException;
import com.rdacorp.petstore.business.dao.OrderDao;
import com.rdacorp.petstore.business.dao.OrderException;
import com.rdacorp.petstore.domain.CreditCardCompany;
import com.rdacorp.petstore.domain.Item;
import com.rdacorp.petstore.domain.Order;
import com.rdacorp.petstore.domain.OrderItem;

/**
 * @author Borys Burnayev
 */
@Stateless(name = "OrderDao")
public class OrderDaoBean implements OrderDao {
   @PersistenceContext(unitName = "manager1")
   protected EntityManager em;

   public Order placeOrder(Order order) throws AddressException, OrderException, ConcurrentModificationException {
      Date currentDateTime = new Date();
      order.setOrderTs(currentDateTime);
      order.getPayment().setPaymentTs(currentDateTime);

      for (OrderItem orderItem : order.getOrderItems()) {
         Item item = orderItem.getItem();
         int currentQuantity = item.getAvailableQuantity();
         int newQuantity = currentQuantity - Integer.parseInt(new Long(orderItem.getQuantity()).toString());
         item.setAvailableQuantity(newQuantity > 0 ? newQuantity : 0);
         try {
            em.merge(item);
         }
         catch (StaleObjectStateException e) {
            throw new ConcurrentModificationException();
         }
      }

      em.persist(order);

      return order;
   }

   public Collection<CreditCardCompany> getCreditCardCompanies() {
      return em.createQuery("from CreditCardCompany").getResultList();
   }
}