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

import com.rdacorp.petstore.business.dao.ProductDao;
import com.rdacorp.petstore.domain.Category;
import com.rdacorp.petstore.domain.Item;
import com.rdacorp.petstore.domain.Product;

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

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

   public Collection<Product> getProducts(Category category) {
      Category attachedCategory = (Category) em.merge(category);
      attachedCategory.getProducts().size();
      return attachedCategory.getProducts();
   }

   public Collection<Item> getItems(Product product) {
      Product attachedProduct = (Product) em.merge(product);
      attachedProduct.getItems().size();
      return attachedProduct.getItems();
   }

   public Collection<Product> findProducts(String keyword) {
      return em.createQuery("from Product p where lower(p.name) like :keyword").setParameter("keyword",
               "%" + keyword + "%").getResultList();
   }

   public Category findCategory(String code) {
      Category category = (Category) em.createQuery("from Category where code = :code").setParameter("code", code)
               .getSingleResult();
      category.getProducts().size();
      return category;
   }

   public Product findProduct(String code) {
      Product product = (Product) em.createQuery("from Product where code = :code").setParameter("code", code)
               .getSingleResult();
      product.getItems().size();
      return product;
   }

   public Item findItem(String code) {
      Item item = (Item) em.createQuery("from Item where code = :code").setParameter("code", code).getSingleResult();
      return item;
   }
}