productdaoimpl.java

java学习的必要的资料,servlet的说明很好

package com.estore.struts.daoimpl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;

import com.estore.struts.Globals;
import com.estore.struts.dao.ProductDao;
import com.estore.struts.entity.Catalog;
import com.estore.struts.entity.Product;
import com.estore.struts.utils.HibernateSessionFactory;
import com.estore.struts.utils.StoreException;

public class ProductDaoImpl implements ProductDao {

	public Collection<Product> findProducts() throws StoreException {
		List<Product> products = new ArrayList<Product>();
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			products = session.createQuery("from Product").list();
			tx.commit();
			return products;
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	public Product getProductByID(Integer id) throws StoreException {
		Product product = new Product();
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			product = (Product) session.get(Product.class, id);
			return product;
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	//此方法是从数据库中获得当前页面要实现的结果;
	public Collection<Product> getProductsByPages(Integer page)
			throws StoreException {
		List<Product> products = new ArrayList<Product>();
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			products = session.createQuery(
					"from Product p order by p.productid")
					.setFirstResult((page - 1) * Globals.PAGE_SIZE)
					.setMaxResults(Globals.PAGE_SIZE)
					.list();
			tx.commit();
			return products;
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.estore.struts.dao.ProductDao#getProudctCount()
	 * 从数据库中查找商品的个数;
	 */
	public int getProudctCount() throws StoreException {
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			return Integer.parseInt(String.valueOf(session.createQuery(
					"select count(*) from Product").uniqueResult()));
		} catch (Exception ex) {
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.estore.struts.dao.ProductDao#searchProduct(java.lang.String,
	 *      java.lang.String) 使用模糊查询去数据库中取得用户想要的信息; 根据不同的查询规则来匹配数据库中不同的字段;
	 */
	public Collection<Product> searchProduct(String text, String rule) {
		List<Product> searchproducts = new ArrayList<Product>();
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();

			if (rule.equalsIgnoreCase("author")) {
				searchproducts = session.createQuery(
						"from Product p where p.author like:author").setString(
						"author", "%" + text + "%").list();
			} else if (rule.equalsIgnoreCase("bookname")) {
				searchproducts = session.createQuery(
						"from Product p where p.name like:bookname").setString(
						"bookname", "%" + text + "%").list();
			} else if (rule.equalsIgnoreCase("printer")) {
				searchproducts = session.createQuery(
						"from Product p where p.printer like:printer")
						.setString("printer", "%" + text + "%").list();
			} else if (rule.equalsIgnoreCase("createtime")) {
				searchproducts = session.createQuery(
						"from Product p where p.createtime like:createtime")
						.setString("createtime", "%" + text + "%").list();
			} else if (rule.equalsIgnoreCase("catalog")) {
				Catalog catalog = (Catalog) session.createQuery(
				"from Catalog c where c.catalogid=:id")
				.setInteger("id", Integer.parseInt(text)).uniqueResult();
				searchproducts.addAll(catalog.getProducts());
			} 

			tx.commit();
			return searchproducts;
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	public Catalog getCatalog(int id) throws StoreException {
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			Catalog catalog = (Catalog) session.get(Catalog.class,id);
			return catalog;
		} catch (Exception ex) {
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}
	
	public void addProduct(Product product) {
		
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			session.save(product);
			tx.commit();
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}
	
	public void deleteProduct(Product product) {
		
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			session.delete(product);
			tx.commit();
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
	}

	public void updateProduct(Product product) {
		Transaction tx = null;
		Session session = null;
		try {
			session = HibernateSessionFactory.getSession();
			tx = session.beginTransaction();
			session.saveOrUpdate(product);
			tx.commit();
		} catch (Exception ex) {
			tx.rollback();
			throw new StoreException(ex);
		}finally {
			session.close();
		}
		
	}

}