categorydaoimpl.java

达内网上购物系统

package org.whatisjava.dang.dao.hibernate;

import java.util.List;

import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.whatisjava.dang.dao.CategoryDao;
import org.whatisjava.dang.domain.Category;
import org.whatisjava.dang.util.DaoException; 

public class CategoryDaoImpl implements CategoryDao {
	private static Logger logger = Logger.getLogger(CategoryDaoImpl.class);

	public Category findById(Integer id, boolean withSub) throws DaoException {
		Session session = HbSessionFactory.getSession();
		try {
			String hql = withSub ? "from Category c left outer join fetch c.subCategory where c.id=?"
					: "from Category c where c.id=?";
			session = HbSessionFactory.getSession();
			Query query = session.createQuery(hql);
			query.setParameter(0, id);
			List<?> list = query.list();
			if (list.size() > 0) {
				return (Category) list.get(0);
			}
			throw new DaoException("无法找到指定Id的分类");
		} catch (HibernateException e) {
			logger.error("", e);
			throw new DaoException("", e);
		} finally {
			HbSessionFactory.closeSession();
		}
	}

	public List<?> findByParentId(Integer parentId) throws DaoException {
		Session session = HbSessionFactory.getSession();
		try {
			String hql = "from Category c where c.parentId=?";
			session = HbSessionFactory.getSession();
			Query query = session.createQuery(hql);
			query.setParameter(0, parentId);
			List<?> list = query.list();
			return list;
		} catch (HibernateException e) {
			logger.error("", e);
			throw new DaoException("", e);
		} finally {
			HbSessionFactory.closeSession();
		}
	}

	public Category findThreeLevelById(Integer id) throws DaoException {
		Session session = HbSessionFactory.getSession();
		try {
			session = HbSessionFactory.getSession();
			Query query = session
					.createQuery("from Category c left outer join fetch c.subCategory subC "
							+ "left outer join fetch subC.subCategory where c.id=?");
			query.setParameter(0, id);
			List<?> list = query.list();
			if (list.size() > 0) {
				return (Category) list.get(0);
			}
			throw new DaoException("无法找到指定Id的分类");
		} catch (HibernateException e) {
			logger.error("", e);
			throw new DaoException("", e);
		} finally {
			HbSessionFactory.closeSession();
		}
	}

}