一个struts2+hibernate整合开发的例子(图书管理)

package com.book.dao; import java.util.Iterator; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import com.book.entity.Book; public class BookDao { private Session session = null; private Transaction tr = null; public BookDao() { Configuration config = new Configuration().configure(); SessionFactory factory = config.buildSessionFactory(); session = factory.openSession(); } public void save(Book book){ try{ tr = session.beginTransaction(); session.save(book); tr.commit(); }catch(RuntimeException re){ if(null!=tr){tr.rollback();} throw re; }finally{ session.close(); } } public void update(Book book){ try{ tr = session.beginTransaction(); session.update(book); tr.commit(); }catch(RuntimeException re){ if(null!=tr){tr.rollback();} throw re; }finally{ session.close(); } } public void delete(Book book){ try{ tr = session.beginTransaction(); session.delete(book); tr.commit(); }catch(RuntimeException re){ if(null!=tr){tr.rollback();} throw re; }finally{ session.close(); } } public Book queryById(String id){ Book book = null; String sql = "from Book where id = ?"; Query query = session.createQuery(sql); query.setString(0, id); Iterator it = query.list().iterator(); while(it.hasNext()){ book = (Book) it.next(); } return book; } public List queryAll(){ List list = null; String sql = "from Book"; Query query = session.createQuery(sql); list = query.list(); session.close(); return list; } }