基于Java的在线考试系统

package com.zrm.dao; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.Transaction; import com.zrm.hibernate.HibernateSessionFactory; import com.zrm.model.Student; import com.zrm.model.Subject; import com.zrm.util.Page; public class SubjectDAOImpl implements SubjectDAO{ public void addSubject(Subject subject){ Session session = HibernateSessionFactory.getSession();//获得Session对象 Transaction transaction = null;//声明一个事务对象 try{ transaction = session.beginTransaction();//开启事务 session.save(subject);//保存试题信息 transaction.commit();//提交事务 }catch(Exception ex) { ex.printStackTrace(); transaction.rollback();//事务回滚 } HibernateSessionFactory.closeSession();//关闭Session对象 } public Subject findSubjectByTitle(String subjectTitle) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject as sub where sub.subjectTitle = ?"); query.setString(0, subjectTitle); List list = query.list(); //查询结果保存到list中 HibernateSessionFactory.closeSession(); //关闭Session对象 if(list.size() == 0) { return null; //返回null }else { return (Subject) list.get(0); //返回第一个试题 } } public List<Subject> findSubjectByPage(Page page) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject"); query.setMaxResults(page.getEveryPage());//设置查询记录数 query.setFirstResult(page.getBeginIndex());//设置查询记录起始位置 List list = query.list(); //查询结果保存到list中 HibernateSessionFactory.closeSession();//关闭Session对象 return list; } public int findSubjectCount() { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject"); List list = query.list(); //查询结果保存到list中 int count = list.size(); HibernateSessionFactory.closeSession();//关闭Session对象 return count; } public Subject findSubjectByID(int subjectID) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Subject subject = (Subject) session.get(Subject.class, subjectID); HibernateSessionFactory.closeSession(); //关闭Session对象 return subject; } public void updateSubject(Subject subject) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Transaction transaction = null;//声明一个事务对象 try{ transaction = session.beginTransaction();//开启事务 session.update(subject);//更新试题信息 transaction.commit();//提交事务 }catch(Exception ex) { ex.printStackTrace(); transaction.rollback();//事务回滚 } HibernateSessionFactory.closeSession();//关闭Session对象 } public void deleteSubject(int subjectID) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Subject subject = (Subject) session.get(Subject.class, subjectID); Transaction transaction = null;//声明一个事务对象 try{ transaction = session.beginTransaction();//开启事务 session.delete(subject); transaction.commit();//提交事务 }catch(Exception ex) { ex.printStackTrace(); transaction.rollback();//事务回滚 } HibernateSessionFactory.closeSession();//关闭Session对象 } public List<Subject> likeQueryByTitle(String subjectTitle,Page page) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject as sub where sub.subjectTitle like :title "); query.setString("title","%"+subjectTitle+"%"); query.setMaxResults(page.getEveryPage());//设置查询记录数 query.setFirstResult(page.getBeginIndex());//设置查询记录起始位置 List list = query.list(); //查询结果保存到list中 HibernateSessionFactory.closeSession();//关闭Session对象 return list; } public int findLinkQueryCount(String subjectTitle) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject as sub where sub.subjectTitle like :title "); query.setString("title","%"+subjectTitle+"%"); List list = query.list(); //查询结果保存到list中 int count = list.size(); HibernateSessionFactory.closeSession();//关闭Session对象 return count; } public List<Subject> randomFindSubject(int number) { Session session = HibernateSessionFactory.getSession();//获得Session对象 Query query = session.createQuery("from Subject as sub order by rand()"); query.setMaxResults(number);//设置查询记录数 List list = query.list(); //查询结果保存到list中 HibernateSessionFactory.closeSession();//关闭Session对象 return list; } }