SSH学生信息管理系统

package service.impl; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.Transaction; import service.StudentsDAO; import db.MyHibernateSessionFactory; import entity.Students; //学生业务逻辑接口的实现类 public class StudentsDAOImpl implements StudentsDAO { //查询所有学生资料 @Override public List<Students> queryAllStudents() { // TODO Auto-generated method stub Transaction tx=null; List<Students> list=null; String hql=""; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx=session.beginTransaction(); hql="from Students"; Query query = session.createQuery(hql); list = query.list(); tx.commit(); return list; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); tx.commit(); return list; }finally{ if (tx!=null) { tx=null; } } } //依靠sid查找所有信息 @Override public Students queryStudentsBySid(String sid) { Transaction tx=null; Students s =null; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx=session.beginTransaction(); s =(Students)session.get(Students.class, sid); tx.commit(); return s; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); tx.commit(); return s; }finally{ if (tx!=null) { tx=null; } } } //添加学生信息 @Override public boolean addStudents(Students s) { // TODO Auto-generated method stub s.setSid(getNewSid());//设置学生的学号 Transaction tx=null; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx = session.beginTransaction(); session.save(s); tx.commit(); return true; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); return false; }finally{ if (tx!=null) { tx=null; } } } //更新学生信息 @Override public boolean updateStudents(Students s) { Transaction tx=null; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx = session.beginTransaction(); session.update(s); tx.commit(); return true; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); tx.commit(); return false; }finally{ if(tx!=null){ tx=null; } } } //删除学生信息根据ID @Override public boolean deleteStudents(String sid) { // TODO Auto-generated method stub Transaction tx=null; //String hql=""; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx = session.beginTransaction(); Students s = (Students)session.get(Students.class, sid); session.delete(s); tx.commit(); return true; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); tx.commit(); return false; }finally{ if(tx!=null){ tx=null; } } } //生成学生学号策略 private String getNewSid(){ Transaction tx=null; String hql=""; String sid=null; try { Session session = MyHibernateSessionFactory.getSessionFaction().getCurrentSession(); tx = session.beginTransaction(); //获取当前学生的最大编号； hql="select max(sid) from Students"; Query query = session.createQuery(hql); sid = (String) query.uniqueResult(); if(sid==null||"".equals(sid)){ //给默认值一个最大编号 sid="S0000001"; }else{ String temp=sid.substring(1);//取后七位 int i = Integer.parseInt(temp);//转成数字 i++; //再还原为字符串 temp = String.valueOf(i); int len = temp.length(); //筹够7位 for(int j=0;j<7-len;j++){ temp="0"+temp; } sid="S"+temp; } tx.commit(); return sid; } catch (Exception e) { // TODO: handle exception e.printStackTrace(); tx.commit(); return null; }finally{ if (tx!=null) { tx=null; } } } }