二 Hibernate 改写学生管理系统的业务功能

public class StudentDaoImpl implements StudentDao { @Override
/**
* 查询所有学生
*
* @throws SQLException
*/
public List<Student> findAll() throws SQLException {
Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
// HQL查询,面向对象的查询语言，from Student
Query query = session.createQuery("from Student");
List<Student> list = query.list();
transaction.commit();
session.close();
return list;
} @Override
/**
* 需要添加到数据库的学生
*/
public void insert(Student student) throws SQLException {
Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
// HQL查询,面向对象的查询语言
session.save(student);
transaction.commit();
session.close();
} @Override
/**
* 根据id删除学生
*/
public void delete(int sid) throws SQLException {
Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
// HQL查询,面向对象的查询语言
Student student = session.get(Student.class, sid);
session.delete(student);
transaction.commit();
session.close();
} /**
* 根据id查询单个学生
*
* @throws SQLException
*/
@Override
public Student findStudentById(int sid) throws SQLException { Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
// HQL查询,面向对象的查询语言
Student student = session.get(Student.class, sid);
transaction.commit();
session.close();
return student;
} @Override
/**
* 更新学生到数据库
*/
public void Update(Student stu, int sid) throws SQLException { Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
stu.setSid(sid);
session.saveOrUpdate(stu);
transaction.commit();
session.close();
} @Override
/**
* 模糊查询的DAO层实现
*/
public List<Student> SearchStident(String sname, String sgender) throws SQLException {
DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Student.class);
Object[] obj = { null, "男", "女" };
detachedCriteria.add(Restrictions.like("sname", "%" + sname + "%"));
detachedCriteria.add(Restrictions.in("gender", obj)); Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction(); Criteria criteria = detachedCriteria.getExecutableCriteria(session);
List<Student> list = criteria.list(); transaction.commit();
session.close();
return list;
} @Override
/**
* 分页查询，查询当前页的学生数据并封装成集合
*/
public List<Student> findStudentByPage(int currentPage) throws SQLException {
Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
criteria.setFirstResult(PAGE_SIZE * (currentPage - 1));//起始位置
criteria.setMaxResults(PAGE_SIZE);//每页多少条记录
List<Student> list = criteria.list();
return list;
/*QueryRunner runner = new QueryRunner(JDBCUtil02.getDataSource());
// 第一个？返回记录数量，第二个？偏移量
// 第n页 ： 5,5*n-1
return runner.query("select * from students limit ? offset ?", new BeanListHandler<Student>(Student.class),
PAGE_SIZE, PAGE_SIZE * (currentPage - 1));*/
} @Override
/**
* 查询学生记录数
*/
public int findCount() throws SQLException {
Session session = HibernateUtils.oppenSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
criteria.setProjection(Projections.rowCount());
Long num = (Long) criteria.uniqueResult();
return num.intValue();
}}