packagecom.king.dao.user;importcom.king.pojo.User;importjava.sql.Connection;importjava.sql.SQLException;//面向接口编程，接口是一种约束,要用对应类去实现publicinterfaceUserDao{//得到要登陆的用户publicUsergetLoginUser(Connectionconnection,Stringusercode)throwsSQLException;}
packagecom.king.service.user;importcom.king.dao.BaseDao;importcom.king.dao.user.UserDao;importcom.king.dao.user.UserDaoImpl;importcom.king.pojo.User;importjava.sql.Connection;importjava.sql.SQLException;publicclassUserServiceImplimplementsUserService{//业务层都会调用dao层，所以要引入dao层privateUserDaouserDao;publicUserServiceImpl(){userDao=newUserDaoImpl();}publicUserlogin(StringuserCode,Stringpassword){Connectionconnection=null;Useruser=null;try{connection=BaseDao.getConnection();//通过业务层调用对应的dao层user=userDao.getLoginUser(connection,userCode);}catch(SQLExceptionthrowables){throwables.printStackTrace();}finally{BaseDao.closeResource(connection,null,null);}returnuser;}}