java简单的购物车系统

package dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import dbutil.DBUtil; import bean.ShoppingBean; import bean.UserBean; public class Dao { private static Connection con=null; private static PreparedStatement ps=null; private static ResultSet rs=null; public UserBean getByName(String name,String pass){ UserBean bean=null; con=DBUtil.getcon(); String sql="select password from manager where username=? and password=?"; try { ps=con.prepareStatement(sql); ps.setString(1, name); ps.setString(2, pass); rs=ps.executeQuery(); while(rs.next()){ bean=new UserBean(); bean.setPassword(rs.getString("password")); bean.setUsername(rs.getString("name")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return bean; } public boolean insertUser(UserBean bean){ boolean flag=false; con=DBUtil.getcon(); String sql="insert into manager values(?,?)"; try { ps=con.prepareStatement(sql); ps.setString(1, bean.getUsername()); ps.setString(2, bean.getPassword()); int count=ps.executeUpdate(); if(count>0) flag=true; } catch (SQLException e) { e.printStackTrace(); } return flag; } public ArrayList<ShoppingBean> SelectAll(){ ArrayList<ShoppingBean> list=new ArrayList<ShoppingBean>(); con=DBUtil.getcon(); ShoppingBean bean=null; String sql="select * from buycard"; try { ps=con.prepareStatement(sql); rs=ps.executeQuery(); while(rs.next()){ bean=new ShoppingBean(); bean.setBid(rs.getInt("bid")); bean.setBname(rs.getString("bname")); bean.setBinfo(rs.getString("binfo")); bean.setBprice(rs.getFloat("bprice")); bean.setBface(rs.getString("bface")); list.add(bean); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ DBUtil.CloseAll(con, ps, rs); } return list; } public ShoppingBean getByBid(int bid){ ShoppingBean bean=null; con=DBUtil.getcon(); String sql="select * from buycard where bid=?"; try { ps=con.prepareStatement(sql); ps.setInt(1, bid); rs=ps.executeQuery(); while(rs.next()){ bean=new ShoppingBean(); bean.setBid(rs.getInt("bid")); bean.setBname(rs.getString("bname")); bean.setBinfo(rs.getString("binfo")); bean.setBprice(rs.getFloat("bprice")); bean.setBface(rs.getString("bface")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return bean; } }