简单购物网站模板【小学期】

package jspservlet.dao.impl; import javax.servlet.http.HttpServlet; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import jspservlet.dao.OrderpurDAO; import jspservlet.db.DBConnect; import jspservlet.vo.UserCart; public class OrderpurDAOImpl extends HttpServlet implements OrderpurDAO { @Override public int queryByOrdernum(String name,ArrayList<UserCart> cartlist) throws Exception { // TODO Auto-generated method stub String cartsql="Select price from productinfo where ID=?"; //1.从产品表找到产品价格，算钱 int proamount=0; int totalpur = 0; int j; PreparedStatement pstmt=null; DBConnect dbc=null; PreparedStatement deletepst = null; DBConnect deldbc = null;//从表中删除购买订单 ResultSet rs; String delsql = "delete from cartinfo where username = ?"; //2.在购物车表把此人信息都删掉 String pdessql = "update productinfo set inventory = inventory -'"+ proamount+"' where ID = ?"; //3.修改产品表中库存 DBConnect pdesdbc =null; PreparedStatement pdespst = null; DBConnect buydbc =null; PreparedStatement buypst =null; try{ for(int i = 0; i < cartlist.size();i++) { dbc = new DBConnect() ; proamount = cartlist.get(i).getP_amount(); pstmt = dbc.getConnection().prepareStatement(cartsql) ; pstmt.setString(1,cartlist.get(i).getProductID()); rs = pstmt.executeQuery(); while(rs.next()){ totalpur = totalpur +rs.getInt(1) * proamount; System.out.println("hhhhhhhhhhhhhhh"+totalpur); deldbc = new DBConnect(); pdesdbc= new DBConnect(); pdespst = pdesdbc.getConnection().prepareStatement(pdessql);//商品数量减少 pdespst.setString(1,cartlist.get(i).getProductID()); pdespst.executeUpdate(); System.out.println("hhhhhhhhhhhhhhh商品数量减少"+pdespst.executeUpdate()); } rs.close(); } j =totalpur; String buysql = "insert into buyinfo (username,total) values('"+name+"',"+j+")"; //4.在订单表里生成订单 buydbc = new DBConnect(); buypst = buydbc.getConnection().prepareStatement(buysql); buypst.executeUpdate(); System.out.println("hhhhhhhhhhhhhhh商品数量减少"+buypst.executeUpdate()); deletepst = deldbc.getConnection().prepareStatement(delsql);//购物车相关商品删除 deletepst.setString(1, name); System.out.println("hhhhhhhhhhhhhhh购物车相关商品删除"+deletepst.executeUpdate()); deletepst.executeUpdate(); pstmt.close(); pdespst.close(); deletepst.close(); buypst.close(); }catch(SQLException e) { System.out.println(e.getMessage()); }finally{ dbc.close(); deldbc.close(); pdesdbc.close(); buydbc.close(); } return totalpur; } }