小郡肝火锅点餐系统代码实现(部分)

项目结构：

Java代码实现部分 ：

Food.java

package bean;

import java.math.BigDecimal;

public class Food {
    private int id;                //  主键
    private String foodname;       //  菜名
    private int type_id;           //  菜系
    private  String descript;      //  描述
    private BigDecimal price;             //  价格
    private  int saling;           //  在售
    private String img;            //图片

    public String getDescript() {
        return descript;
    }

    public void setDescript(String deccript) {
        this.descript = deccript;
    }

    public String getFoodname() {
        return foodname;
    }

    public void setFoodname(String foodname) {
        this.foodname = foodname;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getImg() {
        return img;
    }

    public void setImg(String img) {
        this.img = img;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public int getSaling() {
        return saling;
    }

    public void setSaling(int saling) {
        this.saling = saling;
    }

    public int getType_id() {
        return type_id;
    }

    public void setType_id(int type_id) {
        this.type_id = type_id;
    }
}

OrderDao.java

package dao;

import bean.Order;

import java.util.List;

public interface OrderDao{

    void addOrder(Order order) throws Exception;

    Order findUF(Order order) throws Exception ;

    List<Order> findUserId(String userId) throws Exception;
    Order findById(String id) throws Exception;
    void removeOrder(int id) throws Exception;

}

O'r'de'r'DaoImpl.java

package dao.daoImpl;


import bean.Food;
import bean.Order;
import dao.FoodDao;
import dao.OrderDao;
import util.C3P0Util;

import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

public class OrderDaoImpl implements OrderDao {

    FoodDao  foodDao = new FoodDaoImpl();

    @Override
    public void addOrder(Order order) throws Exception {
        //查找是否该用户已经添加了这道菜
        Order sc = this.findUF(order);

        if(sc == null){
            //该用户还没有添加这道菜
            String sql = "INSERT INTO `xiaojungan`.`t_order`(`food_id`,`user_id`,`table_id`,`food_account`) VALUES(?,?,?,?)";

            try(
                    Connection conn = C3P0Util.getConnection();
                    PreparedStatement ps = conn.prepareStatement(sql);
            ) {
                ps.setInt(1,order.getFood_id());
                ps.setInt(2,order.getUser_id());
                ps.setInt(3,order.getTable_id());
                ps.setInt(4,order.getFood_account());

                ps.executeUpdate();
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException("添加失败！");
            }
        }else{ //已经添加这道菜，则更新数量
            String sql = "UPDATE `xiaojungan`.`t_order` SET `food_account` = "+ sc.getFood_account()+"" +
                    "+1 WHERE id="+sc.getId();
            System.out.println(sql);
            try(
                    Connection conn = C3P0Util.getConnection();
                    PreparedStatement ps = conn.prepareStatement(sql);
            ) {
                ps.executeUpdate();
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException("添加失败！");
            }
        }


    }

    @Override
    public Order findUF(Order order) throws Exception {

        String sql = "select * from t_order where user_id=? and food_id=?";

        Order s = null;

        try(
                Connection conn = C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql);
        ) {
            ps.setInt(1,order.getUser_id());
            ps.setInt(2,order.getFood_id());
            try(
                    ResultSet rs = ps.executeQuery();
            ){
                if(rs.next()) {
                    s = new Order();

                    s.setId(rs.getInt(1));
                    s.setFood_id(rs.getInt(2));
                    s.setUser_id(rs.getInt(3));
                    s.setFood_account(rs.getInt(4));
                    Food b = foodDao.findFood_id(order.getFood_id());
                    BigDecimal sellingPrice = b.getPrice();
                    String foodName = b.getFoodname();
                    s.setPrice(sellingPrice);
                    s.setFoodName(foodName);
                    //计算总价
                    s.setTotalPrice(sellingPrice.multiply(BigDecimal.valueOf(s.getFood_account())));

                    System.out.println("s:" + s);
                }
            }catch (Exception e){
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return s;

    }

    @Override
    public  List<Order> findUserId(String userId) throws Exception {
        String sql = "select * from t_order where user_id=?";
        List<Order> shopCartList = new ArrayList<>();
        try(
                Connection conn = C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql)
        ) {
            ps.setInt(1, Integer.parseInt(userId));
            try (
                    ResultSet rs = ps.executeQuery()
            ) {

                //将查询出的结果数据封装到List对象中
                while(rs.next()){
                    Order s = new Order();

                    s.setId(rs.getInt(1));
                    s.setFood_id(rs.getInt(2));
                    s.setUser_id(rs.getInt(3));
                    s.setTable_id(rs.getInt(4));
                    s.setFood_account(rs.getInt(5));
                    Food b = foodDao.findFood_id(s.getFood_id());
                    BigDecimal sellingPrice = b.getPrice();
                    String foodName = b.getFoodname();
                    s.setPrice(sellingPrice);
                    s.setFoodName(foodName);
                    //计算总价
                    s.setTotalPrice(sellingPrice.multiply(BigDecimal.valueOf(s.getFood_account())));

                    shopCartList.add(s);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        return shopCartList;
    }
    public Order findById(String id) throws Exception {
        String sql = "select * from t_order where id=?";

        Order s = null;

        try(
                Connection conn = C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql)
        ) {
            ps.setInt(1, Integer.valueOf(id));

            try (
                    ResultSet rs = ps.executeQuery()
            ) {
                //将查询出的结果数据封装到Order对象中
                if(rs.next()){
                    s = new Order();
                    s.setId(rs.getInt(1));
                    s.setFood_id(rs.getInt(2));
                    s.setUser_id(rs.getInt(3));
                    s.setTable_id(rs.getInt(4));
                    s.setFood_account(rs.getInt(5));
                    Food b = foodDao.findFood_id(s.getFood_id());
                    BigDecimal sellingPrice = b.getPrice();
                    String foodName = b.getFoodname();
                    s.setPrice(sellingPrice);
                    s.setFoodName(foodName);
                    //计算总价
                    s.setTotalPrice(sellingPrice.multiply(BigDecimal.valueOf(s.getFood_account())));
                    return s;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        return s;
    }
    @Override
    public void removeOrder(int id) throws Exception {
        String sql = "DELETE FROM `xiaojungan`.`t_order` WHERE id=?";

        try(
                Connection conn = C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql);
        ) {
            ps.setInt(1, id);

            ps.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException("移除失败！");
        }
    }
}

OrderService.java

package service;

import bean.Order;

import java.util.List;

public interface OrderService {
    void addOrder(Order order) throws Exception ;

    List<Order> findByUserId(String usr_id) throws Exception;
    Order findById(String id) throws Exception;

    void clear();

    void removeOrder(String[] orders);


}

OrderServiceImpl.java

package service.serviceImpl;


import bean.Order;
import dao.OrderDao;
import dao.daoImpl.OrderDaoImpl;
import service.OrderService;

import java.math.BigDecimal;
import java.util.List;

public class OrderServiceImpl implements OrderService {

    BigDecimal totalPrice;
    private OrderDao orderDao = new OrderDaoImpl();

    @Override
    public void addOrder(Order order) throws Exception {
        orderDao.addOrder(order);
    }

    @Override
    public List<Order> findByUserId(String user_id) throws Exception {
        List<Order> orderList = orderDao.findUserId(user_id);
        return orderList;
    }

    @Override
    public void removeOrder(String[] orders) {
        //遍历数据
        for(int i=0;i<orders.length;i++) {
            //移除
            int shopId=Integer.valueOf(orders[i]);
            try {
                orderDao.removeOrder(shopId);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public Order findById(String id) throws Exception {
        Order order = orderDao.findById(id);
        return order;
    }
    @Override
    public void clear() {

    }
}

 OrderServlet.java

package servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

    @WebServlet("/OrderServlet")
    public class OrderServlet  extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            doGet(request, response);
        }

        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

            HttpSession session = request.getSession();
            Object user = session.getAttribute("user");

            if(user != null){
                //用户登陆
                response.sendRedirect("/order.html");

            }else if(user == null){
                //未登录
                response.getWriter().write("请先登录！！1秒后转到登陆界面");
                response.setHeader("refresh", "1;url=" + request.getContextPath()
                        + "/login.html");
            }


        }


}

User.java

package bean;

import java.util.Date;

public class User  {
    private int id;
    private String username;
    private String password;
    private int table_id;
    private int role;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public int getRole() {
        return role;
    }

    public void setRole(int role) {
        this.role = role;
    }

    public int getTable_id() {
        return table_id;
    }

    public void setTable_id(int table_id) {
        this.table_id = table_id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

UserDaoImpl.java

package dao.daoImpl;

import  bean.User;

import  dao.UserDao;
import util.C3P0Util;
import java.sql.ResultSet;
import java.sql.Connection;
import java.sql.PreparedStatement;

public class UserDaoImpl implements UserDao {
    @Override
    public User login(User user)throws Exception {
        String sql = "select * from t_user where username=? and password=?";
        User lo= null;
        try(
                Connection conn =  C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql);
        ) {
            ps.setString(1, user.getUsername());
            ps.setString(2, user.getPassword());
            try(
                    ResultSet rs = ps.executeQuery();
            ){
                if(rs.next()) {
                    lo = new User();
                    lo.setId(rs.getInt(1));
                    lo.setTable_id(rs.getInt(2));
                    lo.setUsername(rs.getString(3));
                    lo.setPassword(rs.getString(4));
                    lo.setRole(rs.getInt(5));
                    System.out.println("lo:" + lo);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return lo;
    }

    @Override
    public void addUser(User user)  throws Exception {
        String sql = "INSERT INTO t_user(username,password)  VALUES(?,?)";
        try (
                Connection conn = C3P0Util.getConnection();
                PreparedStatement ps = conn.prepareStatement(sql)
        ) {
            ps.setString(1, user.getUsername());
            ps.setString(2, user.getPassword());
            ps.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException("注册失败！");
        }
    }
     @Override
     public User findById(int id) throws Exception {
            String sql = "select * from t_user where id=?";

            User u = null;

            try(
                    Connection conn = C3P0Util.getConnection();
                    PreparedStatement ps = conn.prepareStatement(sql)
            ) {
                ps.setInt(1, id);

                try (
                        ResultSet rs = ps.executeQuery()
                ) {
                    //将查询出的结果数据封装到Book对象中
                    if(rs.next()){
                        u = new User();

                        u.setId(rs.getInt(1));
                        u.setTable_id(rs.getInt(2));
                        u.setUsername(rs.getString(3));
                        u.setPassword(rs.getString(4));
                        u.setRole(rs.getInt(5));

                        return u;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }catch (Exception e){
                e.printStackTrace();
            }
            return u;
        }

}