来源：blog.csdn.net/weixin_44219955

傻瓜式外卖点餐系统（无数据库）

tips：

菜品类(菜品id，菜品名，菜品类型，上架时间，单价，月销售，总数量)管理员类(管理员id，账号，密码)客户类(客户id，客户名，性别，密码，送餐地址，手机号，创建时间)订单类(订单号，订单创建时间，菜品id，购买数，客户id，总价格，订单状态)

说明：菜品类型可自行设计数据类型(int或String)，如1：面食 2：米饭 3：湘菜 …菜品上架时间、客户创建时间、订单创建时间根据添加时间自动分配系统时间订单状态类型为int（0:未支付 1：已支付 2：配送中 3：已完成）

要求实现如下功能：实现不同角色用户登录系统

(1) 管理员登录系统看到如下菜单：

① 添加菜品

② 查看所有菜品信息(包含分页功能)

③ 查看指定类别的菜品信息

④ 根据菜品id修改菜品价格

⑤ 删除指定id的菜品

⑥ 添加客户

⑦ 查看客户列表

⑧ 删除指定id的客户

⑨ 订单列表显示

⑩ 根据订单id修改订单状态

11 退出

(2) 客户登录看到如下菜单：

① 显示所有菜品(按菜品销量从高到低排序输出)

-------->点餐（输入菜品id和购买数量）

② 根据菜品类别显示所有菜品

③ 查看所有订单(当前登录用户的)

④ 修改密码（当前登录用户的）

⑤ 个人信息显示

以上就是全部要求，首先咱们可以先建一个接口，方便对四个管理类进行操作；

package com.softeem.lesson23.test2;import java.util.List;public interface DAO<T> { void insert(T t); T findById(String id); List<T> findAll(); void delete(String id);}

一、再根据要求，先把四个类的属性类建立起来：

1. Admin类（管理员类）

package com.softeem.lesson23.test2;public class Admin { private String aID; private String account; private String apwd; public Admin() { // TODO Auto-generated constructor stub } public Admin(String aID, String account, String apwd) { super(); this.aID = aID; this.account = account; this.apwd = apwd; } public String getaID() { return aID; } public void setaID(String aID) { this.aID = aID; } public String getAccount() { return account; } public void setAccount(String account) { this.account = account; } public String getApwd() { return apwd; } public void setApwd(String apwd) { this.apwd = apwd; } @Override public String toString() { return "Admin [aID=" + aID + ", account=" + account + ", apwd=" + apwd + "]"; } }

2. Dishes类（菜品类）

package com.softeem.lesson23.test2;import java.time.LocalDate;public class Dishes { private String dID; private String dname; private String dtype; private LocalDate dtime; private double price; private int dsales; private int dstocks; public Dishes() { // TODO Auto-generated constructor stub } public Dishes(String dID, String dname, String dtype, LocalDate dtime, double price, int dsales, int dstocks) { super(); this.dID = dID; this.dname = dname; this.dtype = dtype; this.dtime = dtime; this.price = price; this.dsales = dsales; this.dstocks = dstocks; } public String getdID() { return dID; } public void setdID(String dID) { this.dID = dID; } public String getDname() { return dname; } public void setDname(String dname) { this.dname = dname; } public String getDtype() { return dtype; } public void setDtype(String dtype) { this.dtype = dtype; } public LocalDate getDtime() { return dtime; } public void setDtime(LocalDate dtime) { this.dtime = dtime; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public int getDsales() { return dsales; } public void setDsales(int dsales) { this.dsales = dsales; } public int getDstocks() { return dstocks; } public void setDstocks(int dstocks) { this.dstocks = dstocks; } @Override public String toString() { return "Dishes [菜品id：" + dID + ", 菜品名：" + dname + ", 菜品类型：" + dtype + ", 上架时间：" + dtime + ", 单价：" + price + ", 月销量：" + dsales + ", 总数量：" + dstocks + "]"; }}

3. Order类（订单类）

package com.softeem.lesson23.test2;import java.time.LocalDateTime;public class Order { private String OrderID; private LocalDateTime utime; private Dishes dishes; private int Ordernum; private String uID; private Double Orderprice; private int OrderValue; public Order() { // TODO Auto-generated constructor stub } public Order(String orderID, LocalDateTime utime, Dishes dishes, int ordernum, String uID, Double orderprice, int orderValue) { super(); OrderID = orderID; this.utime = utime; this.dishes = dishes; Ordernum = ordernum; this.uID = uID; Orderprice = orderprice; OrderValue = orderValue; } public String getOrderID() { return OrderID; } public void setOrderID(String orderID) { OrderID = orderID; } public LocalDateTime getUtime() { return utime; } public void setUtime(LocalDateTime utime) { this.utime = utime; } public Double getOrderprice() { return Orderprice; } public void setOrderprice(Double orderprice) { Orderprice = orderprice; } public Dishes getDishes() { return dishes; } public void setDishes(Dishes dishes) { this.dishes = dishes; } public int getOrdernum() { return Ordernum; } public void setOrdernum(int ordernum) { Ordernum = ordernum; } public String getuID() { return uID; } public void setuID(String uID) { this.uID = uID; } public int getOrderValue() { return OrderValue; } public void setOrderValue(int orderValue) { OrderValue = orderValue; } @Override public String toString() { return "Order [OrderID=" + OrderID + ", utime=" + utime + ", dishes=" + dishes + ", Ordernum=" + Ordernum + ", uID=" + uID + ", Orderprice=" + Orderprice + ", OrderValue=" + OrderValue + "]"; }}

4. User类（用户类）

package com.softeem.lesson23.test2;import java.time.LocalDateTime;public class User { private String uID; private String uname; private String usex; private String upwd; private String uadress; private String utel; private LocalDateTime utime; public User() { // TODO Auto-generated constructor stub } public User(String uID, String uname, String usex, String upwd, String uadress, String utel, LocalDateTime utime) { super(); this.uID = uID; this.uname = uname; this.usex = usex; this.upwd = upwd; this.uadress = uadress; this.utel = utel; this.utime = utime; } public String getuID() { return uID; } public void setuID(String uID) { this.uID = uID; } public String getUname() { return uname; } public void setUname(String uname) { this.uname = uname; } public String getUsex() { return usex; } public void setUsex(String usex) { this.usex = usex; } public String getUpwd() { return upwd; } public void setUpwd(String upwd) { this.upwd = upwd; } public String getUadress() { return uadress; } public void setUadress(String uadress) { this.uadress = uadress; } public String getUtel() { return utel; } public void setUtel(String utel) { this.utel = utel; } public LocalDateTime getUtime() { return utime; } public void setUtime(LocalDateTime utime) { this.utime = utime; } @Override public String toString() { return "User [uID=" + uID + ", uname=" + uname + ", usex=" + usex + ", upwd=" + upwd + ", uadress=" + uadress + ", utel=" + utel + ", utime=" + utime + "]"; }}

这一步没什么难度，直接把每一个属性都设置一下，然后设置为私有，注意属性的数据类型，这个很重要，方便后期管理类对其进行操作。

二、属性管理类

这个是整个demo比较难得地方，我的想法是建立Admin属性管理类，Order属性管理类，Dishes属性类，User属性管理类，再在Admin属性管理类里把Order属性管理类，Dishes属性类，User属性管理类先new出来，然后，每个属性管理类实现各自的方法，只需要在Admin属性管理类中调用各个属性管理类的方法，就可以实现通过Admin类管理其他类的数据，但是，每个类需要建一个Map集合，存储各自的元素，此处应该注意每个属性管理类Map的键方便后期对Map进行操作，然后建立菜单类，规定User和Admin能调用的方法。

话不多说，直接上代码，一下代码是通过Admin管理类延伸的，所以先看Admin管理类。

1. Admin管理类

package com.softeem.lesson23.test2;import java.time.LocalDate;import java.time.LocalDateTime;//import java.util.ArrayList;import java.util.Collections;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Scanner;//import java.util.Set;public class AdminSys implements DAO<Admin> { static Map<String, Admin> map = new HashMap<>();// static Set<String> keys = map.keySet(); UserSys u = new UserSys(); OrderSys o = new OrderSys(); DishesSys d = new DishesSys(); Scanner sc = new Scanner(System.in); /** * 添加菜品 */ public void addDishes() { System.out.println("请输入您要添加的菜品:(按照:菜品ID/菜品名/菜品类型/单价/月销量/总数量)"); String str = sc.next(); String[] info = str.split("/"); // if (info.length < 6) { System.out.println("天啦撸，输入失败啦，请重新输入！"); addDishes(); } else { LocalDate dtime = LocalDate.now(); Dishes t = new Dishes(info[0], info[1], info[2], dtime, Double.parseDouble(info[3]), Integer.parseInt(info[4]), Integer.parseInt(info[5])); d.insert(t); System.out.println("小主,恭喜你！添加成功了"); } } /** * 查看所有菜品信息(包含分页功能) */ public void showAllDishes(int pageSize) { List<Dishes> list = d.findAll(); int start = 0; //先写一个死循环，进入else后break掉 while (true) { if (list.size() > (pageSize + start)) { System.out.println(list.subList(start, pageSize + start)); } else { System.out.println(list.subList(start, list.size())); break; } start = start + pageSize; } } /** * 查看指定类别的菜品信息 * */ public void selecBytypeOfAdmin() { System.out.println("请输入您要查询菜品的类别："); String typename = sc.next(); d.selectBytype(typename); } /** * 根据菜品id修改菜品价格 */ public void selectByDishesID() { System.out.println("请输入您要查询的菜品id："); String id = sc.next(); Dishes dish = d.findById(id); if (dish == null) { System.out.println("没有当前id的菜品呢"); } else { System.out.println("当前菜品为：" + dish); System.out.println("请输入新的菜品单价："); double newprice = sc.nextDouble(); Dishes t = new Dishes(dish.getdID(), dish.getDname(), dish.getDtype(), dish.getDtime(), newprice, dish.getDsales(), dish.getDstocks()); d.insert(t); System.out.println("修改成功" + d.findById(t.getdID())); } } /** * 删除指定id的菜品 * * @param args */ public void deleteDishes() { System.out.println("请输入您要删除的菜品id"); String id = sc.next(); d.delete(id); System.out.println("删除成功！！"); } /** * 添加客户 */ public void addUser() { System.out.println("请输入您要添加的用户:按照(id/姓名/性别/密码/送餐地址/手机号)"); String str = sc.next(); String[] info = str.split("/"); if (info.length < 6) { System.out.println("您输入的信息有误，请重新输入...."); addUser(); } else { LocalDateTime utime = LocalDateTime.now(); u.insert(new User(info[0], info[1], info[2], info[3], info[4], info[5], utime)); System.out.println("添加成功"); } } /** * 查看客户列表 */ public void findUser() { List<User> userlist = u.findAll(); for (User user : userlist) { System.out.println(user); } } /** * 根据id查找指定用户 */ public User findUserByid(String id) { return u.findById(id); } /** * 删除指定id的客户 */ public void deleteUserByAdmin() { System.out.println("请输入您要删除的id："); String id = sc.next(); u.delete(id); } /** * 订单列表显示 */ public void showAllOrder() { List<Order> allOrder = o.findAll(); for (Order order : allOrder) { System.out.println(order); } } /** * 根据订单id修改订单状态 */ public void changeOrderValue() { System.out.println("请输入您要修改状态的订单id"); String id = sc.next(); Order order = o.findById(id); if (order == null) { System.out.println("没有当前id的订单，请检查输入"); } else { System.out.println("已找到当前id订单" + order); System.out.println("请输入您要修改的状态：0:未支付 1：已支付 2：配送中 3：已完成"); int value = sc.nextInt(); Order t = new Order(order.getOrderID(), order.getUtime(), order.getDishes(), order.getOrdernum(), order.getuID(), order.getOrderprice(), value); o.insert(t); System.out.println("修改成功了！！！"); } } /** * 显示所有菜品(按菜品销量从高到低排序输出) */ public void showAllDishesByUser() { List<Dishes> list = d.findAll(); Collections.sort(list, (p1, p2) -> p1.getDsales() - p2.getDsales()); System.out.println(list); } /** * 点餐（输入菜品id和购买数量） */ public void shopDishes(User user) { showAllDishesByUser(); System.out.println("请输入您要购买的id和数量：按照(id/数量)"); String str = sc.next(); String[] info = str.split("/"); // 判断输入是否符合要求，不符合则要求重新输入 if (info.length < 2) { System.out.println("输入有误，请重新输入："); shopDishes(user); } else { LocalDateTime l = LocalDateTime.now(); // String orderID, LocalDateTime utime, Dishes dishes, int ordernum, String uID, // Double orderprice,int orderValue Order t = new Order(info[0], l, d.findById(info[0]), Integer.parseInt(info[1]), user.getuID(), o.findById(info[0]).getOrderprice(), o.findById(info[0]).getOrderValue()); o.insert(t); System.out.println("订单已生成！！！" + o.findById(info[0])); } } /** * 根据菜品类别显示所有菜品 */ public void ShowOfTypeByUser() { System.out.println("请输入您要查找的类别："); String str = sc.next(); System.out.println(d.findByType(str)); } /** * 查看所有订单(当前登录用户的) */ public void showAllOrderByUser(User user) { List<Order> list = o.findByuId(user.getuID()); for (Order order : list) { System.out.println(order); } } /** * 修改密码（当前登录用户的） */ public void changePwdByUser(User user) { u.changepwd(user.getuID()); System.out.println("修改成功！！"); } /** * 个人信息显示 */ public void showByUser(User user) { User findById = u.findById(user.getuID()); System.out.println(findById); } //待补充功能，删除管理员 @Override public void delete(String id) { } //待补充功能，添加管理员 @Override public void insert(Admin t) { // TODO Auto-generated method stub } //待补充功能，通过id即账号查找管理员 @Override public Admin findById(String id) { return map.get(id); } //待补充功能，显示所有管理员 @Override public List<Admin> findAll() { // TODO Auto-generated method stub return null; } //先设置系统默认数据 public void addMessage() { map.put("qwl", new Admin("10086", "qwl", "123456")); LocalDate time = LocalDate.now(); Dishes d1 = new Dishes("1", "红烧猪蹄", "肉类", time, 12.5, 20, 30); d.insert(d1); Dishes d2 = new Dishes("2", "鸡公煲", "肉类", time, 21.5, 30, 20); d.insert(d2); Dishes d3 = new Dishes("3", "麻辣香锅", "火锅类", time, 30, 5, 10); d.insert(d3); Dishes d4 = new Dishes("4", "水煮肉片", "肉类", time, 15, 12, 15); d.insert(d4); Dishes d5 = new Dishes("5", "水果沙拉", "水果类", time, 6, 70, 60); d.insert(d5); // String orderID, LocalDateTime utime, Dishes dishes, int ordernum, String uID, // Double orderprice,int orderValue LocalDateTime localdatetime = LocalDateTime.now(); Order o1 = new Order("1", localdatetime, d1, 10, "1001", 60.0, 1); o.insert(o1); Order o2 = new Order("2", localdatetime, d2, 5, "1002", 50.0, 10); o.insert(o2); Order o3 = new Order("3", localdatetime, d3, 5, "1003", 40.0, 5); o.insert(o3); Order o4 = new Order("4", localdatetime, d4, 5, "1004", 30.0, 6); o.insert(o4); Order o5 = new Order("5", localdatetime, d5, 5, "1005", 20.0, 8); o.insert(o5); // String uID, String uname, String usex, String upwd, String uadress, String // utel, LocalDateTime utime User u1 = new User("1001", "张三", "男", "123456", "湖北", "13545286487", localdatetime); u.insert(u1); User u2 = new User("1002", "李四", "男", "234567", "湖南", "15927948976", localdatetime); u.insert(u2); User u3 = new User("1003", "王五", "男", "345678", "江苏", "15927986854", localdatetime); u.insert(u3); User u4 = new User("1004", "刘柳", "女", "456789", "浙江", "18771580860", localdatetime); u.insert(u4); User u5 = new User("1005", "赵琦", "女", "567890", "新疆", "18771580750", localdatetime); u.insert(u5); }}

2. Order属性管理类

package com.softeem.lesson23.test2;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Objects;import java.util.Set;public class OrderSys implements DAO<Order> { static Map<String, Order> ordermap = new HashMap<>(); static List<Order> orderlist = new ArrayList<>(); /** * 新增订单 */ @Override public void insert(Order t) { ordermap.put(t.getOrderID(), t); } /** * 通过订单id查找订单 */ @Override public Order findById(String id) { if (ordermap.get(id) == null) { return null; } else { return ordermap.get(id); } } /** * 通过用户id查询用户的所有订单，并返回一个list集合 * @param uid * @return */ public List<Order> findByuId(String uid) { List<Order> list = new ArrayList<>(); Set<String> keys = ordermap.keySet(); for (String key : keys) { if (Objects.equals(uid, ordermap.get(key).getuID())) { list.add(ordermap.get(key)); } } return list; } /** * 显示所有订单 */ @Override public List<Order> findAll() { Set<String> keys = ordermap.keySet(); for (String key : keys) { orderlist.add(ordermap.get(key)); } return orderlist; } /** * 待完成功能，删除订单 */ @Override public void delete(String id) { // TODO Auto-generated method stub }}

3. User属性管理类

package com.softeem.lesson23.test2;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Scanner;import java.util.Set;//客户id，客户名，性别，密码，送餐地址，手机号，创建时间public class UserSys implements DAO<User> { static Map<String, User> usermap = new HashMap<>(); List<User> list = new ArrayList<>(); Scanner sc = new Scanner(System.in); /** * 添加客户 */ @Override public void insert(User t) { usermap.put(t.getuID(), t); } /** * 查看客户列表 */ @Override public List<User> findAll() { Set<String> keys = usermap.keySet(); for (String str : keys) { list.add(usermap.get(str)); } return list; } /** * 删除指定id的客户 */ @Override public void delete(String id) { if (usermap.get(id) == null) { System.out.println("没有当前id的客户"); } else { System.out.println(usermap.get(id) + "已删除！！！"); usermap.remove(id); } } /** * 修改密码（当前登录用户的） */ public void changepwd(String id) { User user = findById(id); System.out.println("请输入新密码："); String str = sc.next(); User t = new User(user.getuID(), user.getUname(), user.getUsex(), str, user.getUadress(), user.getUtel(), user.getUtime()); usermap.put(id, t); } /** * 通过id查找对应客户 */ @Override public User findById(String id) { if (usermap.get(id) == null) { return null; } else { return usermap.get(id); } }}

4. Dishes属性管理类

package com.softeem.lesson23.test2;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Objects;import java.util.Set;public class DishesSys implements DAO<Dishes> { // 建立一个菜品的map集合，其中菜品的id为map的键，整个菜品对象为map的值 static Map<String, Dishes> dishesmap = new HashMap<>(); Set<String> keys = dishesmap.keySet(); /** * 添加菜品 */ @Override public void insert(Dishes t) { dishesmap.put(t.getdID(), t); } /** * 通过id来寻找菜品 */ @Override public Dishes findById(String id) { if (dishesmap.get(id) == null) { return null; } else { return dishesmap.get(id); } } /** * 根据菜品类型查找菜品 */ public List<Dishes> findByType(String type) { List<Dishes> list = new ArrayList<>(); for (String key : keys) { if (Objects.equals(type, dishesmap.get(key).getDtype())) { list.add(dishesmap.get(key)); } } return list; } /** * 查询所有菜品 */ @Override public List<Dishes> findAll() { List<Dishes> list = new ArrayList<>(); for (String str : keys) { list.add(dishesmap.get(str)); } return list; } public void selectBytype(String typename) { int count = 0; for (String key : keys) { if (Objects.equals(dishesmap.get(key).getDtype(), typename)) { System.out.println(dishesmap.get(key)); count++; } } if (count == 0) { System.out.println("没有当前类别的菜品！"); } } /** * 删除指定id菜品 */ @Override public void delete(String id) { if (dishesmap.get(id) == null) { System.out.println("输入id错误..."); } else { dishesmap.remove(id); } }}

以上基本就是代码的核心部分，剩下的部分就简化很多了，建立一个菜单类，分别对其进行不同调用就行了

三、菜单类

package com.softeem.lesson23.test2;import java.util.Objects;import java.util.Scanner;public class Menu { static AdminSys admin = new AdminSys(); Scanner sc = new Scanner(System.in); public void showMenu() { admin.addMessage(); System.out.println("请输入账号和密码：按照(账号/密码)"); String str = sc.next(); String[] info = str.split("/"); if (info.length < 2) { System.out.println("输入有误，请重新输入："); showMenu(); } else { if (admin.findById(info[0]) != null && Objects.equals(admin.findById(info[0]).getApwd(), info[1])) { adminMenu(); } else if (admin.findUserByid(info[0]) != null && Objects.equals(info[1], admin.findUserByid(info[0]).getUpwd())) { User user = admin.findUserByid(info[0]); userMenu(user); } else { System.out.println("输入有误，请重新输入...."); showMenu(); } } } public void userMenu(User user) { System.out.println("=========欢迎来到订餐系统======="); System.out.println("====【1】点餐================="); System.out.println("====【2】根据菜品类别显示所有菜品==="); System.out.println("====【3】查看所有订单============"); System.out.println("====【4】修改密码==============="); System.out.println("====【5】个人信息显示============"); System.out.println("====【6】退出=================="); System.out.println("请输入您要进行的操作："); String n = sc.next(); switch (n) { case "1": admin.shopDishes(user); userMenu(user); break; case "2": admin.ShowOfTypeByUser(); userMenu(user); break; case "3": admin.showAllOrderByUser(user); userMenu(user); break; case "4": admin.changePwdByUser(user); userMenu(user); break; case "5": admin.showByUser(user); userMenu(user); break; case "6": System.out.println("谢谢使用，再见！"); System.exit(0); default: System.out.println("输入错误，请重新输入："); userMenu(user); } } public void adminMenu() { System.out.println("=========欢迎您尊贵的管理员======="); System.out.println("====【1】添加菜品==============="); System.out.println("====【2】查看所有菜品信息显示======="); System.out.println("====【3】查看指定类别的菜品信息====="); System.out.println("====【4】根据菜品id修改菜品价格====="); System.out.println("====【5】删除指定id的菜品========="); System.out.println("====【6】添加客户================"); System.out.println("====【7】查看客户列表============="); System.out.println("====【8】删除指定id的用户=========="); System.out.println("====【9】订单列表显示============="); System.out.println("====【10】根据订单id修改订单状态===="); System.out.println("====【11】退出================="); String m = sc.next(); switch (m) { case "1": admin.addDishes(); adminMenu(); break; case "2": System.out.println("请输入您需要每行显示多少数据："); int pageSize = sc.nextInt(); admin.showAllDishes(pageSize); adminMenu(); break; case "3": admin.selecBytypeOfAdmin(); adminMenu(); break; case "4": admin.selectByDishesID(); adminMenu(); break; case "5": admin.deleteDishes(); adminMenu(); break; case "6": admin.addUser(); adminMenu(); break; case "7": admin.findUser(); adminMenu(); break; case "8": admin.deleteUserByAdmin(); adminMenu(); break; case "9": admin.showAllOrder(); adminMenu(); break; case "10": admin.changeOrderValue(); adminMenu(); break; case "11": System.out.println("谢谢使用，再见！"); System.exit(0); break; default: System.out.println("输入错误，请重新输入："); adminMenu(); } }}

这里switch采取String（jdk1.7以后才支持）可以让用户就算输入错误也不会报错导致程序运行终止，又要重新输入（我摊牌了，就是懒）。

四、测试类

package com.softeem.lesson23.test2;public class Test { public static void main(String[] args) { Menu m = new Menu(); m.showMenu(); }}

五、实现部分界面截图

以上就是全部代码。