【Java学习笔记】72 - 满汉楼 - 餐饮管理系统

项目代码

https://github.com/yinhai1114/Java_Learning_Code/tree/main/IDEA_Chapter26

一、需求说明

满汉楼项目功能多，界面复杂，涉及到复杂的awt和swing技术和事件编程，做如下调整: 

1.去掉界面和事件处理(工作中使用很少)，使用控制台界面

2.完成满汉楼项目的登录、订座、点餐和结账、查看账单等功能.

3.在实际工作中，独立完成项目新功能非常重要，这是锻炼编程能力和思想的重要途径

1.用户登录

2.显示餐桌的状态

3.预定

4.显示菜品

5.点餐

6.查看账单

7.结账

 二、项目设计

三、功能实现

1.显示主菜单、二级菜单和退出系统功能

public void mainMenu(){while (loop){System.out.println("==============满汉楼===============");System.out.println("\t\t1.登录满汉楼");System.out.println("\t\t2.退出满汉楼");System.out.println("请输入你的选择");key = Utility.readString(1);switch (key){case "1":System.out.println("输入员工号:");String id = Utility.readString(50);System.out.println("输入密 码");String pwd = Utility.readString(50);//到数据库去判断if("123".equals(pwd)){System.out.println("===========登录成功===========");while(loop){System.out.println("=========满汉楼(二级菜单)==========");System.out.println("\t\t1 显示餐桌状态");System.out.println("\t\t2 预定餐桌状态");System.out.println("\t\t3 显示所有菜品");System.out.println("\t\t4 点餐服务");System.out.println("\t\t5 查看账单");System.out.println("\t\t6 结账");System.out.println("\t\t9 退出满汉楼");key = Utility.readString(1);switch (key){case "1":System.out.println("显示餐桌状态");break;case "2":System.out.println("预定餐桌");break;case "3":System.out.println("显示所有菜品");break;case "4":System.out.println("点餐服务");break;case "5":System.out.println("查看账单");break;case "6":System.out.println("结账");break;case "9":loop = false;break;default:System.out.println("你的输入有误 请重新输入");}}}else{System.out.println("===========登录失败===========");}break;case "2":System.out.println("2.退出满汉楼");loop = false;break;default:System.out.println("输入错误错误");}}System.out.println("退出满汉楼");}

2.用户登录

CREATE DATABASE mhl
#用户表
CREATE TABLE employee (id INT PRIMARY KEY AUTO_INCREMENT, #自增empId VARCHAR(50) UNIQUE NOT NULL DEFAULT '',#员工号pwd CHAR(32) NOT NULL DEFAULT '',#密码md5NAME VARCHAR(50) NOT NULL DEFAULT '',#姓名job VARCHAR(50) NOT NULL DEFAULT '' #岗位
)CHARSET=utf8; DROP TABLE employee
#添加测试数据
INSERT INTO employee VALUES(NULL, '6668612', MD5('123456'), '张三丰', '经理');
INSERT INTO employee VALUES(NULL, '6668622', MD5('123456'),'小龙女', '服务员');
INSERT INTO employee VALUES(NULL, '6668633', MD5('123456'), '张无忌', '收银员');
INSERT INTO employee VALUES(NULL, '666666', MD5('123456'), '老韩', '经理');
SELECT * FROM employee

/*** @author 银小海* @version 1.0* @email [e-mail]* 该类调用EmployeeDAO对象完成对表的各种操作*/
public class EmployeeService {//定义一个EmployeeDAO属性private EmployeeDAO employeeDAO = new EmployeeDAO();//方法 根据empId和pwd返回一个Employee对象public Employee getEmployeeByIdAndPwd(String empId,String pwd){return employeeDAO.querySingle("select * from employee where empId=? and pwd=md5(?)", Employee.class, empId, pwd);}
}

 该服务并不直接修改数据库，而是通过DAO调用JDBCDruid修改数据库

             if(employee != null){System.out.println("===========登录成功(" + employee.getName() + ")===========");while(loop){

3.显示餐桌状态 

1.创建新的餐位表

2.domain里设计一个类对应该表

3.DAO类对表crud

4.service调用DAO修改

-- 创建diningTable 表(id, state , orderName, orderTel ....)CREATE TABLE diningTable (id INT PRIMARY KEY AUTO_INCREMENT, #自增, 表示餐桌编号state VARCHAR(20) NOT NULL DEFAULT '',#餐桌的状态orderName VARCHAR(50) NOT NULL DEFAULT '',#预订人的名字orderTel VARCHAR(20) NOT NULL DEFAULT ''
)CHARSET=utf8; 
#测试数据
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
SELECT * FROM diningTable

2.设计一个类对应 该表 

/*** @author 银小海* @version 1.0* @email [e-mail]* 一个javabean 和diningTable表对应* 	id INT PRIMARY KEY AUTO_INCREMENT, #自增, 表示餐桌编号* 	state VARCHAR(20) NOT NULL DEFAULT '',#餐桌的状态* 	orderName VARCHAR(50) NOT NULL DEFAULT '',#预订人的名字* 	orderTel VARCHAR(20) NOT NULL DEFAULT ''*/public class DiningTable {private Integer id;private String state;private String orderName;private String orderTel;public DiningTable() {}public DiningTable(Integer id, String state, String orderName, String orderTel) {this.id = id;this.state = state;this.orderName = orderName;this.orderTel = orderTel;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getState() {return state;}public void setState(String state) {this.state = state;}public String getOrderName() {return orderName;}public void setOrderName(String orderName) {this.orderName = orderName;}public String getOrderTel() {return orderTel;}public void setOrderTel(String orderTel) {this.orderTel = orderTel;}@Overridepublic String toString() {return id + "\t\t\t" + state;}
}

4.

public class DiningTableService {//定义一个DiningTableDAO对象private DiningTableDAO diningTableDAO = new DiningTableDAO();//返回所有餐桌的信息public List<DiningTable> list(){return diningTableDAO.queryMulti("select id,state from diningTable", DiningTable.class);}
}

4.订座

功能说明如果该餐桌处于已经预定或者就餐状态，给出提示

1.在DiningTableService内添加对应方法

//根据id 查询对应的DiningTable对象 如果返回null 表示id编号对应餐桌不存在public DiningTable getDiningTableById(int id){//把sql语句放到查询分析器去测试一下return diningTableDAO.querySingle("select * from diningTable where id = ?",DiningTable.class,id);}//如果餐桌可以预定 调用方法对其状态进行更新public boolean orderDiningTable(int id,String orderName,String orderTel) {int dml =diningTableDAO.dml("update diningTable set state = '已经" +"预定',orderName = ?,orderTel=? where id = ?", orderName, orderTel, id);return dml > 0;}

 2.在view内添加判断用户输入方法，并在对应阶段调用该方法即可

//预定餐桌public void orderDiningTable(){System.out.println("=========预定餐桌==========");System.out.println("请选择要预定的餐桌的编号(-1退出)");int orderId = Utility.readInt();if(orderId == -1){return;}DiningTable diningTable = diningTableService.getDiningTableById(orderId);if(diningTable == null){ //说明不存在System.out.println("==========该餐桌不存在=========");return;}char key = Utility.readConfirmSelection();//输入Y/Nif (key == 'Y'){//要预定就调用方法 如果为null该对象不存在if(!("空".equals(diningTable.getState()))){System.out.println("==========该餐桌已被预定或就餐中=========");return;}System.out.println("预订人的名字:");String orderName = Utility.readString(50);System.out.println("预订人的电话:");String orderTel = Utility.readString(50);if(diningTableService.orderDiningTable(orderId,orderName,orderTel)){System.out.println("预定餐桌成功");}else{System.out.println("预定餐桌失败");}//过关斩将}else{System.out.println("=========取消预定餐桌==========");}}

5.显示菜品

1.需要创建一个新的菜单表

2.需要在java内建立domain类

3.需要创建菜单的DAO类

4.需要service组织sql并调用DAO

-- 创建menu表(id, name, type, price)
#菜谱
CREATE TABLE menu (id INT PRIMARY KEY AUTO_INCREMENT, #自增主键，作为菜谱编号(唯一)NAME VARCHAR(50) NOT NULL DEFAULT '',#菜品名称TYPE VARCHAR(50) NOT NULL DEFAULT '', #菜品种类price DOUBLE NOT NULL DEFAULT 0#价格
)CHARSET=utf8; 
#测试数据
INSERT INTO menu VALUES(NULL, '八宝饭', '主食', 10);
INSERT INTO menu VALUES(NULL, '叉烧包', '主食', 20);
INSERT INTO menu VALUES(NULL, '宫保鸡丁', '热菜', 30);
INSERT INTO menu VALUES(NULL, '山药拨鱼', '凉菜', 14);
INSERT INTO menu VALUES(NULL, '银丝卷', '甜食', 9);
INSERT INTO menu VALUES(NULL, '水煮鱼', '热菜', 26);
INSERT INTO menu VALUES(NULL, '甲鱼汤', '汤类', 100);
INSERT INTO menu VALUES(NULL, '鸡蛋汤', '汤类', 16);

2.在java内创建domain的Menu类 对应表的对象

/*** @author 银小海* @version 1.0* @email [e-mail]* 该javabean和 menu 表对应*  id INT PRIMARY KEY AUTO_INCREMENT, #自增, 表示餐桌编号* 	state VARCHAR(20) NOT NULL DEFAULT '',#餐桌的状态* 	orderName VARCHAR(50) NOT NULL DEFAULT '',#预订人的名字* 	orderTel VARCHAR(20) NOT NULL DEFAULT ''*/
public class Menu {private Integer id;private String name;private String type;private Double price;public Menu(){//无参构造器}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getType() {return type;}public void setType(String type) {this.type = type;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}public Menu(Integer id, String name, String type, Double price) {this.id = id;this.name = name;this.type = type;this.price = price;}
}

3.DAO继承BasicDAO

4.service类 组织sql调用DAO

public class MenuService {private MenuDAO menuDAO = new MenuDAO();//返回所有的菜品public List<Menu> list(){return menuDAO.queryMulti("select * from menu",Menu.class);}}

在view内编写方法调用service类的方法

public void listMenu(){List<Menu> list = menuService.list();System.out.println("\n菜品编号\t\t菜品名\t\t类别\t\t价格");for (Menu menu : list) {System.out.println(menu);}System.out.println("=========显示完毕==========");
}

6.点餐

功能说明要求对餐桌号，菜品编号，做合理性校验，如果不合理，给出提示信息

餐桌号 菜品号 检验是否合理，点餐成功，需要修改餐桌状态，生成账单

1.需要创建一个新的账单表

2.需要在java内建立domain类

3.需要创建菜单的DAO类

4.需要service组织sql并调用DAO

1.新建账单表

#增加表 bill 账单表(id, billId, menuId, nums, billDate, money, state, diningTableId )
#账单流水, 考虑可以分开结账, 并考虑将来分别统计各个不同菜品的销售情况
CREATE TABLE bill (id INT PRIMARY KEY AUTO_INCREMENT, #自增主键billId VARCHAR(50) NOT NULL DEFAULT '',#账单号可以按照自己规则生成 UUIDmenuId INT NOT NULL DEFAULT 0,#菜品的编号, 也可以使用外键nums INT NOT NULL DEFAULT 0,#份数money DOUBLE NOT NULL DEFAULT 0, #金额diningTableId INT NOT NULL DEFAULT 0, #餐桌billDate DATETIME NOT NULL ,#订单日期state VARCHAR(50) NOT NULL DEFAULT '' # 状态 '未结账' , '已经结账', '挂单','现金','支付宝','坏账'
)CHARSET=utf8;SELECT * FROM bill;

2.创建domain类 javabean

/*** @author 银小海* @version 1.0* @email [e-mail]* 	id INT PRIMARY KEY AUTO_INCREMENT, #自增主键* 	billId VARCHAR(50) NOT NULL DEFAULT '',#账单号可以按照自己规则生成 UUID* 	menuId INT NOT NULL DEFAULT 0,#菜品的编号, 也可以使用外键* 	nums INT NOT NULL DEFAULT 0,#份数* 	money DOUBLE NOT NULL DEFAULT 0, #金额* 	diningTableId INT NOT NULL DEFAULT 0, #餐桌* 	billDate DATETIME NOT NULL ,#订单日期* 	state VARCHAR(50) NOT NULL DEFAULT '' # 状态 '未结账' , '已经结账', '挂单','现*/
public class Bill {private Integer id;private String billId;private Integer menuId;private Integer nums;private Double money;private Integer diningTableId;private Date billDate;private String state;public Bill() {}public Bill(Integer id, String billId, Integer menuId, Integer nums, Double money, Integer diningTableId, Date billDate, String state) {this.id = id;this.billId = billId;this.menuId = menuId;this.nums = nums;this.money = money;this.diningTableId = diningTableId;this.billDate = billDate;this.state = state;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBillId() {return billId;}public void setBillId(String billId) {this.billId = billId;}public Integer getMenuId() {return menuId;}public void setMenuId(Integer menuId) {this.menuId = menuId;}public Integer getNums() {return nums;}public void setNums(Integer nums) {this.nums = nums;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningTableId() {return diningTableId;}public void setDiningTableId(Integer diningTableId) {this.diningTableId = diningTableId;}public Date getBillDate() {return billDate;}public void setBillDate(Date billDate) {this.billDate = billDate;}public String getState() {return state;}public void setState(String state) {this.state = state;}@Overridepublic String toString() {return  id +"\t\t" + menuId +"\t\t\t" + nums +"\t\t\t" + money +"\t" + diningTableId +"\t\t" + billDate +"\t\t" + state ;}
}

3.编写账单服务类 该方法还需要其他服务类辅助 因此也需要再其他服务类内增加方法

public class BillService {//定义BillDAO属性private BillDAO billDAO = new BillDAO();//需要定义另一个service获得菜单用来计算金额private MenuService menuService = new MenuService();//需要定义另一个service更改餐桌的状态private DiningTableService diningTableService = new DiningTableService();//编写点餐的方法//1.生成账单 2. 需要更新对应餐桌状态 3.如果成功返回true 否则返回falsepublic boolean orderMenu(int menuId,int nums,int diningTableId){//生成一个账单号UUIDString billUUID = UUID.randomUUID().toString();//将这个账单生成到bill表 要直接计算账单的金额 也就是获得menu对象int dml = billDAO.dml("insert into bill values" +"(null,?,?,?,?,?,now(),'未结账')", billUUID, menuId, nums, menuService.getMenuId(menuId).getPrice() * nums, diningTableId);if(dml <= 0){return false;}//需要更新餐桌状态return diningTableService.updateDiningTableState(diningTableId,"就餐中");}
}

4.在view调用该服务类

 //完成点餐public void orderMenu() {System.out.println("==============点餐服务============");System.out.print("请输入点餐的桌号(-1退出): ");int orderDiningTableId = Utility.readInt();if (orderDiningTableId == -1) {System.out.println("==============取消点餐============");return;}System.out.print("请输入点餐的菜品号(-1退出): ");int orderMenuId = Utility.readInt();if (orderMenuId == -1) {System.out.println("==============取消点餐============");return;}System.out.print("请输入点餐的菜品量(-1退出): ");int orderNums = Utility.readInt();if (orderNums == -1) {System.out.println("==============取消点餐============");return;}//验证餐桌号是否存在.DiningTable diningTable = diningTableService.getDiningTableById(orderDiningTableId);if (diningTable == null) {System.out.println("==============餐桌号不存在============");return;}//验证菜品编号Menu menu = menuService.getMenuId(orderMenuId);if (menu == null) {System.out.println("==============菜品号不存在============");return;}//点餐if (billService.orderMenu(orderMenuId, orderNums, orderDiningTableId)) {System.out.println("==============点餐成功============");} else {System.out.println("==============点餐失败============");}}

7.查看账单

1.billDao获得bill对象

2.service编写方法调用billDAO获得bill对象

3.view调用该service方法

2.service调用DAO获得list数组

public List<Bill> list(){return billDAO.queryMulti("select * from bill",Bill.class);}

3.view显示账单

public void listBill() {List<Bill> bills = billService.list();System.out.println("\n编号\t\t菜品号\t\t菜品量\t\t金额\t\t桌号\t\t日期\t\t\t\t\t\t\t状态");for (Bill bill : bills) {System.out.println(bill);}System.out.println("==============显示完毕============");}

 8.结账

(1)对餐桌号进行校验        (2)修改bill表的state        (3)修改diningTable信息        (4)不需要增加表和类

1.在 service类内查看是否有未结账 或者餐桌是否存在 （校验）

//查看某个产值是否有未结账的账单public boolean hasPayBillByDiningTableId(int diningTableId) {Bill bill =billDAO.querySingle("SELECT * FROM bill WHERE diningTableId=? AND state = '未结账' LIMIT 0, 1", Bill.class, diningTableId);return bill != null;}//完成结账[如果餐桌存在，并且该餐桌有未结账的账单]//如果成功，返回true, 失败返回 falsepublic boolean payBill(int diningTableId, String payMode) {//如果这里使用事务的话，需要用ThreadLocal来解决 , 框架中比如mybatis 提供了事务支持//1. 修改bill表int update = billDAO.dml("update bill set state=? where diningTableId=? and state='未结账'", payMode, diningTableId);if(update <= 0) { //如果更新没有成功，则表示失败...return false;}//2. 修改diningTable表//注意：不要直接在这里操作，而应该调用DiningTableService 方法,完成更新，体现各司其职if(!diningTableService.updateDiningTableToFree(diningTableId, "空")) {return false;}return true;}

2.修改diningTable为空闲

//需要提供一个更新餐桌状态为空闲的方法public boolean updateDiningTableToFree(int id,String state){int dml = diningTableDAO.dml("update diningTable set state=?,orderName = '',orderTel = '' where id=?", state, id);return dml > 0;}

 3.在view内定义方法调用service方法

//完成结账public void payBill() {System.out.println("==============结账服务============");System.out.print("请选择要结账的餐桌编号(-1退出): ");int diningTableId = Utility.readInt();if (diningTableId == -1) {System.out.println("=============取消结账============");return;}//验证餐桌是否存在DiningTable diningTable = diningTableService.getDiningTableById(diningTableId);if (diningTable == null) {System.out.println("=============结账的餐桌不存在============");return;}//验证餐桌是否有需要结账的账单if (!billService.hasPayBillByDiningTableId(diningTableId)) {System.out.println("=============该餐位没有未结账账单============");return;}System.out.print("结账方式(现金/支付宝/微信)回车表示退出: ");String payMode = Utility.readString(20, "");//说明如果回车，就是返回 ""if ("".equals(payMode)) {System.out.println("=============取消结账============");return;}char key = Utility.readConfirmSelection();if (key == 'Y') { //结账//调用我们写的方法if (billService.payBill(diningTableId, payMode)) {System.out.println("=============完成结账============");} else {System.out.println("=============结账失败============");}} else {System.out.println("=============取消结账============");}}

四、进行代码拓展 

1.多表查询的需求

我们可以再增加一个MultableBean，跟多张表进行映射，所以要有一个MultableBeanDAO，然后调用该DAO

另一个方案

DBUtils数据库连接池多表连接查询_利用数据池连接数据库多个表-CSDN博客

1.创建bean表

public class MultiTableBean {private Integer id;private String billId;private Integer menuId;private Integer nums;private Double money;private Integer diningTableId;private Date billDate;private String state;//增加一个来自menu表的列 name//思考 这里的属性名是否一定要和表的列名保持一致.//答: 可以不一致，但是需要sql做相应的修改, 规范需要保持一致.private String name;//增加来自menu表的列 priceprivate Double price;//默认值 nulllpublic MultiTableBean() {System.out.println("反射调用....");}//    public MultiTableBean(Integer id, String billId, Integer menuId, Integer nums, Double money, Integer diningTableId, Date billDate, String state, String name, Double price) {
//        this.id = id;
//        this.billId = billId;
//        this.menuId = menuId;
//        this.nums = nums;
//        this.money = money;
//        this.diningTableId = diningTableId;
//        this.billDate = billDate;
//        this.state = state;
//        this.name = name;
//        this.price = price;
//    }//给price生成setter 和 getterpublic Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}//给name生成setter 和 getterpublic String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBillId() {return billId;}public void setBillId(String billId) {this.billId = billId;}public Integer getMenuId() {return menuId;}public void setMenuId(Integer menuId) {this.menuId = menuId;}public Integer getNums() {return nums;}public void setNums(Integer nums) {this.nums = nums;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningTableId() {return diningTableId;}public void setDiningTableId(Integer diningTableId) {this.diningTableId = diningTableId;}public Date getBillDate() {return billDate;}public void setBillDate(Date billDate) {this.billDate = billDate;}public String getState() {return state;}public void setState(String state) {this.state = state;}@Overridepublic String toString() {return  id +"\t\t" + menuId +"\t\t\t" + nums +"\t\t\t" + money +"\t" + diningTableId +"\t\t" + billDate +"\t\t" + state +"\t\t" + name +"\t\t" + price;}
}

2.创建dao类

3. view中调用

 public void listBill() {/*//单表查询List<Bill> bills = billService.list();System.out.println("\n编号\t\t菜品号\t\t菜品量\t\t金额\t\t桌号\t\t日期\t\t\t\t\t\t\t状态");for (Bill bill : bills) {System.out.println(bill);}System.out.println("==============显示完毕============");*///多表查询List<MultiTableBean> multiTableBeans = billService.list2();System.out.println("\n编号\t\t菜品号\t\t菜品量\t\t金额\t\t桌号\t\t日期\t\t\t\t\t\t\t状态\t\t菜品名\t\t价格");for (MultiTableBean bill : multiTableBeans) {System.out.println(bill);}System.out.println("==============显示完毕============");}

 根据需要增加需要的字段

当将来的多表查询次数越来越多可以考虑拆分

2.javaBean和表的参数名一致性的问题

//增加一个来自menu表的列 name

//思考 这里的属性名是否一定要和表的列名保持一致.

//答: 可以不一致，但是需要sql做相应的修改（例如 name as name2）, 规范需要保持一致.

3.对于员工多字段的设置

4.完成更多功能 

可以完成登录管理和人事管理