一：需求

1.完成一个酒店后台管理系统，当然只是模拟，在控制台就行模拟
2.实现管理人员的登录和酒店成本账单的查看，以及正常的点餐，结账和查看账单等等功能

二：实现的功能展示

1.用户登录（这里输入的员工号和密码要与数据库中存的进行校验）

2.显示前台和后台成本信息

3：前台

4：后台

其他细节功能展示不展示了

三：分层实现

1.图示

2：代码分析

1>:总体上先将框架写好，然后在补充功能
2>.具体的功能我们是从下往上开始写，因为上方的逻辑结构可能用到下方的
3>:我们补充的功能先创建一个表，然后创建一个Javabean（将你想要获取的表当中的字段，写成类的属性，注意空构造器和set,get方法）,然后就是创建一个相关类的DAO,方便我们sql语句的操作，再然后就是Service层这是我们的业务层，我们把我们想要实现的功能在这里封装成方法，提供给最后的View层调用,从这里实现的功能的步骤我们可以看出，这是一个自下向上的过程，

3：代码层次分析

1>:德鲁伊连接池+DBUtils+DAO+Mysql
2>:我们首先要引入相关的jar包（druid.jar;dbu.jar,mysql.jar）
3>:德鲁伊连接池我们需要相关的配置文件，url=(数据库的地址)，password,username,
初始化可以连接多少连接，最多可以有多少连接，指的是java程序连接数据库,使用连接池，我们可以提高我们的连接效率，还有一个连接池是c3p0这个连接池比德鲁伊要慢一些，所以我们采用的是德鲁伊连接池.
4>:
关于DBUtils,这是通过select得到的那个结果只能在不关闭连接的时候可以看见，一旦关闭了连接，我们就无法获得查询的结果，然后就用到了Javbean(创建一个类包含其表的属性)，通过反射获取到相关的属性，然后放到一个容器当中，这样你关闭了连接，但查询的结果还是可以看到的

5>:
DAO的引出是因为我们频繁的操作sql语句，每次都要写来连接，写sql,发送sql,返回sql语句，这其实是很麻烦的，所以BasicDAO做了一件事，将select和dml操作封装起来，用的时候传入相关的类和sql语句以及想要的操作赋的值。

四：代码+创建的表

1.注意引进的jar包，

其分的包也就是上诉的层次结构

2：view包

package com.wyj.mhl.view;import com.wyj.mhl.domain.Employee;
import com.wyj.mhl.domain.Menu;
import com.wyj.mhl.domain.diningTable;
import com.wyj.mhl.service.*;
import com.wyj.mhl.utils.Utility;public class MHL_View {public static void main(String[] args) {new MHL_View().mainMenu();}//预定餐桌public void reser_food(){System.out.print("请选择要预定的餐桌编号(1到6号餐桌)(-1退出):");int idd = Utility.readInt();if (idd != -1) {System.out.print("请确认是否要预定(Y/N):");char ch = Utility.readChar();if (ch == 'Y') {System.out.print("请输入预定人的名字:");String name = Utility.readString(10);System.out.print("请输入预定人的电话:");String phone = Utility.readString(10);int i = diningTableService.book_table(idd, name, phone);if(i!= 0){System.out.println("======预定成功======");}else{return;}} else {return;}} else {return ;}}//点餐public void OrderMenu() {System.out.print("请输入点餐的桌号(-1退出):");int idd2 = Utility.readInt();if (idd2 == -1)return;diningTable empty = diningTableService.isEmpty(idd2);if (!empty.getState().equals("空")) {System.out.println("===您选的座位已占==");return;}System.out.print("选择菜品的编号(-1退出):");int menu_id1 = Utility.readInt();if (menu_id1 == -1)return;Menu singleBYid = menuService.getBillSingleBYid(menu_id1);if (singleBYid == null) {System.out.println("====您输入的菜品单号本店没有===");return;}System.out.print("选择菜品的数量(-1退出):");int menu_nums = Utility.readInt();if (menu_nums == -1)return;System.out.print("确认是否点这个菜(Y?N):");char ch = Utility.readChar();if (ch == 'Y') {if (billService.orderMenu(menu_id1, menu_nums, idd2)) {System.out.println("=====点餐成功=====");} else {System.out.println("====点餐失败");}} else {System.out.println("==请重新输入Y/N====");return;}}//结账public void leave(){System.out.print("请选择要结账的餐桌编号(-1退出):");int leave_id = Utility.readInt();if(leave_id == -1){return ;}//检验餐桌号是否存在diningTable empty = diningTableService.isEmpty(leave_id);if(empty == null || empty.getState().equals("空")){if(empty == null)System.out.println("===您结账的餐桌本店不存在===");elseSystem.out.println("===您并未在该餐桌就餐===");return;}//检验结账的餐桌是否为空System.out.print("结账方式(现金/支付宝/微信):");String leave_way = Utility.readString(10,"");if("".equals(leave_way)){System.out.println("===取消结账===");return;}System.out.print("确认是否结账(Y/N):");char ch = Utility.readChar();if( ch == 'Y'){if (billService.invoicing(leave_id,leave_way)){System.out.println("====结账成功====");}else{System.out.println("====结账失败====");}}else{System.out.println("===请您结账离开本店===");return;}}private boolean loop = true;private String key = "";//一级菜单private String option = "";//二级菜单private EmployeeService service = new EmployeeService();//员工登录的业务private DiningTableService diningTableService = new DiningTableService();//点餐的业务层private MenuService menuService = new MenuService();//显示菜单private BillService billService = new BillService();//账单private MulityTableService mulityTableService = new MulityTableService();//这个可以显示账单中带菜名private CostSerivice costSerivice = new CostSerivice();//显示成本信息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.print("亲输入您的选项：");key = Utility.readString(1);switch (key) {case "1":System.out.print("请输入员工号:");String empId = Utility.readString(20);System.out.print("请输入  密码:");String pwd = Utility.readString(20);Employee employee = service.getEmployeeEmpidandpwd(empId, pwd);if (employee != null) {System.out.println("===========登录成功==========");System.out.println(employee.getEmpId() + " " + employee.getName());while(loop) {System.out.println("===满汉楼的功能表===");System.out.println("1.前台状态");System.out.println("2.后台成本");System.out.println("3.退出系统");System.out.print("请选择您的选项：");int option2 = Utility.readInt();switch (option2) {case 1://显示二级菜单while (loop) {System.out.println("===========满汉楼二级菜单==========");System.out.println("\t\t1.显示餐桌的状态");System.out.println("\t\t2.预定餐桌");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\t7.退出满汉楼");System.out.print("请输入您的选项:");option = Utility.readString(1);switch (option) {case "1":diningTableService.showDiningTable();//显示餐桌的状态break;case "2":System.out.println("========预定餐桌========");new MHL_View().reser_food();break;case "3":System.out.println("======显示菜单======");menuService.showMenu();break;case "4":System.out.println("======点餐服务======");new MHL_View().OrderMenu();break;case "5":System.out.println("===查看账单====");//billService.showBill();mulityTableService.ShowBillandMenu();break;case "6":System.out.println("====结账====");new MHL_View().leave();break;case "7":loop = false;break;default:System.out.println("输入没有在选项范围内");}}break;case 2:System.out.println("====成本控制====");costSerivice.showCost();break;case 3:loop = false;break;default:System.out.println("您的输入有误，请重新输入");}}} else {System.out.println("===========登录失败==========");}break;case "2":loop = false;break;default:System.out.println("输入的有问题，请重新输入");}}System.out.println("退出满汉楼!");}}

3：utiles包中有一个输入的的类和一个将德鲁伊连接池变成工具类

(1):Utility

package com.wyj.mhl.utils;import java.util.Scanner;public class Utility {private static Scanner scanner;static {scanner = new Scanner(System.in);}public Utility() {}public static char readMenuSelection() {while (true) {String str = readKeyBoard(1, false);char c = str.charAt(0);if (c == 1 || c == 2 || c == 3 || c == 4 || c == 5) {return c;}System.out.print("选择错误，请重新输入：");}}public static char readChar() {String str = readKeyBoard(1, false);return str.charAt(0);}public static char readChar(char defaultValue){String str=readKeyBoard(1, true);return str.length()==0?defaultValue:str.charAt(0);}public static int readInt(){while (true){String str=readKeyBoard(2, false);try {int n=Integer.parseInt(str);return n;}catch (NumberFormatException var3){System.out.println("数字输入错误，请重新输入：");}}}public static int readInt(int defaultValue) {while(true) {String str = readKeyBoard(2, true);if (str.equals("")) {return defaultValue;}try {int n = Integer.parseInt(str);return n;} catch (NumberFormatException var4) {System.out.print("数字输入错误，请重新输入：");}}}public static String readString(int limit) {return readKeyBoard(limit, false);}public static String readString(int limit, String defaultValue) {String str = readKeyBoard(limit, true);return str.equals("") ? defaultValue : str;}public static char readConfirmSelection(){while (true){String str=readKeyBoard(1,false).toUpperCase();char c=str.charAt(0);if(c=='Y'||c=='N'){return c;}System.out.print("选择错误，请重新输入：");}}private static String readKeyBoard(int limit, boolean blankReturn){String line="";while (scanner.hasNextLine()){line=scanner.nextLine();if(line.length()==0){if(blankReturn){return line;}}else {if(line.length()>=1 && line.length()<=limit){break;}System.out.println("输入长度（不大于" + limit + "）错误，请重新输入：");}}return line;}
}

(2):JDBCUtilsBYDruid

package com.wyj.mhl.utils;import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;public class JDBCUtilsBYDruid {//(1):定义一个数据源,作为连接池private static DataSource ds;//(2):静态代码块  类加载的时候自动加载 而且只加载一次static {//获取配置文件的信息Properties properties = new Properties();try {properties.load(new FileInputStream("src//druid.properties"));ds = DruidDataSourceFactory.createDataSource(properties);} catch (Exception e) {e.printStackTrace();}}//设置成静态的方法可以直接用类名进行调用public static Connection getConnection() throws SQLException {return ds.getConnection();}//关闭连接，是关闭java程序与连接池的连接 而并不是关闭与数据库的连接public static void close(ResultSet set, Statement statement,Connection connection){try {if(set != null){set.close();}if(statement != null){statement.close();}if(connection != null){connection.close();}} catch (SQLException e) {e.printStackTrace();}}}

4.Service包

(1):BillService

package com.wyj.mhl.service;import com.wyj.mhl.dao.BillDAO;
import com.wyj.mhl.domain.Bill;import java.util.List;
import java.util.UUID;public class BillService {private BillDAO billDAO = new BillDAO();private MenuService menuService = new MenuService();private DiningTableService diningTableService = new DiningTableService();/*** 实现点餐的功能：* 1.点菜品单号是否存在，点的餐桌号是否存在， 在view层中实现* 2.id:自增 不用管他* ,biilid：随机字符串 不用管他* ,menuid：输入的菜品号 形参* ,nums：点单数量 形参* ,money：计算出来的，需要MenuService 提供方法获取菜品的价格* ,state：自己输入的* billdate：当前直接获取* diningTable：输入的餐桌号，形参*/public boolean orderMenu(int menuid,int nums,int dingtableid){String billid = (UUID.randomUUID().toString());//生成一个随机账单号billid = billid.substring(30);int i = billDAO.update("insert into bill values(null,?,?,?,?,?,now(),?)",billid, menuid, nums, menuService.getBillSingleBYid(menuid).getPrice() * nums, "未结账",  dingtableid);if(i < 0){return false;}//更新餐桌的状态return diningTableService.updatestate(dingtableid,"就餐中");}//显示账单public void showBill(){List<Bill> list = billDAO.queryMulti("select * from bill", Bill.class);for (Bill bill : list) {System.out.println(bill);}}/*** 结账：* 1.输入餐桌号（检验餐桌是否存在，检验餐桌是否为空（为空的话 不用结账））* 2.输入结账方式 支付宝，现金，微信* 3.更新餐桌的状态** 就餐号	账单单号		菜单号	点餐的份数	金额		餐桌状态		餐桌号*/public boolean invoicing(int id,String check_way){int i = billDAO.update("update bill set state = ? where diningTable = ?", check_way, id);if(i < 0){return false;}//更新餐桌的状态return diningTableService.updatestate(id,"空");}}

(2):CostService

package com.wyj.mhl.service;import com.wyj.mhl.dao.CostDAO;
import com.wyj.mhl.domain.Cost;import java.util.List;public class CostSerivice {private CostDAO costDAO = new CostDAO();//显示成本：public void showCost(){List<Cost> list = costDAO.queryMulti("select * from cost", Cost.class);System.out.println("日期"+"\t\t"+"电费"+"\t\t"+"水费"+"\t\t"+"人工费"+"\t\t"+"食品费");for (Cost cost : list) {System.out.println(cost);}}}

(3)DingtableService

package com.wyj.mhl.service;import com.wyj.mhl.dao.DingTableDAO;
import com.wyj.mhl.domain.diningTable;import java.util.List;/*** 业务层：提供方法显示餐桌的状态**/
public class DiningTableService {private  DingTableDAO dingTableDAO = new DingTableDAO();//1.显示餐桌的状态public void showDiningTable(){List<diningTable> list = dingTableDAO.queryMulti("select * from diningTable",diningTable.class );System.out.println("餐桌编号"+"\t\t"+"餐桌状态");for (diningTable diningTable : list) {System.out.println(diningTable);}}//2.预定餐桌/*** 功能：* 请选择要预定餐桌编号(-1退出):* 预定人名字:* 预定人电话:* 确认是否预定(Y/N):** 注意的问题:* 1.输入的餐桌编号是否存在的编号* 2.餐桌是否被预定*/public int  book_table(int idd,String name,String phone){int update;//查询要预定餐桌的状态（看是否被预定）Object scalar = dingTableDAO.queryScalar("select state from diningTable where id = ?", idd);//查看是否存在diningTable table = dingTableDAO.querySingle("select * from diningTable where id = ?", diningTable.class, idd);if(table == null ){System.out.println("====输入的idd号不存在,请重新输入====");update = 0;return update;}else if(scalar.equals("已预定")){update = 0;System.out.println("====进预定的餐桌号已经被预定了，请重新选择！====");return update;}else {update = dingTableDAO.update("update diningTable " +"set state = ? ,orderName = ?,orderTel = ? " +"where id = ?", "已预定", name, phone, idd);}return update;}//为billservice提供更新状态的方法public boolean updatestate(int id,String state){int i = dingTableDAO.update("update diningTable set state = ? where id = ?", state, id);if(i < 0)return false;return true;}//显示判断餐桌是否为存在public diningTable isEmpty(int id){diningTable table = dingTableDAO.querySingle("select * from diningTable where id = ?", diningTable.class, id);return  table;}}

(4):EmployeeService

package com.wyj.mhl.service;import com.wyj.mhl.dao.EmployeeDAO;
import com.wyj.mhl.domain.Employee;import java.util.List;/*** 业务层:这里通过调用EmployeeDAO来完成相关的操作*/public class EmployeeService {public static void main(String[] args) {EmployeeDAO employeeDAO = new EmployeeDAO();List<Employee> list = employeeDAO.queryMulti("select * from employee", Employee.class);for (Employee employee : list) {System.out.println(employee);}}private  EmployeeDAO employeeDAO = new EmployeeDAO();/*** 我们在确定用户输入的账号密码是否正确的时候，并不是拿输入的数据去和数据库中的* 数据进行比较,而是将输入的数据在数据库寻找，看是否可以找到*///如果返回结果为空 就是没查到该数据public Employee getEmployeeEmpidandpwd(String empId,String pwd){Employee employee = employeeDAO.querySingle("select * from employee where empId = ? and pwd = md5(?)", Employee.class,empId,pwd);return employee;}}

(5):MenuService

package com.wyj.mhl.service;import com.wyj.mhl.dao.MenuDAO;
import com.wyj.mhl.domain.Bill;
import com.wyj.mhl.domain.Menu;import java.util.List;public class MenuService {public static void main(String[] args) {new MenuService().showMenu();}private MenuDAO menuDAO = new MenuDAO();//显示菜品public void showMenu(){List<Menu> list = menuDAO.queryMulti("select * from menu", Menu.class);for (Menu menu : list) {System.out.println(menu);}}//通过返回一个menu对象  菜单号来获取到一行的数据 来求取价格public Menu getBillSingleBYid(int menuid){Menu single = menuDAO.querySingle("select * from menu where id = ?", Menu.class, menuid);return single;}//提供方法 来判断这个菜品是否存在}

(6)MulitytableService(这是一个多表)

package com.wyj.mhl.service;import com.wyj.mhl.dao.MulityTableDAO;
import com.wyj.mhl.domain.Mulitytable;import java.util.List;public class MulityTableService {private MulityTableDAO mulityTableDAO = new MulityTableDAO();//显示账单和菜名public void ShowBillandMenu(){List<Mulitytable> list = mulityTableDAO.queryMulti("select bill.*,food_name,price from bill,menu " +" where bill.menuId = menu.id", Mulitytable.class);for (Mulitytable mulitytable : list) {System.out.println(mulitytable);}}}

5.domain(javabain)

(1):BIll

package com.wyj.mhl.domain;import com.sun.org.apache.bcel.internal.generic.IINC;/*** 生成账单：* id INT PRIMARY KEY AUTO_INCREMENT,-- 自增主键* billId VARCHAR(50) NOT NULL DEFAULT'', -- 账单号* menuId INT NOT NULL DEFAULT 0,-- 菜单编号* nums INT NOT NULL DEFAULT 0,-- 菜的份数* money DOUBLE NOT NULL DEFAULT 0,-- 花的钱* state VARCHAR(32) NOT NULL DEFAULT '', -- 餐桌的状态 结账，未结账，挂单，现金，支付宝* billdate DATETIME* diningTable INT NOT NULL DEFAULT 0;-- 餐桌号*/
public class Bill {private Integer id;//自增的主键private String billId;//账单号private Integer menuId;//菜单号private Integer nums;//点菜的份数private Double money;//点菜花的钱private String state;//餐桌的状态private Integer diningTable;//餐桌号public Bill() {} //空构造器，为后面的（BasicDAO）反射底层的调用做准备，public Bill(Integer id, String billId, Integer menuId, Integer nums, Double money, String state,Integer diningTable) {this.id = id;this.billId = billId;this.menuId = menuId;this.nums = nums;this.money = money;this.state = state;this.diningTable = diningTable;}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 String getState() {return state;}public void setState(String state) {this.state = state;}public Integer getDiningTable() {return diningTable;}public void setDiningTable(Integer diningTable) {this.diningTable = diningTable;}@Overridepublic String toString() {System.out.println("就餐号"+"\t"+"账单单号"+"\t\t"+"菜单号"+"\t"+"点餐的份数"+"\t"+"金额"+"\t\t"+"状态"+"\t\t"+"餐桌号");return id + "\t\t" + billId + "\t\t" + menuId + "\t\t" + nums + "\t\t\t" + money + "\t\t"+state + "\t\t"+diningTable+"\n";}
}

(2):Cost

package com.wyj.mhl.domain;/*** 成本表：* `date` VARCHAR(32) NOT NULL DEFAULT '',* 	electricity DOUBLE NOT NULL DEFAULT 0, -- 电费* 	water DOUBLE NOT NULL DEFAULT 0, -- 水费* 	people DOUBLE NOT NULL DEFAULT 0, -- 人工费* 	food DOUBLE NOT NULL DEFAULT 0 -- 食品费**/
public class Cost {private String date;private Double electricity;private Double water;private Double people;private Double food;public Cost(){}public Cost(String date, Double electricity, Double water, Double people, Double food) {this.date = date;this.electricity = electricity;this.water = water;this.people = people;this.food = food;}public String getDate() {return date;}public void setDate(String date) {this.date = date;}public Double getElectricity() {return electricity;}public void setElectricity(Double electricity) {this.electricity = electricity;}public Double getWater() {return water;}public void setWater(Double water) {this.water = water;}public Double getPeople() {return people;}public void setPeople(Double people) {this.people = people;}public Double getFood() {return food;}public void setFood(Double food) {this.food = food;}@Overridepublic String toString() {return date+"\t\t"+electricity+"\t\t"+water+"\t\t"+people+"\t\t"+food;}
}

(3):dingtable

package com.wyj.mhl.domain;/*** 创建餐桌表：显示餐桌状态*/public class diningTable {private Integer id;private String state;//餐桌状态private String orderName;//点餐人姓名private String orderTel;//点餐人电话public diningTable() {//反射底层要用到，在DAO层中需要用到反射来获取类的属性}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+"\n";}
}

(4)；Employee

package com.wyj.mhl.domain;/*** id INT  PRIMARY KEY AUTO_INCREMENT,* 	empId  VARCHAR(32) NOT NULL DEFAULT '', -- 员工号* 	pwd CHAR(32) NOT NULL DEFAULT '',-- 加密密码* 	`name` VARCHAR(32) NOT NULL DEFAULT '',-- 名字* 	job VARCHAR(20) NOT NULL DEFAULT '' -- 工作*/
public class Employee {private Integer id;private String empId;private String pwd;private String name;private String job;public Employee(){//无参构造器  底层apache-dbutils反射需要}public Employee(Integer id, String empId, String pwd, String name, String job) {this.id = id;this.empId = empId;this.pwd = pwd;this.name = name;this.job = job;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getEmpId() {return empId;}public void setEmpId(String empId) {this.empId = empId;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getJob() {return job;}public void setJob(String job) {this.job = job;}@Overridepublic String toString() {return "Employee{" +"id=" + id +", empId='" + empId + '\'' +", pwd='" + pwd + '\'' +", name='" + name + '\'' +", job='" + job + '\'' +'}'+ "\n";}
}

(5):Menu

package com.wyj.mhl.domain;/*** javabean：显示菜单*/
public class Menu {private Integer id;private String food_name;private String food_class;private Double price;public Menu() {}//空构造器，反射底层要调用，在BasicDAO中需要用到public Menu(Integer id, String food_name, String food_class, Double price) {this.id = id;this.food_name = food_name;this.food_class = food_class;this.price = price;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getFood_name() {return food_name;}public void setFood_name(String food_name) {this.food_name = food_name;}public String getFood_class() {return food_class;}public void setFood_class(String food_class) {this.food_class = food_class;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}@Overridepublic String toString() {return id + "\t" + food_name + "\t\t" + food_class + "\t\t" + price+"\n";}
}

(6):Mulitytable

package com.wyj.mhl.domain;public class Mulitytable {private Integer id;//自增的主键private String billId;//账单号private Integer menuId;//菜单号private Integer nums;//点菜的份数private Double money;//点菜花的钱private String state;//餐桌的状态private Integer diningTable;//餐桌号private String food_name;//菜名//增加每种菜的价格private Double price;public Mulitytable() {}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 String getState() {return state;}public void setState(String state) {this.state = state;}public Integer getDiningTable() {return diningTable;}public void setDiningTable(Integer diningTable) {this.diningTable = diningTable;}public String getFood_name() {return food_name;}public void setFood_name(String food_name) {this.food_name = food_name;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}@Overridepublic String toString() {System.out.println("就餐号"+"\t"+"账单单号"+"\t\t"+"菜单号"+"\t"+"点餐的份数"+"\t"+"金额"+"\t\t"+"状态"+"\t\t"+"餐桌号"+"\t\t"+"菜名"+"\t\t"+"价格");return id + "\t\t" + billId + "\t\t" + menuId + "\t\t" + nums + "\t\t\t" + money + "\t\t"+state + "\t\t"+diningTable+"\t\t"+food_name+"\t\t"+price+"\n";}}

6：DAO包

(1):BasicDAO

package com.wyj.mhl.dao;import com.wyj.mhl.utils.JDBCUtilsBYDruid;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;/*** dao的父类Basicdao** @param <T>*/
public class BasicDAO<T>{//可以指定具体类型private  QueryRunner qr =  new QueryRunner();//开发dml可以针对任意的表public int update(String sql,Object... parameters){Connection connection = null;try {connection = JDBCUtilsBYDruid.getConnection();int update = qr.update(connection, sql, parameters);return update;} catch (SQLException e) {//将编译异常转换成运行异常throw new  RuntimeException(e);} finally {JDBCUtilsBYDruid.close(null,null,connection);}}//返回多个查询的对象（即查询结果返回多行）/**** @param sql:输入的sql语句* @param clazz：传入一个类的Class对象，比如Actor.class* @param parameters:给sql语句当中的 ？？ 进行赋值* @return*/public List<T> queryMulti(String sql,Class<T> clazz,Object... parameters) {Connection connection = null;try {connection = JDBCUtilsBYDruid.getConnection();List<T> list = qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);return list;} catch (SQLException e) {e.printStackTrace();} finally {JDBCUtilsBYDruid.close(null, null, connection);}return null;}//查询单行的结果public T querySingle(String sql,Class<T> clazz,Object... parameters){Connection connection = null;try {connection = JDBCUtilsBYDruid.getConnection();T query = qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);return query;} catch (SQLException e) {e.printStackTrace();}finally {}return null;}//查询单个数据public Object queryScalar(String sql,Object... paramenters){Connection connection = null;try {connection = JDBCUtilsBYDruid.getConnection();Object query = qr.query(connection, sql, new ScalarHandler<>(), paramenters);return query;} catch (SQLException e) {e.printStackTrace();} finally {JDBCUtilsBYDruid.close(null,null,connection);}return null;}}

(2):BillDAO

package com.wyj.mhl.dao;import com.wyj.mhl.domain.Bill;public class BillDAO extends BasicDAO<Bill>{//继承BasicDAO的一些方法：select,整个表的数据，单行数据（返回一个对象，可以通过get...// 方法获取到一些属性），单个数据，dml操作
}

(3):CostDAO

package com.wyj.mhl.dao;import com.wyj.mhl.domain.Cost;public class CostDAO extends BasicDAO<Cost>{/*** 继承：BasicDAO当中的方法* dml 和 select,可以直接输入sql语句和操作就可以了***/
}

(4):DingtableDAO

package com.wyj.mhl.dao;import com.wyj.mhl.domain.diningTable;public class DingTableDAO extends BasicDAO<diningTable>{/*** 直接继承父类当中的方法，供Service层使用*/
}

（5）：Employee

package com.wyj.mhl.dao;import com.wyj.mhl.domain.Employee;public class EmployeeDAO extends BasicDAO<Employee>{/*** 可以调用父类当中的方法,* 1.查询的整个表，查询单行数据，查询单个数据* 2.dml*/}

(6)；Menu

package com.wyj.mhl.dao;import com.wyj.mhl.domain.Menu;public class MenuDAO extends BasicDAO<Menu>{/*** 继承BasicDAO，这样可以调用其的方法 select(整个表和单个数据和单行数据) 和 dml**/}

(7):MulityDAO

package com.wyj.mhl.dao;import com.wyj.mhl.domain.Mulitytable;public class MulityTableDAO extends BasicDAO<Mulitytable>{}

补充：德鲁伊的配置文件（要根据自己的电脑信息进行相应的修改）

#key=value
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mhl?rewriteBatchedStatements=true
#url=jdbc:mysql://localhost:3306/mhl
username=root
password=wyj
#initial connection Size
initialSize=10
#min idle connecton size
minIdle=5
#max active connection size
maxActive=20
#max wait time (5000 mil seconds)
maxWait=5000

五：相关在数据库中的表

`wyj_dp02`-- 1.创建一个测试表CREATE TABLE text01(id INT KEY AUTO_INCREMENT,`name` VARCHAR(32)
);DROP TABLE text01;INSERT INTO text01VALUES(1,'王永杰'),(NULL,'王大爷'),(NULL,'王二爷');SELECT * FROM text01;-- 员工表-- 字段(创建表 employee表(主键id, empId,name,pwd,jb等)
CREATE TABLE employee(id INT  PRIMARY KEY AUTO_INCREMENT,empId  VARCHAR(32) UNIQUE NOT NULL DEFAULT '', -- 员工号pwd CHAR(32) NOT NULL DEFAULT '',-- 加密密码`name` VARCHAR(32) NOT NULL DEFAULT '',-- 名字job VARCHAR(20) NOT NULL DEFAULT '' -- 工作 
);INSERT INTO employeeVALUES(NULL,"9912",MD5("123456"),'王大美','经理'),(NULL,"9913",MD5("123456"),'王小美','服务员'),(NULL,"9914",MD5("123456"),'王大力','收银员'),(NULL,"9915",MD5("123456"),'王永杰','经理');DROP TABLE employee	DELETE FROM employeeWHERE id  = 6;SELECT * FROM employee;	-- 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 ''-- 预定人的电话
)CHARSET=utf8;INSERT INTO diningTable VALUES(NULL,'空','','');
INSERT INTO diningTable VALUES(NULL,'空','','');
INSERT INTO diningTable VALUES(NULL,'空','','');SELECT * FROM diningTableDROP TABLE diningtableUPDATE diningTable SET state = '已预定',orderName = "jack",orderTel = "00999"WHERE id = 6;
UPDATE diningTable SET state = '空'WHERE id = 1;-- 菜单表 menuCREATE TABLE menu(id INT PRIMARY KEY AUTO_INCREMENT,food_name VARCHAR(32) NOT NULL DEFAULT '', -- 菜品名food_class VARCHAR(32) NOT NULL DEFAULT '',-- 类别price DOUBLE NOT NULL DEFAULT 0.0	
);INSERT INTO menuVALUES(1,"八宝饭","主食",10.0),(NULL,"叉烧包","主食",20.0),(NULL,"宫保鸡丁","热菜",20.0),(NULL,"糖醋鲤鱼","热菜",120.0);SELECT * FROM menu;-- 创建账单表
-- 字段:(id,biilid,menuid,nums,billdate,money,state,diningTable)CREATE TABLE bill(id INT PRIMARY KEY AUTO_INCREMENT,-- 自增主键billId VARCHAR(50) NOT NULL DEFAULT'', -- 账单号menuId INT NOT NULL DEFAULT 0,-- 菜单编号nums INT NOT NULL DEFAULT 0,-- 菜的份数money DOUBLE NOT NULL DEFAULT 0,-- 花的钱state VARCHAR(32) NOT NULL DEFAULT '', -- 餐桌的状态 结账，未结账，挂单，现金，支付宝billdate DATETIME
);ALTER TABLE billADD diningTable INT NOT NULL DEFAULT 0;-- 餐桌号SELECT * FROM bill;DROP TABLE bill;DELETE FROM bill WHERE id = 3;DELETE FROM diningTable WHERE id = 2;
SELECT * FROM diningTable;SELECT * FROM menu WHERE id = 1;SELECT * FROM diningTable WHERE id = 1UPDATE bill SET state = "就餐中" WHERE diningTable = 1;SELECT * FROM menu;
SELECT * FROM bill;SELECT bill.*,food_nameFROM menu,billWHERE menu.id = bill.menuId;SELECT bill.*,food_name FROM menu,bill WHERE menu.id = bill.menuId-- 成本控制表（date,electricity,water,people,food）CREATE TABLE cost(`date` VARCHAR(32) NOT NULL DEFAULT '',electricity DOUBLE NOT NULL DEFAULT 0, -- 电费water DOUBLE NOT NULL DEFAULT 0, -- 水费people DOUBLE NOT NULL DEFAULT 0, -- 人工费food DOUBLE NOT NULL DEFAULT 0 -- 食品费
);DROP TABLE cost;INSERT INTO costVALUES('2019—12-11',1200,200,3000,4000),('2019—12-12',1300,200,2000,6000),('2019—12-13',1400,400,1000,8000),('2019—12-14',1300,500,4000,2000),('2019—12-15',1400,700,2000,1000);SELECT * FROM cost;SELECT * FROM cost

六:总结

兄弟们满汉楼是学完jdbc和mysql后可以用来巩固你知识的，而且仅仅是在控制台展示，是比较low的，但学习是循序渐进的，加油BOY！！！！！，我们共勉，还有的是这是最后一次上传这么长的码，太傻了，我以为不多呢，太费时间了，下次直接上传文件源码！！！加油加油加油！！！！！!!！！！!!！!!！!!！!！!!!！! 多吃核桃哈哈哈哈哈哈