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Java小项目--满汉楼

news 2025/9/2 6:19:55

Java小项目–满汉楼

项目需求

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项目实现

1.实现对工具包的编写

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先创建libs包完成对jar包的拷贝和添加入库
德鲁伊工具包

package com.wantian.mhl.utils;import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;public class JDBCUtilsDruid {private static DataSource ds;static {Properties properties = new Properties();try {properties.load(new FileInputStream("src\\druid.properties"));ds = DruidDataSourceFactory.createDataSource(properties);} catch (Exception e) {throw new RuntimeException(e);}}public static Connection getConnection() throws SQLException {return ds.getConnection();}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){throw new RuntimeException();}}
}

工具包

package com.wantian.mhl.utils;/**工具类的作用:处理各种情况的用户输入，并且能够按照程序员的需求，得到用户的控制台输入。
*/import java.util.*;
/***/
public class Utility {//静态属性。。。private static Scanner scanner = new Scanner(System.in);/*** 功能：读取键盘输入的一个菜单选项，值：1——5的范围* @return 1——5*/public static char readMenuSelection() {char c;for (; ; ) {String str = readKeyBoard(1, false);//包含一个字符的字符串c = str.charAt(0);//将字符串转换成字符char类型if (c != '1' && c != '2' && c != '3' && c != '4' && c != '5') {System.out.print("选择错误，请重新输入：");} else break;}return c;}/*** 功能：读取键盘输入的一个字符* @return 一个字符*/public static char readChar() {String str = readKeyBoard(1, false);//就是一个字符return str.charAt(0);}/*** 功能：读取键盘输入的一个字符，如果直接按回车，则返回指定的默认值；否则返回输入的那个字符* @param defaultValue 指定的默认值* @return 默认值或输入的字符*/public static char readChar(char defaultValue) {String str = readKeyBoard(1, true);//要么是空字符串，要么是一个字符return (str.length() == 0) ? defaultValue : str.charAt(0);}/*** 功能：读取键盘输入的整型，长度小于2位* @return 整数*/public static int readInt() {int n;for (; ; ) {String str = readKeyBoard(2, false);//一个整数，长度<=2位try {n = Integer.parseInt(str);//将字符串转换成整数break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的 整数或默认值，如果直接回车，则返回默认值，否则返回输入的整数* @param defaultValue 指定的默认值* @return 整数或默认值*/public static int readInt(int defaultValue) {int n;for (; ; ) {String str = readKeyBoard(10, true);if (str.equals("")) {return defaultValue;}//异常处理...try {n = Integer.parseInt(str);break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的指定长度的字符串* @param limit 限制的长度* @return 指定长度的字符串*/public static String readString(int limit) {return readKeyBoard(limit, false);}/*** 功能：读取键盘输入的指定长度的字符串或默认值，如果直接回车，返回默认值，否则返回字符串* @param limit 限制的长度* @param defaultValue 指定的默认值* @return 指定长度的字符串*/public static String readString(int limit, String defaultValue) {String str = readKeyBoard(limit, true);return str.equals("")? defaultValue : str;}/*** 功能：读取键盘输入的确认选项，Y或N* 将小的功能，封装到一个方法中.* @return Y或N*/public static char readConfirmSelection() {System.out.println("请输入你的选择(Y/N)");char c;for (; ; ) {//无限循环//在这里，将接受到字符，转成了大写字母//y => Y n=>NString str = readKeyBoard(1, false).toUpperCase();c = str.charAt(0);if (c == 'Y' || c == 'N') {break;} else {System.out.print("选择错误，请重新输入：");}}return c;}/*** 功能： 读取一个字符串* @param limit 读取的长度* @param blankReturn 如果为true ,表示 可以读空字符串。 * 					  如果为false表示 不能读空字符串。* 			*	如果输入为空，或者输入大于limit的长度，就会提示重新输入。* @return*/private static String readKeyBoard(int limit, boolean blankReturn) {//定义了字符串String line = "";//scanner.hasNextLine() 判断有没有下一行while (scanner.hasNextLine()) {line = scanner.nextLine();//读取这一行//如果line.length=0, 即用户没有输入任何内容，直接回车if (line.length() == 0) {if (blankReturn) return line;//如果blankReturn=true,可以返回空串else continue; //如果blankReturn=false,不接受空串，必须输入内容}//如果用户输入的内容大于了 limit，就提示重写输入  //如果用户如的内容 >0 <= limit ,我就接受if (line.length() < 1 || line.length() > limit) {System.out.print("输入长度（不能大于" + limit + "）错误，请重新输入：");continue;}break;}return line;}
}

2.初步编写界面

package com.wantian.mhl.view;import com.wantian.mhl.utils.Utility;public class MHLView {// 控制是否退出菜单private boolean loop = true;private String key = "";public static void main(String[] args) {new MHLView().mainMenu();}//显示主菜单public void mainMenu() {while (loop) {System.out.println("==============满汉楼===============");System.out.println("\t\t 1 登录满汉楼");System.out.println("\t\t 2 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.print("请输入员工号: ");String id = Utility.readString(50);System.out.print("请输入密  码: ");String pwd = Utility.readString(50);//到数据库去判断if (pwd.equals("123")){System.out.println("================登录成功===============\n");//显示二级菜单while (loop){System.out.println("==============满汉楼(二级菜单)===============");System.out.println("\t\t 1 显示餐桌状态");System.out.println("\t\t 2 预订餐桌");System.out.println("\t\t 3 显示所有菜品");System.out.println("\t\t 4 点餐服务");System.out.println("\t\t 5 查看菜单");System.out.println("\t\t 6 结账");System.out.println("\t\t 9 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("显示餐桌状态");break;case "2":System.out.println("预订餐桌");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===============\n");}break;case "2":System.out.println("退出满汉楼");loop = false;break;default:System.out.println("你输入有误，请重新输入");}}}
}

3.创建Employee表，domain（类）,EmployeeDAO和BasicDAO

创建Employee表

-- 创建满汉楼的表--
CREATE DATABASE mhl;
#用户表emplyee表(主键id,empId,name,pwd,job等)
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; -- 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, '666', MD5('123456'), '老韩', '经理');

创建Employee类

package com.wantian.mhl.domain;/*** id INT PRIMARY KEY AUTO_INCREMENT, #自增* 	empId VARCHAR(50) NOT NULL DEFAULT '',#员工号* 	pwd CHAR(32) NOT NULL DEFAULT '',#密码md5* 	NAME VARCHAR(50) NOT NULL DEFAULT '',#姓名* 	job VARCHAR(50) NOT NULL DEFAULT '' #岗位*/
public class Employee {private Integer id;private String empId;private String pwd;private String name;private String job;public Employee() {}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;}
}

创建BasicDAO表

package com.wantian.mhl.dao;import com.wantian.mhl.utils.JDBCUtilsDruid;
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;public class BasicDAO <T>{private QueryRunner qr = new QueryRunner();private int update(String sql,Object...parameters){Connection connection = null;try {connection= JDBCUtilsDruid.getConnection();int update = qr.update(sql, parameters);return update;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public List<T> queryMultiply(String sql,Class<T> clazz,Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();List<T> query = qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public T querySingle(String sql,Class<T> clazz,Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();T query = qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public Object queryScalar(String sql,Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();Object query = qr.query(connection, sql, new ScalarHandler(), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}
}

创建EmployeeDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.Employee;public class EmployeeDAO extends BasicDAO<Employee>{//这里可以写特有的操作
}

4.创建一个EmployeeService

package com.wantian.mhl.service;import com.wantian.mhl.dao.EmployeeDAO;
import com.wantian.mhl.domain.Employee;/*** 该类完成对employee表的各种业务操作*/
public class EmployeeService {//定义一个Employee属性private EmployeeDAO employeeDAO = new EmployeeDAO();//方法，根据 empId 和 pwd 返回一个Employee对象//如果查询不到，就返回一个nullpublic Employee getEmployeeByIdAndPwd(String empId,String pwd){Employee employee =employeeDAO.querySingle("select * from employee where empId = ? and pwd = md5(?)", Employee.class, empId, pwd);return employee;}
}

然后将其添加到菜单界面进行判定
这个位置

Employee employee = employeeService.getEmployeeByIdAndPwd(empId, pwd);//到数据库去判断if (employee != null){System.out.println("================登录成功["+ employee.getName() + "]===============\n");

5.创建Dining表，domain（类DiningTable），DiningTableDAO，DingTableService

创建dining表

-- 创建dining表（id，state，orderName等）
#餐桌表
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; INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');

创建DiningTable

package com.wantian.mhl.domain;/*** 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 ;}
}

创建DiningTableDAO

package com.wantian.mhl.dao;public class DiningTableDAO extends BasicDAO<DiningTable>{//如果有特殊操作可以添加
}

创建DiningTableService

package com.wantian.mhl.service;import com.wantian.mhl.dao.DiningTableDAO;
import com.wantian.mhl.domain.DiningTable;import java.util.List;public class DiningTableService {// 定义一个DiningTableDAO对象private DiningTableDAO diningTableDAO = new DiningTableDAO();public List<DiningTable> list() {List<DiningTable> diningTables = diningTableDAO.queryMultiply("select id, state from diningTable", DiningTable.class);return diningTables;}

6.完成对餐桌的预订

检测餐桌是否存在和餐桌的状态

//根据id,查询对应的餐桌DiningTable 对象//如果返回null，表示id编号对应的餐桌不存在public DiningTable getDiningTableById(int id){return diningTableDAO.querySingle("select * from diningTable where id = ?",DiningTable.class,id);}//如果餐桌可以预订,调用方法,对其状态进行更新（包括预订人的名字和电话）public boolean orderDiningTable(int id,String orderName,String orderTel){int update = diningTableDAO.update("update diningTable set state = '已经预订',orderName = ?,orderTel = ? where id = ?", orderName, orderTel, id);return update > 0;}

然后编写进入界面

public void orderDiningTable(){System.out.println("=============预订餐桌==============");System.out.println("请选择要预订餐桌的编号(-1 表示退出预订)");int orderId = Utility.readInt();if (orderId == -1){System.out.println("==============取消预订餐桌================");return;}char key = Utility.readConfirmSelection();if (key == 'Y'){// 根据orderId，返回对应DiningTable对象，如果为null，说明该对象不存在DiningTable diningTable = diningTableService.getDiningTableById(orderId);if (diningTable == null){System.out.println("餐桌不存在");return;}//判断该餐桌状态是否为“空”if(!("空".equals(diningTable.getState()))){System.out.println("==============餐桌已被预订==============");return;}//这时,得到相关信息并完成预订System.out.print("请输入预订人的名字");String orderName = Utility.readString(50);System.out.print("请输入预订人的电话：");String orderTel = Utility.readString(50);if(diningTableService.orderDiningTable(orderId,orderName,orderTel)) {System.out.println("===============预订餐桌成功==============");}else {System.out.println("===============预订餐桌失败==============");}}else {System.out.println("==================取消预订餐桌===============");}}

7.创建menu表，domain类，和MenuDAO，MenuService

创建menu表

#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; insert into menu values(null, '八宝饭', '主食类', 10);
insert into menu values(null, '叉烧包', '主食类', 20);
insert into menu values(null, '宫保鸡丁', '热菜类', 30);
insert into menu values(null, '山药拨鱼', '凉菜类', 14);
insert into menu values(null, '银丝卷', '甜食类', 9);
insert into menu values(null, '水煮鱼', '热菜类', 26);
insert into menu values(null, '甲鱼汤', '汤类', 100);
insert into menu values(null, '鸡蛋汤', '汤类', 16);

Menu类

package com.wantian.mhl.domain;/*** 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*/
public class Menu {private Integer id;private String name;private String type;private Double price;public Menu() {}public Menu(Integer id, String name, String type, Double price) {this.id = id;this.name = name;this.type = type;this.price = price;}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;}
}

创建MenuDAO

public class MenuDAO extends BasicDAO<Menu>{//这里可以创建特殊方法
}

创建MenuService

package com.wantian.mhl.service;import com.wantian.mhl.dao.MenuDAO;
import com.wantian.mhl.domain.Menu;import java.util.List;public class MenuService {//定义MenuDAOprivate MenuDAO menuDAO = new MenuDAO();//返回所有的菜品public List<Menu> list(){return menuDAO.queryMultiply("select * from menu",Menu.class);}}

创建bill表，bill类，BillDAO，BillService

创建bill表

#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 SMALLINT 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'
)charset=utf8;

创建bill类

package com.wantian.mhl.domain;import java.util.Date;/***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 SMALLINT 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'*/
public class Bill {private Integer id;private String billId;private Integer menuId;private Integer numbers;private Double money;private Integer diningId;private Date billDate;private String state;public Bill() {}public Bill(Integer id, String billId, Integer menuId, Integer numbers, Double money, Integer diningId, Date billDate, String state) {this.id = id;this.billId = billId;this.menuId = menuId;this.numbers = numbers;this.money = money;this.diningId = diningId;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 getNumbers() {return numbers;}public void setNumbers(Integer numbers) {this.numbers = numbers;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningId() {return diningId;}public void setDiningId(Integer diningId) {this.diningId = diningId;}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;}
}

创建BillDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.Bill;public class BillDAO extends BasicDAO<Bill>{//这里可以进行特殊方法的添加
}

进行BillService编写

package com.wantian.mhl.service;import com.wantian.mhl.dao.BasicDAO;
import com.wantian.mhl.dao.BillDAO;
import com.wantian.mhl.domain.Menu;import java.util.UUID;public class BillService {// 定义BillDAO属性private BillDAO billDAO = new BillDAO();// 定义MenuServiceprivate MenuService menuService = new MenuService();// 定义DiningTableServiceprivate DiningTableService diningTableService = new DiningTableService();// 编写点餐的方法// 1.生成菜单// 2.需要更新餐桌的状态public boolean orderMenu(int menuId,int numbers,int diningTableId){// 生成一个账单号,UUIDString billId = UUID.randomUUID().toString();// 将账单生成到bill表// 需要计算账单金额int update = billDAO.update("insert into bill values(null,?,?,?,?,?,now(),'未结账')", billId, menuId, numbers, menuService.getMenuById(menuId).getPrice() * numbers, diningTableId);if(update <= 0){return false;}return diningTableService.updateDiningTableState(diningTableId,"就餐中");}}

这里在其它的如DiningTableService里，增加了特殊方法，来设置状态

public boolean updateDiningTableState(int id,String state){int update = diningTableDAO.update("update diningTable set state = ? where id = ?", state, id);return update > 0;}

编写界面和判断数据是否合理

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.println("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.println("请输入点餐的菜品量(-1退出): ");int orderNumbers = Utility.readInt();if (orderNumbers == -1){System.out.println("=============取消点餐=============");return;}// 验证数据是否存在(餐桌)DiningTable diningTable = diningTableService.getDiningTableById(orderDiningTableId);if (diningTable == null){System.out.println("===============餐桌不存在==============");return;}// 验证菜品编号Menu menu = menuService.getMenuById(orderMenuId);if (menu == null){System.out.println("===============菜品不存在===============");return;}if(billService.orderMenu(orderMenuId,orderNumbers,orderDiningTableId)){System.out.println("===============点餐成功=================");}else {System.out.println("===============点餐失败=================");}}

返回查询账单

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===============");}

实现结账

编写设置状态的方法

public boolean updateDiningTableToFree(int id,String state){int update = diningTableDAO.update("update diningTable set state = ? ,orderName = ' ', orderTel = ' ',where id = ?", state, id);return update > 0;}

编写提交账单方法

public boolean payBill(int diningTableId,String payMode) {// 1. 修改bill表int update = billDAO.update("update bill set state = ? where diningTableId = ? and state = '未结账'", payMode, diningTableId);if (update <= 0){return false;}//如果更新没有成功，表示失败// 2. 修改diningTable表if (!diningTableService.updateDiningTableToFree(diningTableId,"空")){return false;}return true;}

界面编写结账

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("================餐桌不存在=================");return;}// 验证该餐桌账单是否存在if (!(billService.hasPayBillByDiningTableId(diningTableId))){System.out.println("================已经结账了================");return;}System.out.print("请选择要结账的方式(现金/支付宝/微信)(回车表示退出)");String payMode = Utility.readString(20,"");// 如果回车，返回空串if ("".equals(payMode)){System.out.println("===============取消结账==============");return;}char key = Utility.readConfirmSelection();if (key == 'Y'){// 完成结账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===============");}}

完成一个多表映射

完成多表账单的编写

package com.wantian.mhl.domain;import java.util.Date;public class MultiTableBean {// 和多张表进行映射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，nameprivate String name;public MultiTableBean() {}public MultiTableBean(Integer id, String billId, Integer menuId, Integer nums, Double money, Integer diningTableId, Date billDate, String state, String name) {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;}public 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 getNumbers() {return nums;}public void setNumbers(Integer numbers) {this.nums = numbers;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningId() {return diningTableId;}public void setDiningId(Integer diningId) {this.diningTableId = diningId;}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;}public Integer getNums() {return nums;}public void setNums(Integer nums) {this.nums = nums;}public Integer getDiningTableId() {return diningTableId;}public void setDiningTableId(Integer diningTableId) {this.diningTableId = diningTableId;}@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;}
}

完成对返回账单的升级（多表查询）

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===============");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");for (MultiTableBean multiTableBean : multiTableBeans) {System.out.println(multiTableBean);}}

view

package com.wantian.mhl.view;import com.wantian.mhl.domain.*;
import com.wantian.mhl.service.BillService;
import com.wantian.mhl.service.DiningTableService;
import com.wantian.mhl.service.EmployeeService;
import com.wantian.mhl.service.MenuService;
import com.wantian.mhl.utils.Utility;import java.util.List;public class MHLView {// 控制是否退出菜单private boolean loop = true;private String key = "";private EmployeeService employeeService = new EmployeeService();private DiningTableService diningTableService = new DiningTableService();private MenuService menuService = new MenuService();private BillService billService = new BillService();public static void main(String[] args) {new MHLView().mainMenu();}//显示主菜单public void mainMenu() {while (loop) {System.out.println("==============满汉楼===============");System.out.println("\t\t 1 登录满汉楼");System.out.println("\t\t 2 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.print("请输入员工号: ");String empId = Utility.readString(50);System.out.print("请输入密  码: ");String pwd = Utility.readString(50);Employee employee = employeeService.getEmployeeByIdAndPwd(empId, pwd);//到数据库去判断if (employee != null){System.out.println("================登录成功["+ employee.getName() + "]===============\n");//显示二级菜单while (loop){System.out.println("==============满汉楼(二级菜单)===============");System.out.println("\t\t 1 显示餐桌状态");System.out.println("\t\t 2 预订餐桌");System.out.println("\t\t 3 显示所有菜品");System.out.println("\t\t 4 点餐服务");System.out.println("\t\t 5 查看账单");System.out.println("\t\t 6 结账");System.out.println("\t\t 9 退出满汉楼");System.out.println("请输入你的选择");key = Utility.readString(1);switch (key){case "1":listDiningTable();break;case "2":orderDiningTable();break;case "3":listMenu();break;case "4":orderMenu();break;case "5":listBill();break;case "6":payBill();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===============\n");}break;case "2":System.out.println("退出满汉楼");loop = false;break;default:System.out.println("你输入有误，请重新输入");}}}//显示所有菜品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\t价格");for (Menu menu : list) {System.out.println(menu);}System.out.println("================显示完毕===============");}// 显示所有餐桌状态public void listDiningTable(){List<DiningTable> list = diningTableService.list();System.out.println("\n餐桌编号\t\t餐桌状态");for (DiningTable diningTable : list) {System.out.println(diningTable);}System.out.println("==============显示完毕==============");}// 完成预订餐桌public void orderDiningTable(){System.out.println("=============预订餐桌==============");System.out.println("请选择要预订餐桌的编号(-1 表示退出预订)");int orderId = Utility.readInt();if (orderId == -1){System.out.println("==============取消预订餐桌================");return;}char key = Utility.readConfirmSelection();if (key == 'Y'){// 根据orderId，返回对应DiningTable对象，如果为null，说明该对象不存在DiningTable diningTable = diningTableService.getDiningTableById(orderId);if (diningTable == null){System.out.println("餐桌不存在");return;}//判断该餐桌状态是否为“空”if(!("空".equals(diningTable.getState()))){System.out.println("==============餐桌已被预订==============");return;}//这时,得到相关信息并完成预订System.out.print("请输入预订人的名字");String orderName = Utility.readString(50);System.out.print("请输入预订人的电话：");String orderTel = Utility.readString(50);if(diningTableService.orderDiningTable(orderId,orderName,orderTel)) {System.out.println("===============预订餐桌成功==============");}else {System.out.println("===============预订餐桌失败==============");}}else {System.out.println("==================取消预订餐桌===============");}}// 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.println("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.println("请输入点餐的菜品量(-1退出): ");int orderNumbers = Utility.readInt();if (orderNumbers == -1){System.out.println("=============取消点餐=============");return;}// 验证数据是否存在(餐桌)DiningTable diningTable = diningTableService.getDiningTableById(orderDiningTableId);if (diningTable == null){System.out.println("===============餐桌不存在==============");return;}// 验证菜品编号Menu menu = menuService.getMenuById(orderMenuId);if (menu == null){System.out.println("===============菜品不存在===============");return;}if(billService.orderMenu(orderMenuId,orderNumbers,orderDiningTableId)){System.out.println("===============点餐成功=================");}else {System.out.println("===============点餐失败=================");}}// 显示账单信息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===============");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 multiTableBean : multiTableBeans) {System.out.println(multiTableBean);}}// 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("================餐桌不存在=================");return;}// 验证该餐桌账单是否存在if (!(billService.hasPayBillByDiningTableId(diningTableId))){System.out.println("================已经结账了================");return;}System.out.print("请选择要结账的方式(现金/支付宝/微信)(回车表示退出)");String payMode = Utility.readString(20,"");// 如果回车，返回空串if ("".equals(payMode)){System.out.println("===============取消结账==============");return;}char key = Utility.readConfirmSelection();if (key == 'Y'){// 完成结账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===============");}}
}

Utils

Utility

package com.wantian.mhl.utils;/**工具类的作用:处理各种情况的用户输入，并且能够按照程序员的需求，得到用户的控制台输入。
*/import java.util.*;
/***/
public class Utility {//静态属性。。。private static Scanner scanner = new Scanner(System.in);/*** 功能：读取键盘输入的一个菜单选项，值：1——5的范围* @return 1——5*/public static char readMenuSelection() {char c;for (; ; ) {String str = readKeyBoard(1, false);//包含一个字符的字符串c = str.charAt(0);//将字符串转换成字符char类型if (c != '1' && c != '2' && c != '3' && c != '4' && c != '5') {System.out.print("选择错误，请重新输入：");} else break;}return c;}/*** 功能：读取键盘输入的一个字符* @return 一个字符*/public static char readChar() {String str = readKeyBoard(1, false);//就是一个字符return str.charAt(0);}/*** 功能：读取键盘输入的一个字符，如果直接按回车，则返回指定的默认值；否则返回输入的那个字符* @param defaultValue 指定的默认值* @return 默认值或输入的字符*/public static char readChar(char defaultValue) {String str = readKeyBoard(1, true);//要么是空字符串，要么是一个字符return (str.length() == 0) ? defaultValue : str.charAt(0);}/*** 功能：读取键盘输入的整型，长度小于2位* @return 整数*/public static int readInt() {int n;for (; ; ) {String str = readKeyBoard(2, false);//一个整数，长度<=2位try {n = Integer.parseInt(str);//将字符串转换成整数break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的 整数或默认值，如果直接回车，则返回默认值，否则返回输入的整数* @param defaultValue 指定的默认值* @return 整数或默认值*/public static int readInt(int defaultValue) {int n;for (; ; ) {String str = readKeyBoard(10, true);if (str.equals("")) {return defaultValue;}//异常处理...try {n = Integer.parseInt(str);break;} catch (NumberFormatException e) {System.out.print("数字输入错误，请重新输入：");}}return n;}/*** 功能：读取键盘输入的指定长度的字符串* @param limit 限制的长度* @return 指定长度的字符串*/public static String readString(int limit) {return readKeyBoard(limit, false);}/*** 功能：读取键盘输入的指定长度的字符串或默认值，如果直接回车，返回默认值，否则返回字符串* @param limit 限制的长度* @param defaultValue 指定的默认值* @return 指定长度的字符串*/public static String readString(int limit, String defaultValue) {String str = readKeyBoard(limit, true);return str.equals("")? defaultValue : str;}/*** 功能：读取键盘输入的确认选项，Y或N* 将小的功能，封装到一个方法中.* @return Y或N*/public static char readConfirmSelection() {System.out.println("请输入你的选择(Y/N)");char c;for (; ; ) {//无限循环//在这里，将接受到字符，转成了大写字母//y => Y n=>NString str = readKeyBoard(1, false).toUpperCase();c = str.charAt(0);if (c == 'Y' || c == 'N') {break;} else {System.out.print("选择错误，请重新输入：");}}return c;}/*** 功能： 读取一个字符串* @param limit 读取的长度* @param blankReturn 如果为true ,表示 可以读空字符串。 * 					  如果为false表示 不能读空字符串。* 			*	如果输入为空，或者输入大于limit的长度，就会提示重新输入。* @return*/private static String readKeyBoard(int limit, boolean blankReturn) {//定义了字符串String line = "";//scanner.hasNextLine() 判断有没有下一行while (scanner.hasNextLine()) {line = scanner.nextLine();//读取这一行//如果line.length=0, 即用户没有输入任何内容，直接回车if (line.length() == 0) {if (blankReturn) return line;//如果blankReturn=true,可以返回空串else continue; //如果blankReturn=false,不接受空串，必须输入内容}//如果用户输入的内容大于了 limit，就提示重写输入  //如果用户如的内容 >0 <= limit ,我就接受if (line.length() < 1 || line.length() > limit) {System.out.print("输入长度（不能大于" + limit + "）错误，请重新输入：");continue;}break;}return line;}
}

JDBCUtilsDruid

package com.wantian.mhl.utils;import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;public class JDBCUtilsDruid {private static DataSource ds;static {Properties properties = new Properties();try {properties.load(new FileInputStream("src\\druid.properties"));ds = DruidDataSourceFactory.createDataSource(properties);} catch (Exception e) {throw new RuntimeException(e);}}public static Connection getConnection() throws SQLException {return ds.getConnection();}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){throw new RuntimeException();}}
}

Service

BillService

package com.wantian.mhl.service;import com.wantian.mhl.dao.BasicDAO;
import com.wantian.mhl.dao.BillDAO;
import com.wantian.mhl.dao.MultiTableDAO;
import com.wantian.mhl.domain.Bill;
import com.wantian.mhl.domain.Menu;
import com.wantian.mhl.domain.MultiTableBean;import java.util.List;
import java.util.UUID;public class BillService {// 定义BillDAO属性private BillDAO billDAO = new BillDAO();// 定义MenuServiceprivate MenuService menuService = new MenuService();private MultiTableDAO multiTableDAO = new MultiTableDAO();// 定义DiningTableServiceprivate DiningTableService diningTableService = new DiningTableService();// 编写点餐的方法// 1.生成菜单// 2.需要更新餐桌的状态public boolean orderMenu(int menuId,int numbers,int diningTableId){// 生成一个账单号,UUIDString billId = UUID.randomUUID().toString();// 将账单生成到bill表// 需要计算账单金额int update = billDAO.update("insert into bill values(null,?,?,?,?,?,now(),'未结账')", billId, menuId, numbers, menuService.getMenuById(menuId).getPrice() * numbers, diningTableId);if(update <= 0){return false;}return diningTableService.updateDiningTableState(diningTableId,"就餐中");}// 返回所有的账单，提供给View调用public List<Bill> list(){return billDAO.queryMultiply("select * from bill",Bill.class);}public List<MultiTableBean> list2(){return multiTableDAO.queryMultiply("select bill.*,`name` ,price from bill,menu where bill.menuId = menu.id",MultiTableBean.class);}// 返回所有的账单，并带有菜品名// 查看某张餐桌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;}// 如果餐桌存在，且未结账,就完成结账public boolean payBill(int diningTableId,String payMode) {// 1. 修改bill表int update = billDAO.update("update bill set state = ? where diningTableId = ? and state = '未结账'", payMode, diningTableId);if (update <= 0){return false;}//如果更新没有成功，表示失败// 2. 修改diningTable表if (!diningTableService.updateDiningTableToFree(diningTableId,"空")){return false;}return true;}
}

DiningTableService

package com.wantian.mhl.service;import com.wantian.mhl.dao.DiningTableDAO;
import com.wantian.mhl.domain.DiningTable;import java.util.List;public class DiningTableService {// 定义一个DiningTableDAO对象private DiningTableDAO diningTableDAO = new DiningTableDAO();public List<DiningTable> list() {List<DiningTable> diningTables = diningTableDAO.queryMultiply("select id, state from diningTable", DiningTable.class);return diningTables;}//根据id,查询对应的餐桌DiningTable 对象//如果返回null，表示id编号对应的餐桌不存在public DiningTable getDiningTableById(int id){return diningTableDAO.querySingle("select * from diningTable where id = ?",DiningTable.class,id);}//如果餐桌可以预订,调用方法,对其状态进行更新（包括预订人的名字和电话）public boolean orderDiningTable(int id,String orderName,String orderTel){int update = diningTableDAO.update("update diningTable set state = '已经预订',orderName = ?,orderTel = ? where id = ?", orderName, orderTel, id);return update > 0;}// 需要一个更新餐桌状态的方法public boolean updateDiningTableState(int id,String state){int update = diningTableDAO.update("update diningTable set state = ? where id = ?", state, id);return update > 0;}public boolean updateDiningTableToFree(int id,String state){int update = diningTableDAO.update("update diningTable set state = ? ,orderName = ' ', orderTel = ' ' where id = ?", state, id);return update > 0;}
}

EmployeeService

package com.wantian.mhl.service;import com.wantian.mhl.dao.EmployeeDAO;
import com.wantian.mhl.domain.Employee;/*** 该类完成对employee表的各种业务操作*/
public class EmployeeService {//定义一个Employee属性private EmployeeDAO employeeDAO = new EmployeeDAO();//方法，根据 empId 和 pwd 返回一个Employee对象//如果查询不到，就返回一个nullpublic Employee getEmployeeByIdAndPwd(String empId,String pwd){Employee employee =employeeDAO.querySingle("select * from employee where empId = ? and pwd = md5(?)", Employee.class, empId, pwd);return employee;}
}

MenuService

package com.wantian.mhl.service;import com.wantian.mhl.dao.MenuDAO;
import com.wantian.mhl.domain.Menu;import java.util.List;public class MenuService {//定义MenuDAOprivate MenuDAO menuDAO = new MenuDAO();//返回所有的菜品public List<Menu> list(){return menuDAO.queryMultiply("select * from menu",Menu.class);}// 需要方法，根据id返回Menu对象public Menu getMenuById(int id){return menuDAO.querySingle("select * from menu where id = ?", Menu.class,id);}}

domain

Bill

package com.wantian.mhl.domain;import java.util.Date;/***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 SMALLINT 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'*/
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 numbers, Double money, Integer diningId, Date billDate, String state) {this.id = id;this.billId = billId;this.menuId = menuId;this.nums = numbers;this.money = money;this.diningTableId = diningId;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 getNumbers() {return nums;}public void setNumbers(Integer numbers) {this.nums = numbers;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningId() {return diningTableId;}public void setDiningId(Integer diningId) {this.diningTableId = diningId;}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;}public Integer getNums() {return nums;}public void setNums(Integer nums) {this.nums = nums;}public Integer getDiningTableId() {return diningTableId;}public void setDiningTableId(Integer diningTableId) {this.diningTableId = diningTableId;}@Overridepublic String toString() {return  id +"\t\t" + menuId +"\t\t\t" + nums +"\t\t\t" + money +"\t" + diningTableId +"\t\t" + billDate +"\t\t" + state;}
}

DiningTable

package com.wantian.mhl.domain;/*** 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 ;}

Employee

package com.wantian.mhl.domain;/*** id INT PRIMARY KEY AUTO_INCREMENT, #自增* 	empId VARCHAR(50) NOT NULL DEFAULT '',#员工号* 	pwd CHAR(32) NOT NULL DEFAULT '',#密码md5* 	NAME VARCHAR(50) NOT NULL DEFAULT '',#姓名* 	job VARCHAR(50) NOT NULL DEFAULT '' #岗位*/
public class Employee {private Integer id;private String empId;private String pwd;private String name;private String job;public Employee() {}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;}
}

Menu

package com.wantian.mhl.domain;/*** 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*/
public class Menu {private Integer id;private String name;private String type;private Double price;public Menu() {}public Menu(Integer id, String name, String type, Double price) {this.id = id;this.name = name;this.type = type;this.price = price;}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;}@Overridepublic String toString() {return id + "\t\t\t" + name + "\t\t" + type + "\t\t" + price;}
}

MultiTableBean

package com.wantian.mhl.domain;import java.util.Date;public class MultiTableBean {// 和多张表进行映射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，nameprivate String name;private Double price;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;}public MultiTableBean() {}public MultiTableBean(Integer id, String billId, Integer menuId, Integer nums, Double money, Integer diningTableId, Date billDate, String state, String name) {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;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}public 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 getNumbers() {return nums;}public void setNumbers(Integer numbers) {this.nums = numbers;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public Integer getDiningId() {return diningTableId;}public void setDiningId(Integer diningId) {this.diningTableId = diningId;}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;}public Integer getNums() {return nums;}public void setNums(Integer nums) {this.nums = nums;}public Integer getDiningTableId() {return diningTableId;}public void setDiningTableId(Integer diningTableId) {this.diningTableId = diningTableId;}@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;}
}

DAO

BasicDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.DiningTable;
import com.wantian.mhl.utils.JDBCUtilsDruid;
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;public class BasicDAO <T>{private QueryRunner qr = new QueryRunner();public int update(String sql,Object...parameters){Connection connection = null;try {connection= JDBCUtilsDruid.getConnection();int update = qr.update(connection,sql, parameters);return update;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public List<T> queryMultiply(String sql, Class<T> clazz, Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();List<T> query = qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public T querySingle(String sql,Class<T> clazz,Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();T query = qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}public Object queryScalar(String sql,Object...parameters){Connection connection = null;try {connection = JDBCUtilsDruid.getConnection();Object query = qr.query(connection, sql, new ScalarHandler(), parameters);return query;} catch (SQLException e) {throw new RuntimeException(e);}finally {JDBCUtilsDruid.close(null,null,connection);}}
}

BillDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.Bill;public class BillDAO extends BasicDAO<Bill>{//这里可以进行特殊方法的添加
}

DiningTableDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.DiningTable;public class DiningTableDAO extends BasicDAO<DiningTable>{//如果有特殊操作可以添加}

EmployeeDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.Employee;public class EmployeeDAO extends BasicDAO<Employee>{//这里可以写特有的操作
}

MenuDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.Menu;public class MenuDAO extends BasicDAO<Menu>{//这里可以创建特殊方法
}

MuItiTableDAO

package com.wantian.mhl.dao;import com.wantian.mhl.domain.MultiTableBean;public class MultiTableDAO extends BasicDAO<MultiTableBean>{}

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