满汉楼是一个综合餐饮管理系统,其主要分为:
该项目应用到的核心知识:java+jdbc(druid)+mysql
满汉楼项目有很多界面,这里展示部分:
满汉楼项目的功能比较多,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:
我们先大致弄成以下界面:
项目设计—程序框架图
导入Utility和JDBCUtilsByDruid工具类
#key=value
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/sys_db02?rewriteBatchedStatements=true
#url=jdbc:mysql://localhost:3306/sys_db02
username=root
password=sys
#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
package com.song.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=>N
String 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;
}
}
package com.song.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;
/**
* 基于Druid数据库连接池的工具类
*/
public class JDBCUtilsByDruid {
private static DataSource ds;
//用静态代码块完成 ds 初始化
static{
Properties properties = new Properties();
try {
properties.load(new FileInputStream("src\\druid.properties"));
ds = DruidDataSourceFactory.createDataSource(properties);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
//编写getConnection方法
public static Connection getConncteion() throws SQLException {
return ds.getConnection();
}
//关闭连接
//注意:这里的关闭连接,在数据库连接池技术中,不是真的断掉连接
//而是把使用的Connection对象放回连接池
public static void close(ResultSet resultSet, Statement statement,Connection connection){
try {
if (resultSet!=null){
resultSet.close();
}
if (statement!=null){
statement.close();
}
if (connection!=null){
connection.close();
}
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
对上面两个工具类做个简单的测试,查看是否导入成功
-- 创建满汉楼的数据库
CREATE DATABASE mhl
-- 创建表 employee表(主键id,empid,name,pwd,job等)
CREATE TABLE employee(
id INT PRIMARY KEY AUTO_INCREMENT,-- 主键id,自增
empid VARCHAR(32) UNIQUE NOT NULL DEFAULT '',-- 员工号
pwd CHAR(32) NOT NULL DEFAULT '',-- 密码
NAME VARCHAR(32) NOT NULL DEFAULT '',-- 名字
job VARCHAR(32) NOT NULL DEFAULT ''-- 职位
)CHARSET=utf8;
-- 添加数据
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'), '老孙', '经理');
SELECT * FROM employee;
DROP TABLE employee;
-- 创建表 diningTable 订餐表/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 ''-- 订餐人的电话
)CHARSET=utf8;
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
SELECT * FROM diningTable;
SELECT * FROM diningTable WHERE id = 1;
UPDATE diningTable SET state = '空',orderName = '',orderTel = '' WHERE id = 1;
-- 创建 menu表 菜单表
CREATE TABLE menu(
id INT PRIMARY KEY AUTO_INCREMENT,-- 菜谱编号,主键自增
NAME VARCHAR(32)NOT NULL DEFAULT '',-- 菜品名称
TYPE VARCHAR(32)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);
SELECT * FROM menu;
-- 创建账单bill表(id,billId,menuId,nums,billDate,money,state,diningTableId)
-- 编号 菜品号 菜品量 金额 桌号 日期 状态
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 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','现金','支付宝'
)CHARSET=utf8;
DROP TABLE bill;
SELECT * FROM bill;
-- 验证用
SELECT * FROM bill WHERE diningTableId = 1 AND state = '未结账' LIMIT 0,1;
SELECT * FROM bill WHERE diningTableId = ? AND state = '未结账' LIMIT 0,1;
package com.song.mhl.domain;
/**
* 这是一个javabean和employee对应
*
* id INT PRIMARY KEY AUTO_INCREMENT,-- 主键id,自增
* empid VARCHAR(32) NOT NULL DEFAULT '',-- 员工号
* pwd CHAR(32) NOT NULL DEFAULT '',-- 密码
* NAME VARCHAR(32) NOT NULL DEFAULT '',-- 名字
* job VARCHAR(32) NOT NULL DEFAULT ''-- 职位
*/
public class Employee {
private Integer id;
private String empid;
private String pwd;
private String name;
private String job;
//无参构造器,底层apache-dbutils反射必须需要
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;
}
@Override
public String toString() {
return "Employee{" +
"id=" + id +
", empid='" + empid + '\'' +
", pwd='" + pwd + '\'' +
", name='" + name + '\'' +
", job='" + job + '\'' +
'}';
}
}
package com.song.mhl.domain;
/**
* 这是一个javabean和diningTable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 ''-- 订餐人的电话
*/
public class DiningTable {
private Integer id;
private String state;
private String orderName;
private String orderTel;
//无参构造器,底层apache-dbutils反射必须需要
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;
}
@Override
public String toString() {
return id + "\t\t\t" + state ;
}
}
package com.song.mhl.domain;
/**
* 这是一个javabean和menu对应
*
* id INT PRIMARY KEY AUTO_INCREMENT,-- 菜谱编号,主键自增
* NAME VARCHAR(32)NOT NULL DEFAULT '',-- 菜品名称
* TYPE VARCHAR(32)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;
}
@Override
public String toString() {
return id +
"\t\t\t" + name +
"\t\t" + type +
"\t\t" + price ;
}
}
package com.song.mhl.domain;
import com.song.mhl.service.DiningTableService;
import com.song.mhl.service.MenuService;
import java.util.Date;
/**
* 这是一个javabean和bill对应
*
* 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','现金','支付宝'
*/
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;
//定义一个DiningTableService属性
private DiningTableService diningTableService = new DiningTableService();
//定义一个MenuService属性
private MenuService menuService = new MenuService();
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;
}
@Override
public String toString() {
return id +
"\t\t\t" + menuId +
"\t\t\t" + nums +
"\t\t\t" + money +
"\t\t" + diningTableId +
"\t\t\t" + billDate +
"\t\t" + state;
}
}
package com.song.mhl.dao;
import com.song.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;
/**
* 开发 BasicDAO,是其他 DAO 的父类
*/
public class BasicDAO<T> {//泛型指定具体类型
private QueryRunner qr = new QueryRunner();
//开发通用的 dml 方法,针对任意的表
public int update(String sql,Object...parameters){
Connection connection = null;
try {
connection = JDBCUtilsByDruid.getConncteion();
int update = qr.update(connection, sql, parameters);
return update;
} catch (SQLException e) {
throw new RuntimeException(e);
} finally {
JDBCUtilsByDruid.close(null,null,connection);
}
}
/**
*
* @param sql sql语句,可以有 ?
* @param clazz 传入一个类的Class对象,比如Actor.class
* @param parameters 传入 ? 的具体的值,可以是多个
* @return 根据Actor.class 返回对应的 ArrayList 集合
*/
//返回多个对象(即查询结果是多行的),针对任意表
public List<T> queryMulti(String sql,Class<T> clazz,Object...parameters){
Connection connection = null;
try {
connection = JDBCUtilsByDruid.getConncteion();
return qr.query(connection,sql,new BeanListHandler<>(clazz),parameters);
} catch (SQLException e) {
throw new RuntimeException(e);
} finally {
JDBCUtilsByDruid.close(null,null,connection);
}
}
//查询单行结果的通用方法
public T querySingle(String sql,Class<T> clazz,Object...parameters){
Connection connection = null;
try {
connection = JDBCUtilsByDruid.getConncteion();
return qr.query(connection,sql,new BeanHandler<T>(clazz),parameters);
} catch (SQLException e) {
throw new RuntimeException(e);
} finally {
JDBCUtilsByDruid.close(null,null,connection);
}
}
//查询单行单列结果的通用方法,即返回单值的方法
public Object queryScalar(String sql,Object...parameters){
Connection connection = null;
try {
connection = JDBCUtilsByDruid.getConncteion();
return qr.query(connection,sql,new ScalarHandler(),parameters);
} catch (SQLException e) {
throw new RuntimeException(e);
} finally {
JDBCUtilsByDruid.close(null,null,connection);
}
}
}
package com.song.mhl.dao;
import com.song.mhl.domain.Employee;
public class EmployeeDAO extends BasicDAO<Employee>{
//这里还可以写特有的操作
}
package com.song.mhl.dao;
import com.song.mhl.domain.DiningTable;
public class DiningTableDAO extends BasicDAO<DiningTable>{
//还可以添加自己特有的方法
}
package com.song.mhl.dao;
import com.song.mhl.domain.Menu;
import java.util.List;
public class MenuDAO extends BasicDAO<Menu>{
//这里还可以写特有的操作
}
package com.song.mhl.dao;
import com.song.mhl.domain.Bill;
public class BillDAO extends BasicDAO<Bill>{
//这里还可以写特有的操作
}
package com.song.mhl.service;
import com.song.mhl.dao.EmployeeDAO;
import com.song.mhl.domain.Employee;
/**
* 该类完成对employee表的各种操作(通过调用EmployeeDAO对象完成)
*/
public class EmployeeService {
//定义一个EmployeeDAO属性
private EmployeeDAO employeeDAO = new EmployeeDAO();
//写一个方法,根据empid和pwd返回一个Employee对象
public Employee getEmployeeByIdAndPwd(String empid,String pwd){
Employee employee = employeeDAO.querySingle
("select * from employee where empid = ? and pwd = md5(?)", Employee.class, empid, pwd);
return employee;
}
}
package com.song.mhl.service;
import com.song.mhl.dao.DiningTableDAO;
import com.song.mhl.domain.DiningTable;
import java.util.List;
/**
* 该类完成对diningTable表的各种操作(通过调用DiningTableDAO对象完成)
*/
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(){
List<DiningTable> diningTables = diningTableDAO.queryMulti
("select id,state from diningTable", DiningTable.class);
return diningTables;
}
//根据id检测餐桌是否存在
//如果DiningTable对象为空,表示id编号对应的餐桌不存在
public DiningTable getDiningTableById(int id){
//小技巧:每次写完SQL语句,把SQL语句放在查询分析器测试一下
DiningTable diningTable = diningTableDAO.querySingle
("select * from diningTable where id = ?", DiningTable.class, id);
return diningTable;
//或者直接写为一句
/*
return diningTableDAO.querySingle
("select * from diningTable where id = ?", DiningTable.class, id);
*/
}
//如果餐桌可以预定,创建一个方法,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 state,String orderName,String orderTel){
int update = diningTableDAO.update
("update diningTable set state = '已经预定',orderName = ?,orderTel = ? " +
"where id = ?", orderName, orderTel,id);
return update > 0;
}
//需要提供一个更新 餐桌状态的方法,用于BillService
public boolean updateDiningTableState(int id,String state){
int update = diningTableDAO.update("update diningTable set state = ? where id = ?", state, id);
return update > 0;
}
//提供方法,将指定的餐桌设置为空闲状态
public boolean updateDiningTableToFree(int id,String state){
int update = diningTableDAO.update("update diningTable set state = ?,orderName = '',orderTel = '' where id = ?", state, id);
return update > 0;
}
}
package com.song.mhl.service;
import com.song.mhl.dao.MenuDAO;
import com.song.mhl.domain.Menu;
import java.util.List;
/**
* 该类完成对menu表的各种操作(通过调用MenuDAO对象完成)
*/
public class MenuService {
//定义一个MenuDAO对象
private MenuDAO menuDAO = new MenuDAO();
//返回所有菜单
public List<Menu> list() {
return menuDAO.queryMulti("select * from menu", Menu.class);
}
//需要创建一个方法,根据id返回menu对象,用于BillService
public Menu getMenuById(int id){
return menuDAO.querySingle("select * from menu where id = ?",Menu.class,id);
}
}
package com.song.mhl.service;
import com.song.mhl.dao.BillDAO;
import com.song.mhl.domain.Bill;
import java.util.List;
import java.util.UUID;
/**
* 该类完成对bill表的各种操作(通过调用BillDAO对象完成)
*/
public class BillService {
//定义一个BillDAO对象
private BillDAO billDAO = new BillDAO();
//定义一个MenuService对象
private MenuService menuService = new MenuService();
//定义一个DiningTableService对象
private DiningTableService diningTableService = new DiningTableService();
//思路
//编写点餐的方法
//1.生成账单
//2.需要更新对应餐桌的状态
//3.如果成功返回true,否则返回false
public boolean orderMenu(int menuId,int nums,int diningTableId){
//生成一个账单号 通过UUID
//UUID.randomUUID().toString(); 每次随机生成一个id且不重复
String billId = UUID.randomUUID().toString();
//将账单生成到bill表,要求直接计算账单金额
int update = billDAO.update("insert into bill value(null,?,?,?,?,?,now(),'未结账')",
billId, menuId, nums, menuService.getMenuById(menuId).getPrice() * nums, diningTableId);
//3.做一个判断
if (update<=0){
return false;
}
//2.需要更新对应餐桌的状态
return diningTableService.updateDiningTableState(diningTableId,"q就餐中");
}
//返回所有的账单,提供给View使用
public List<Bill> list(){
return billDAO.queryMulti("select * from bill",Bill.class);
}
//结账功能的思路:
//1. 对餐桌号进行校验
//2. 修改bill表的state
//3. 修改diningTable信息
//1. 对餐桌号进行校验
//查看某个餐桌是否有未结账的账单
public boolean hasPayBillByDiningTable(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,失败则返回false
public boolean payBill(int diningTableId,String payMode){
//这里也可以用事物来解决
//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
//2. 修改bill表的state
int update = billDAO.update("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;
}
//3. 修改diningTable信息
//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;
}
//如果上面两项都成功,则返回true
return true;
}
}
package com.song.mhl.view;
import com.song.mhl.domain.Bill;
import com.song.mhl.domain.DiningTable;
import com.song.mhl.domain.Employee;
import com.song.mhl.domain.Menu;
import com.song.mhl.service.BillService;
import com.song.mhl.service.DiningTableService;
import com.song.mhl.service.EmployeeService;
import com.song.mhl.service.MenuService;
import com.song.mhl.utils.Utility;
import java.util.List;
public class MLHView {
//控制是否退出菜单
private boolean loop = true;
//接收用户选择
private String key = "";
//定义EmployeeService属性
private EmployeeService employeeService = new EmployeeService();
//定义一个DiningTableService属性
private DiningTableService diningTableService = new DiningTableService();
//定义一个MenuService属性
private MenuService menuService = new MenuService();
//定义BillService属性
private BillService billService = new BillService();
public static void main(String[] args) {
new MLHView().mainMenu();
}
//定义二级菜单方法,进行封装
//1.显示所有餐桌的状态
//写在一个方法里面进行封装
public void listDiningTable() {
List<DiningTable> list = diningTableService.list();
System.out.println("\n餐桌编号\t\t餐桌编号");
for (DiningTable diningTable : list) {
System.out.println(diningTable);
}
System.out.println("=================显示完毕=================");
}
//2.完成订座
public void orderDiningTable() {
System.out.println("=================预订餐桌=================");
System.out.println("请选择要预定餐桌编号(-1退出):");
int orderId = Utility.readInt();
if (orderId == -1) {
System.out.println("=================取消预定=================");
return;
}
//该方法得到的是 Y 或者 N
char key = Utility.readConfirmSelection();
if (key == 'Y') {//要预定
//根据orderId返回DiningTable对象,如果为null,说明该对象不存在
DiningTable diningTableById = diningTableService.getDiningTableById(orderId);
if (diningTableById == null) {
System.out.println("==============预订餐桌不存在==============");
return;
}
//如果DiningTable对象不为null,那么判断餐桌的状态是否为"空"
if (!("空".equals(diningTableById.getState()))) {//取反
System.out.println("==============餐桌已经被预定==============");
return;
}
//如果上述两种情况都不存在,则可以进行预定
//1.接收预定信息
System.out.println("预订人名字:");
String orderName = Utility.readString(32);
System.out.println("预订人电话:");
String orderTel = Utility.readString(32);
//2.更新餐桌状态
if (diningTableService.orderDiningTable(orderId, "已经预定", orderName, orderTel)) {
System.out.println("=================预订成功=================");
} else {
System.out.println("=================预订失败=================");
}
} else {
System.out.println("=================取消预定=================");
}
}
//3.显示所有菜品
public void listMenu() {
System.out.println("显示所有菜品");
System.out.println("\n菜品编号\t\t菜品名\t\t类别\t\t价格");
List<Menu> list = menuService.list();
for (Menu menu : list) {
System.out.println(menu);
}
}
//4.完成点餐
public void orderMenu() {
System.out.println("=================点餐服务=================");
System.out.println("请选择点餐的桌号(-1退出):");
int orderDiningTableId = Utility.readInt();
if (orderDiningTableId == -1) {
System.out.println("=================取消点餐=================");
return;
}
System.out.println("请选择菜品的编号(-1退出):");
int orderMenuId = Utility.readInt();
if (orderMenuId == -1) {
System.out.println("=================取消点餐=================");
return;
}
System.out.println("请选择菜品的数量(-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 diningTableById = diningTableService.getDiningTableById(orderDiningTableId);
if (diningTableById == null) {
System.out.println("===============餐桌号不存在===============");
return;
}
//验证菜品编号
Menu menu = menuService.getMenuById(orderMenuId);
if (menu == null) {
System.out.println("===============菜品号不存在===============");
return;
}
//进行点餐
//该方法得到的是 Y 或者 N
char key = Utility.readConfirmSelection2();
if (key == 'Y') {
billService.orderMenu(orderMenuId, orderNums, orderDiningTableId);
System.out.println("=================点餐成功=================");
} else if (key == 'N') {
System.out.println("=================取消点餐=================");
return;
} else {
System.out.println("=================点餐失败=================");
}
}
//5.显示账单信息
public void listBill() {
System.out.println("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状态");
List<Bill> list = billService.list();
for (Bill bill : list) {
System.out.println(bill);
}
System.out.println("=================显示完毕=================");
}
//6.结账
public void payBill() {
System.out.println("=================结账服务=================");
System.out.println("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 diningTableById = diningTableService.getDiningTableById(diningTableId);
if (diningTableById == null) {
System.out.println("=============结账的餐桌不存在=============");
return;
}
//验证是否有未结账的餐桌
if (!billService.hasPayBillByDiningTable(diningTableId)) {
System.out.println("===========该餐位没有未结账账单===========");
return;
}
//如果上述两个都过了,说明存在未结账的账单
System.out.println("结账的方式(现金/支付宝/微信)回车表示退出");
//Utility.readString(10,"")里的""代表如果回车,则表示空串
String payMode = Utility.readString(10, "");
//限定结账方式,不能输入别的
if (!("现金".equals(payMode)||"支付宝".equals(payMode)||"微信".equals(payMode)||"".equals(payMode))){
System.out.println("=================结账失败=================");
return;
}
if ("".equals(payMode)) {
System.out.println("=================取消结账=================");
return;
}
//进行选择 确认是否结账(Y/N):
//该方法得到的是 Y 或者 N
char key = Utility.readConfirmSelection3();
if (key == 'Y') {
//调用billService中的完成结账方法
if (billService.payBill(diningTableId, payMode)) {
System.out.println("=================结账完成=================");
} else {
System.out.println("=================结账失败=================");
}
} else if (key == 'N') {
System.out.println("=================取消结账=================");
} else {
System.out.println("=================结账失败=================");
}
}
//显示主菜单
public void mainMenu() {
while (loop) {
System.out.println("===================满汉楼===================");
System.out.println("\t\t\t 1 登录满汉楼");
System.out.println("\t\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.println("请输入员工号:");
String empid = Utility.readString(32);
System.out.println("请输入密 码:");
String pwd = Utility.readString(32);
//到数据库来验证
Employee employee = employeeService.getEmployeeByIdAndPwd(empid, pwd);
if (employee != null) {
System.out.println("==================登录成功==================");
//显示二级菜单,这里二级菜单也是循环,用while
while (loop) {
System.out.println("===============满汉楼二级菜单===============");
System.out.println("\t\t\t 1 显示餐桌状态");
System.out.println("\t\t\t 2 预定餐桌");
System.out.println("\t\t\t 3 显示所有菜品");
System.out.println("\t\t\t 4 点餐服务");
System.out.println("\t\t\t 5 查看账单");
System.out.println("\t\t\t 6 结账");
System.out.println("\t\t\t 9 退出满汉楼");
System.out.println("请输入你的选择:");
String key = Utility.readString(1);
switch (key) {
case "1":
System.out.println("显示餐桌状态");
//将下面的代码封装到一个方法里面
//增强代码的阅读性和可维护性
listDiningTable();
/*
//查询表格
//餐桌状态 餐桌编号
List list = diningTableService.list();
System.out.println("\n餐桌编号\t\t餐桌编号");
for (DiningTable diningTable:list) {
System.out.println(diningTable);
}
System.out.println("=================显示完毕=================");
*/
break;
case "2":
orderDiningTable();
break;
case "3":
listMenu();
//菜品编号 菜品名 类别 价格
//查询数据库表格
break;
case "4":
orderMenu();
break;
case "5":
listBill();
//编号 菜品号 菜品量 金额 桌号 日期 状态
//查询数据库表格
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!");
}
}
System.out.println("退出满汉楼");
} else {
System.out.println("==================登录失败==================");
}
break;
case "2":
loop = false;
break;
default:
System.out.println("输入有误,请重新输入!");
}
}
System.out.println("退出满汉楼");
}
}
如果查看账单时,希望显示菜品名称,怎么办呢?
处理方式一:
单独创建一个MultiTableBean类
package com.song.mhl.domain;
import com.song.mhl.service.DiningTableService;
import com.song.mhl.service.MenuService;
import java.util.Date;
/**
* 这是一个Javabean 可以和多张表进行对应
*/
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
private String name;
//定义一个DiningTableService属性
private DiningTableService diningTableService = new DiningTableService();
//定义一个MenuService属性
private MenuService menuService = new MenuService();
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 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;
}
//给name生成一个setter和getter方法
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return id +
"\t\t\t" + menuId +
"\t\t\t" + nums +
"\t\t\t" + money +
"\t\t" + diningTableId +
"\t\t\t" + billDate +
"\t\t" + state +
"\t\t" + name;
}
}
这个类的属性来自于mysql里面多张表的字段
然后创建子类MultiTableDAO继承父类BasicDAO
package com.song.mhl.dao;
import com.song.mhl.domain.MultiTableBean;
public class MultiTableDAO extends BasicDAO<MultiTableBean>{
}
提供给业务层使用,完成某个具体的业务需求
//定义一个MultiTableDAO
private MultiTableDAO multiTableDAO = new MultiTableDAO();
//返回所有的账单并带有菜品,提供给View使用
public List<MultiTableBean> list2(){
return multiTableDAO.queryMulti
("SELECT bill.*,NAME FROM bill,menu WHERE bill.id = menu.id",MultiTableBean.class);
}
最后在界面层使用
public void listBill() {
/*
System.out.println("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状态");
List list = billService.list();
for (Bill bill : list) {
System.out.println(bill);
}
*/
//用于多表查询
System.out.println("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状态\t\t菜品名");
List<MultiTableBean> list = billService.list2();
for (MultiTableBean multiTableBean : list) {
System.out.println(multiTableBean);
}
System.out.println("=================显示完毕=================");
}
下图所示
处理方式二:
思考:完成更多功能,登录管理、人事管理、统计报表、成本控制