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程序框架图
代码实现
数据库
-- 创立满汉楼的数据库
CREATE DATABASE mhl
-- 创立表 employee 表 (主键 id, empId, name, pwd, job, 如果须要能够本人加字段等)
#用户表
CREATE TABLE employee (
id INT PRIMARY KEY AUTO_INCREMENT, #自增
empId VARCHAR(50) UNIQUE NOT NULL DEFAULT '',# 员工号
pwd CHAR(32) NOT NULL DEFAULT '',# 明码 md5
NAME VARCHAR(50) NOT NULL DEFAULT '',# 姓名
job VARCHAR(50) NOT NULL DEFAULT '' #岗位
)CHARSET=utf8;
DROP TABLE employee
#增加测试数据
INSERT INTO employee VALUES(NULL, '6668612', MD5('123456'), '张三丰', '经理');
INSERT INTO employee VALUES(NULL, '6668622', MD5('123456'),'小龙女', '服务员');
INSERT INTO employee VALUES(NULL, '6668633', MD5('123456'), '张无忌', '收银员');
INSERT INTO employee VALUES(NULL, '666666', MD5('123456'), '老韩', '经理');
SELECT * FROM employee;
SELECT * FROM employee WHERE empId='666666' AND pwd=MD5('123456')
-- 创立 diningTable 表(id, state , orderName, orderTel ....)
CREATE TABLE diningTable (
id INT PRIMARY KEY AUTO_INCREMENT, #自增, 示意餐桌编号
state VARCHAR(20) NOT NULL DEFAULT '',# 餐桌的状态
orderName VARCHAR(50) NOT NULL DEFAULT '',# 预订人的名字
orderTel VARCHAR(20) NOT NULL DEFAULT ''
)CHARSET=utf8;
#测试数据
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
INSERT INTO diningTable VALUES(NULL, '空','','');
SELECT * FROM diningTable
SELECT * FROM diningTable
SELECT * FROM diningTable WHERE id = 1
UPDATE diningTable SET state='空', orderName='', orderTel='' WHERE id=1
-- 创立 menu 表(id, name, type, price)
#菜谱
CREATE TABLE menu (id INT PRIMARY KEY AUTO_INCREMENT, #自增主键，作为菜谱编号(惟一)
NAME VARCHAR(50) NOT NULL DEFAULT '',# 菜品名称
TYPE VARCHAR(50) NOT NULL DEFAULT '', #菜品品种
price DOUBLE NOT NULL DEFAULT 0# 价格
)CHARSET=utf8;
#测试数据
INSERT INTO menu VALUES(NULL, '八宝饭', '主食', 10);
INSERT INTO menu VALUES(NULL, '叉烧包', '主食', 20);
INSERT INTO menu VALUES(NULL, '宫保鸡丁', '热菜', 30);
INSERT INTO menu VALUES(NULL, '山药拨鱼', '凉菜', 14);
INSERT INTO menu VALUES(NULL, '银丝卷', '甜食', 9);
INSERT INTO menu VALUES(NULL, '水煮鱼', '热菜', 26);
INSERT INTO menu VALUES(NULL, '甲鱼汤', '汤类', 100);
INSERT INTO menu VALUES(NULL, '鸡蛋汤', '汤类', 16);
SELECT * FROM menu;
#同学们能够独自创立一张表，示意菜品的类别
#减少表 bill 账单表(id, billId, menuId, nums, billDate, money, state, diningTableId)
#账单流水, 思考能够离开结账, 并思考未来别离统计各个不同菜品的销售状况
CREATE TABLE bill (
id INT PRIMARY KEY AUTO_INCREMENT, #自增主键
billId VARCHAR(50) NOT NULL DEFAULT '',# 账单号能够依照本人规定生成 UUID
menuId INT NOT NULL DEFAULT 0,# 菜品的编号, 也能够应用外键
nums INT NOT NULL DEFAULT 0,# 份数
money DOUBLE NOT NULL DEFAULT 0, #金额
diningTableId INT NOT NULL DEFAULT 0, #餐桌
billDate DATETIME NOT NULL ,# 订单日期
state VARCHAR(50) NOT NULL DEFAULT ''# 状态' 未结账 ',' 曾经结账 ',' 挂单 ',' 现金 ',' 支付宝 ',' 坏账 '
)CHARSET=utf8;
SELECT * FROM bill;
select * from bill
SELECT * FROM menu WHERE id = 1
UPDATE diningTable SET state=? WHERE id=?
SELECT * FROM diningTable
-- 查出某个餐桌是否有未结账的账单
select * from bill where diningTableId=1 and state = '未结账' limit 0, 1Java
`-- src
|-- com
| `-- hspedu
| `-- mhl
| |-- dao
| | |-- BasicDAO.java
| | |-- BillDAO.java
| | |-- DiningTableDAO.java
| | |-- EmployeeDAO.java
| | |-- MenuDAO.java
| | `-- MultiTableDAO.java
| |-- domain
| | |-- Bill.java
| | |-- DiningTable.java
| | |-- Employee.java
| | |-- Menu.java
| | `-- MultiTableBean.java
| |-- service
| | |-- BillService.java
| | |-- DiningTableService.java
| | |-- EmployeeService.java
| | `-- MenuService.java
| |-- utils
| | |-- JDBCUtilsByDruid.java
| | `-- Utility.java
| `-- view
| `-- MHLView.java
`-- druid.propertiessrc/com/hspedu/mhl/dao/BasicDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.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 , 是其余 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 办法, 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) {throw new RuntimeException(e); // 将编译异样 -> 运行异样 , 抛出
} finally {JDBCUtilsByDruid.close(null, null, connection);
}
}
// 返回多个对象(即查问的后果是多行), 针对任意表
/**
*
* @param sql sql 语句，能够有 ?
* @param clazz 传入一个类的 Class 对象 比方 Actor.class
* @param parameters 传入 ? 的具体的值，能够是多个
* @return 依据 Actor.class 返回对应的 ArrayList 汇合
*/
public List<T> queryMulti(String sql, Class<T> clazz, Object... parameters) {
Connection connection = null;
try {connection = JDBCUtilsByDruid.getConnection();
return qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);
} catch (SQLException e) {throw new RuntimeException(e); // 将编译异样 -> 运行异样 , 抛出
} finally {JDBCUtilsByDruid.close(null, null, connection);
}
}
// 查问单行后果 的通用办法
public T querySingle(String sql, Class<T> clazz, Object... parameters) {
Connection connection = null;
try {connection = JDBCUtilsByDruid.getConnection();
return qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);
} catch (SQLException e) {throw new RuntimeException(e); // 将编译异样 -> 运行异样 , 抛出
} finally {JDBCUtilsByDruid.close(null, null, connection);
}
}
// 查问单行单列的办法, 即返回单值的办法
public Object queryScalar(String sql, Object... parameters) {
Connection connection = null;
try {connection = JDBCUtilsByDruid.getConnection();
return qr.query(connection, sql, new ScalarHandler(), parameters);
} catch (SQLException e) {throw new RuntimeException(e); // 将编译异样 -> 运行异样 , 抛出
} finally {JDBCUtilsByDruid.close(null, null, connection);
}
}
}src/com/hspedu/mhl/dao/BillDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.mhl.domain.Bill;
public class BillDAO extends BasicDAO<Bill> {}src/com/hspedu/mhl/dao/DiningTableDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.mhl.domain.DiningTable;
public class DiningTableDAO extends BasicDAO<DiningTable> {// 如果有特地的操作，能够写在 DiningTableDAO}src/com/hspedu/mhl/dao/EmployeeDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.mhl.domain.Employee;
public class EmployeeDAO extends BasicDAO<Employee> {// 这里还能够写特有的操作.}src/com/hspedu/mhl/dao/MenuDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.mhl.domain.Menu;
public class MenuDAO extends BasicDAO<Menu> {}src/com/hspedu/mhl/dao/MultiTableDAO.java
package com.hspedu.mhl.dao;
import com.hspedu.mhl.domain.MultiTableBean;
public class MultiTableDAO extends BasicDAO<MultiTableBean> {}src/com/hspedu/mhl/domain/Bill.java
package com.hspedu.mhl.domain;
import java.util.Date;
/**
* Bill 是 javabean 和 bill 对应
* id int primary key auto_increment, #自增主键
* billId varchar(50) not null default '',# 账单号能够依照本人规定生成 UUID
* menuId int not null default 0,# 菜品的编号, 也能够应用外键
* nums int not null default 0,# 份数
* money double not null default 0, #金额
* diningTableId int not null default 0, #餐桌
* billDate datetime not null ,# 订单日期
* state varchar(50) not null default ''# 状态' 未结账 ',' 曾经结账 ',' 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 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" + menuId +
"\t\t\t" + nums +
"\t\t\t" + money +
"\t" + diningTableId +
"\t\t" + billDate +
"\t\t" + state ;
}
}src/com/hspedu/mhl/domain/DiningTable.java
package com.hspedu.mhl.domain;
/**
* 这是一个 javabean 和 diningTable 表对应
* id int primary key auto_increment, #自增, 示意餐桌编号
* 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;}
@Override
public String toString() {return id + "\t\t\t" + state;}
}src/com/hspedu/mhl/domain/Employee.java
package com.hspedu.mhl.domain;
/**
* 这是一个 javabean 和 employee 对应
* id int primary key auto_increment, #自增
* empId varchar(50) not null default '',# 员工号
* pwd char(32) not null default '',# 明码 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() { // 无参结构器，底层 apache-dbutils 反射须要}
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;}
}src/com/hspedu/mhl/domain/Menu.java
package com.hspedu.mhl.domain;
/**
* 该类 (javabean) 和 menu 表对应
* id int primary key auto_increment, #自增主键，作为菜谱编号(惟一)
* name varchar(50) not null default '',# 菜品名称
* type varchar(50) not null default '', #菜品品种
* 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() {// 无参结构器}
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;}
}src/com/hspedu/mhl/domain/MultiTableBean.java
package com.hspedu.mhl.domain;
import java.util.Date;
/**
* 这是一个 javabean 能够和多张表进行对应
*/
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;
// 减少一个来自 menu 表的列 name
// 思考 这里的属性名是否肯定要和表的列名保持一致.
// 答: 能够不统一，然而须要 sql 做相应的批改, 标准须要保持一致（例如 SELECT Name AS name2 他会调用对应的 setName2 构造方法）.
private String name;
// 减少来自 menu 表的列 price
private Double price;// 默认值 nulll
// 实际上是调用无参结构器，进行反射调用，而后通过 setter 和 getter 办法进行调用的：public MultiTableBean() {System.out.println("反射调用....");
}
// public MultiTableBean(Integer id, String billId, Integer menuId, Integer nums, Double money, Integer diningTableId, Date billDate, String state, String name, Double price) {
// this.id = id;
// this.billId = billId;
// this.menuId = menuId;
// this.nums = nums;
// this.money = money;
// this.diningTableId = diningTableId;
// this.billDate = billDate;
// this.state = state;
// this.name = name;
// this.price = price;
// }
// 给 price 生成 setter 和 getter
public Double getPrice() {return price;}
public void setPrice(Double price) {this.price = price;}
// 给 name 生成 setter 和 getter
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 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" + menuId +
"\t\t\t" + nums +
"\t\t\t" + money +
"\t" + diningTableId +
"\t\t" + billDate +
"\t\t" + state +
"\t\t" + name +
"\t\t" + price;
}
}src/com/hspedu/mhl/service/BillService.java
package com.hspedu.mhl.service;
import com.hspedu.mhl.dao.BillDAO;
import com.hspedu.mhl.dao.MultiTableDAO;
import com.hspedu.mhl.domain.Bill;
import com.hspedu.mhl.domain.MultiTableBean;
import java.util.List;
import java.util.UUID;
/**
* 解决和账单相干的业务逻辑
*/
public class BillService {
// 定义 BillDAO 属性
private BillDAO billDAO = new BillDAO();
// 定义 MenuService 属性
private MenuService menuService = new MenuService();
// 定义 DiningTableService 属性
private DiningTableService diningTableService = new DiningTableService();
private MultiTableDAO multiTableDAO = new MultiTableDAO();
// 思考
// 编写点餐的办法
//1. 生成账单
//2. 须要更新对应餐桌的状态
//3. 如果胜利返回 true, 否则返回 false
public boolean orderMenu(int menuId, int nums, int diningTableId) {
// 生成一个账单号,UUID
String billID = UUID.randomUUID().toString();
// 将账单生成到 bill 表, 要求间接计算账单金额
int update = billDAO.update("insert into bill values(null,?,?,?,?,?,now(),' 未结账 ')",
billID, menuId, nums, menuService.getMenuById(menuId).getPrice() * nums, diningTableId);
if (update <= 0) {return false;}
// 须要更新对应餐桌的状态
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.queryMulti("select * from bill", Bill.class);
}
// 返回所有的账单并带有菜品名, 价格，提供给 View 调用
public List<MultiTableBean> list2() {
return multiTableDAO.queryMulti("SELECT bill.*, NAME" +
"FROM bill, menu" +
"WHERE bill.menuId = menu.id", MultiTableBean.class);
}
// 查看某个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;
}
// 实现结账[如果餐桌存在，并且该餐桌有未结账的账单]
// 如果胜利，返回 true, 失败返回 false
public boolean payBill(int diningTableId, String payMode) {
// 如果这里应用事务的话，须要用 ThreadLocal 来解决 , 框架中比方 mybatis 提供了事务反对
//1. 批改 bill 表
int update = billDAO.update("update bill set state=? where diningTableId=? and state=' 未结账 '", payMode, diningTableId);
if(update <= 0) { // 如果更新没有胜利，则示意失败...
return false;
}
//2. 批改 diningTable 表
// 留神：不要间接在这里操作，而应该调用 DiningTableService 办法, 实现更新，体现各司其职
if(!diningTableService.updateDiningTableToFree(diningTableId, "空")) {return false;}
return true;
}
}src/com/hspedu/mhl/service/DiningTableService.java
package com.hspedu.mhl.service;
import com.hspedu.mhl.dao.DiningTableDAO;
import com.hspedu.mhl.domain.DiningTable;
import java.util.List;
public class DiningTableService { // 业务层
// 定义一个 DiningTableDAO 对象
private DiningTableDAO diningTableDAO = new DiningTableDAO();
// 返回所有餐桌的信息
public List<DiningTable> list() {return diningTableDAO.queryMulti("select id, state from diningTable", DiningTable.class);
}
// 依据 id , 查问对应的餐桌 DiningTable 对象
//, 如果返回 null , 示意 id 编号对应的餐桌不存在
public DiningTable getDiningTableById(int id) {
// 小技巧：把 sql 语句放在查问分析器去测试一下.
return diningTableDAO.querySingle("select * from diningTable where id = ?", DiningTable.class, id);
}
// 如果餐桌能够预约，调用办法，对其状态进行更新(包含预约人的名字和电话)
public boolean orderDiningTable(int id, String orderName, String orderTel) {
int update =
diningTableDAO.update("update diningTable set state=' 曾经预约 ', orderName=?, orderTel=? where id=?", orderName, orderTel, id);
return update > 0;
}
// 须要提供一个更新 餐桌状态的办法
public boolean updateDiningTableState(int id, String state) {int update = diningTableDAO.update("update diningTable set state=? where id=?", state, id);
return update > 0;
}
// 提供办法，将指定的餐桌设置为闲暇状态
public boolean updateDiningTableToFree(int id, String state) {int update = diningTableDAO.update("update diningTable set state=?,orderName='',orderTel=''where id=?", state, id);
return update > 0;
}
}src/com/hspedu/mhl/service/EmployeeService.java
package com.hspedu.mhl.service;
import com.hspedu.mhl.dao.EmployeeDAO;
import com.hspedu.mhl.domain.Employee;
/**
* 该类实现对 employee 表的各种操作(通过调用 EmployeeDAO 对象实现)
*/
public class EmployeeService {
// 定义一个 EmployeeDAO 属性
private EmployeeDAO employeeDAO = new EmployeeDAO();
// 办法，依据 empId 和 pwd 返回一个 Employee 对象
// 如果查问不到，就返回 null
public Employee getEmployeeByIdAndPwd(String empId, String pwd) {return employeeDAO.querySingle("select * from employee where empId=? and pwd=md5(?)", Employee.class, empId, pwd);
}
}src/com/hspedu/mhl/service/MenuService.java
package com.hspedu.mhl.service;
import com.hspedu.mhl.dao.MenuDAO;
import com.hspedu.mhl.domain.Menu;
import java.util.List;
/**
* 实现对 menu 表的各种操作(通过调用 MenuDAO)
*/
public class MenuService {
// 定义 MenuDAO 属性
private MenuDAO menuDAO = new MenuDAO();
// 返回所有的菜品, 返回给界面应用
public List<Menu> list() {return menuDAO.queryMulti("select * from menu", Menu.class);
}
// 须要办法，依据 id, 返回 Menu 对象
public Menu getMenuById(int id) {return menuDAO.querySingle("select * from menu where id = ?", Menu.class, id);
}
}src/com/hspedu/mhl/utils/JDBCUtilsByDruid.java
package com.hspedu.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;
// 在动态代码块实现 ds 初始化
static {Properties properties = new Properties();
try {properties.load(new FileInputStream("src\\druid.properties"));
ds = DruidDataSourceFactory.createDataSource(properties);
} catch (Exception e) {e.printStackTrace();
}
}
// 编写 getConnection 办法
public static Connection getConnection() throws SQLException {return ds.getConnection();
}
// 敞开连贯, 老师再次强调：在数据库连接池技术中，close 不是真的断掉连贯
// 而是把应用的 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);
}
}
}src/com/hspedu/mhl/utils/Utility.java
package com.hspedu.mhl.utils;
/**
工具类的作用:
解决各种状况的用户输出，并且可能依照程序员的需要，失去用户的控制台输出。*/
import java.util.*;
/**
*/
public class Utility {
// 动态属性。。。private static Scanner scanner = new Scanner(System.in);
/**
* 性能：读取键盘输入的一个菜单选项，值：1——5 的范畴
* @return 1——5
*/
public static char readMenuSelection() {
char c;
for (; ;) {String str = readKeyBoard(1, false);// 蕴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("抉择谬误，请从新输出：");
} else break;
}
return c;
}
/**
* 性能：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);
}
/**
* 性能：读取键盘输入的一个字符，如果间接按回车，则返回指定的默认值；否则返回输出的那个字符
* @param defaultValue 指定的默认值
* @return 默认值或输出的字符
*/
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);
}
/**
* 性能：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("数字输出谬误，请从新输出：");
}
}
return n;
}
/**
* 性能：读取键盘输入的 整数或默认值，如果间接回车，则返回默认值，否则返回输出的整数
* @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;}
// 异样解决...
try {n = Integer.parseInt(str);
break;
} catch (NumberFormatException e) {System.out.print("数字输出谬误，请从新输出：");
}
}
return n;
}
/**
* 性能：读取键盘输入的指定长度的字符串
* @param limit 限度的长度
* @return 指定长度的字符串
*/
public static String readString(int limit) {return readKeyBoard(limit, false);
}
/**
* 性能：读取键盘输入的指定长度的字符串或默认值，如果间接回车，返回默认值，否则返回字符串
* @param limit 限度的长度
* @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;
}
/**
* 性能：读取键盘输入的确认选项，Y 或 N
* 将小的性能，封装到一个办法中.
* @return Y 或 N
*/
public static char readConfirmSelection() {System.out.print("确认是否预订(Y/N):");
char c;
for (; ;) {// 有限循环
// 在这里，将承受到字符，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("抉择谬误，请从新输出：");
}
}
return c;
}
/**
* 性能：读取一个字符串
* @param limit 读取的长度
* @param blankReturn 如果为 true , 示意 能够读空字符串。* 如果为 false 示意 不能读空字符串。*
* 如果输出为空，或者输出大于 limit 的长度，就会提醒从新输出。* @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, 即用户没有输出任何内容，间接回车
if (line.length() == 0) {if (blankReturn) return line;// 如果 blankReturn=true, 能够返回空串
else continue; // 如果 blankReturn=false, 不承受空串，必须输出内容
}
// 如果用户输出的内容大于了 limit，就提醒重写输出
// 如果用户如的内容 >0 <= limit , 我就承受
if (line.length() < 1 || line.length() > limit) {System.out.print("输出长度（不能大于" + limit + "）谬误，请从新输出：");
continue;
}
break;
}
return line;
}
}src/com/hspedu/mhl/view/MHLView.java
package com.hspedu.mhl.view;
import com.hspedu.mhl.domain.*;
import com.hspedu.mhl.service.BillService;
import com.hspedu.mhl.service.DiningTableService;
import com.hspedu.mhl.service.EmployeeService;
import com.hspedu.mhl.service.MenuService;
import com.hspedu.mhl.utils.Utility;
import java.util.List;
import java.util.UUID;
/**
* 这是主界面
*/
public class MHLView {
// 管制是否退出菜单
private boolean loop = true;
private String key = ""; // 接管用户的抉择
// 定义 EmployeeService 属性
private EmployeeService employeeService = new EmployeeService();
// 定义 DiningTableService 的属性
private DiningTableService diningTableService = new DiningTableService();
// 定义 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 MHLView().mainMenu();}
// 实现结账
public void payBill() {System.out.println("============== 结账服务 ============");
System.out.print("请抉择要结账的餐桌编号(- 1 退出):");
int diningTableId = Utility.readInt();
if (diningTableId == -1) {System.out.println("============= 勾销结账 ============");
return;
}
// 验证餐桌是否存在
DiningTable diningTable = diningTableService.getDiningTableById(diningTableId);
if (diningTable == null) {System.out.println("============= 结账的餐桌不存在 ============");
return;
}
// 验证餐桌是否有须要结账的账单
if (!billService.hasPayBillByDiningTableId(diningTableId)) {System.out.println("============= 该餐位没有未结账账单 ============");
return;
}
System.out.print("结账形式 (现金 / 支付宝 / 微信) 回车示意退出:");
String payMode = Utility.readString(20, "");// 阐明如果回车，就是返回""
if ("".equals(payMode)) {System.out.println("============= 勾销结账 ============");
return;
}
char key = Utility.readConfirmSelection();
if (key == 'Y') { // 结账
// 调用咱们写的办法
if (billService.payBill(diningTableId, payMode)) {System.out.println("============= 实现结账 ============");
} else {System.out.println("============= 结账失败 ============");
}
} else {System.out.println("============= 勾销结账 ============");
}
}
// 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("============== 显示结束 ============");
List<MultiTableBean> multiTableBeans = billService.list2();
System.out.println("\n 编号 \t\t 菜品号 \t\t 菜品量 \t\t 金额 \t\t 桌号 \t\t 日期 \t\t\t\t\t\t\t 状态 \t\t 菜品名 \t\t 价格");
for (MultiTableBean bill : multiTableBeans) {System.out.println(bill);
}
System.out.println("============== 显示结束 ============");
}
// 实现点餐
public void orderMenu() {System.out.println("============== 点餐服务 ============");
System.out.print("请输出点餐的桌号(- 1 退出):");
int orderDiningTableId = Utility.readInt();
if (orderDiningTableId == -1) {System.out.println("============== 勾销点餐 ============");
return;
}
System.out.print("请输出点餐的菜品号(- 1 退出):");
int orderMenuId = Utility.readInt();
if (orderMenuId == -1) {System.out.println("============== 勾销点餐 ============");
return;
}
System.out.print("请输出点餐的菜品量(- 1 退出):");
int orderNums = Utility.readInt();
if (orderNums == -1) {System.out.println("============== 勾销点餐 ============");
return;
}
// 验证餐桌号是否存在.
DiningTable diningTable = diningTableService.getDiningTableById(orderDiningTableId);
if (diningTable == null) {System.out.println("============== 餐桌号不存在 ============");
return;
}
// 验证菜品编号
Menu menu = menuService.getMenuById(orderMenuId);
if (menu == null) {System.out.println("============== 菜品号不存在 ============");
return;
}
// 点餐
if (billService.orderMenu(orderMenuId, orderNums, orderDiningTableId)) {System.out.println("============== 点餐胜利 ============");
} else {System.out.println("============== 点餐失败 ============");
}
}
// 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 价格");
for (Menu menu : list) {System.out.println(menu);
}
System.out.println("============== 显示结束 ============");
}
// 实现订座
public void orderDiningTable() {System.out.println("============== 预约餐桌 ============");
System.out.print("请抉择要预约的餐桌编号(- 1 退出):");
int orderId = Utility.readInt();
if (orderId == -1) {System.out.println("============== 勾销预订餐桌 ============");
return;
}
// 该办法失去的是 Y 或者 N
char key = Utility.readConfirmSelection();
if (key == 'Y') {// 要预约
// 依据 orderId 返回 对应 DiningTable 对象, 如果为 null, 阐明该对象不存在
DiningTable diningTable = diningTableService.getDiningTableById(orderId);
if (diningTable == null) {//
System.out.println("============== 预订餐桌不存在 ============");
return;
}
// 判断该餐桌的状态是否 "空"
if (!("空".equals(diningTable.getState()))) {// 阐明以后这个餐桌不是 "空" 状态
System.out.println("============== 该餐桌曾经预约或者就餐中 ============");
return;
}
// 接管预约信息
System.out.print("预约人的名字:");
String orderName = Utility.readString(50);
System.out.print("预约人的电话:");
String orderTel = Utility.readString(50);
// 更新餐桌状态
if (diningTableService.orderDiningTable(orderId, orderName, orderTel)) {System.out.println("============== 预订餐桌胜利 ============");
} else {System.out.println("============== 预订餐桌失败 ============");
}
} else {System.out.println("============== 勾销预订餐桌 ============");
}
}
// 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("============== 显示结束 ============");
}
// 显示主菜单
public void mainMenu() {while (loop) {System.out.println("\n=============== 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.print("请输出你的抉择:");
key = Utility.readString(1);
switch (key) {
case "1":
System.out.print("输出员工号:");
String empId = Utility.readString(50);
System.out.print("输出密 码:");
String pwd = Utility.readString(50);
Employee employee = employeeService.getEmployeeByIdAndPwd(empId, pwd);
if (employee != null) { // 阐明存在该用户
System.out.println("=============== 登录胜利[" + employee.getName() + "]================\n");
// 显示二级菜单, 这里二级菜单是循环操作，所以做成 while
while (loop) {System.out.println("\n=============== 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 预约餐桌");
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.print("请输出你的抉择:");
key = Utility.readString(1);
switch (key) {
case "1":
listDiningTable();// 显示餐桌状态
break;
case "2":
orderDiningTable();
break;
case "3":
listMenu();
break;
case "4":
orderMenu();
break;
case "5":
listBill();// 显示所有账单
break;
case "6":
payBill();
break;
case "9":
loop = false;
break;
default:
System.out.println("你的输出有误，请从新输出");
break;
}
}
} else {System.out.println("=============== 登录失败 ================");
}
break;
case "2":
loop = false;//
break;
default:
System.out.println("你输出有误，请从新输出.");
}
}
System.out.println("你退出了满汉楼零碎~");
}
}src/druid.properties
#key=value
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mhl?rewriteBatchedStatements=true
username=root
password=hsp
#initial connection Size
initialSize=10
#min idle connecton size
minIdle=5
#max active connection size
maxActive=50
#max wait time (5000 mil seconds)
maxWait=5000mhl.iml
<?xml version="1.0" encoding="UTF-8"?>
<module type="JAVA_MODULE" version="4">
<component name="NewModuleRootManager" inherit-compiler-output="true">
<exclude-output />
<content url="file://$MODULE_DIR$">
<sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
</content>
<orderEntry type="inheritedJdk" />
<orderEntry type="sourceFolder" forTests="false" />
<orderEntry type="library" name="commons-dbutils-1.3" level="project" />
</component>
</module>多表查问思路
能够用 MapListHandler 实现：
https://www.pianshen.com/article/48341042440/
也能够另写 MultiTabBean 类，映射多个表，如上所示。
正文完