餐桌预定
思路分析
在 DiningTableService 中编写相应的方法完成如下要求，并在 View 中加入相关的业务逻辑
餐桌预定需要满足两个条件
（1）预定的餐桌编号存在
（2）餐桌状态为空
DiningTableService
java
package service;
import dao.DiningTableDao;
import domain.DiningTable;
import utils.Utility;
import java.util.List;
/**
* ClassName: DiningTableService
* Package: service
* Description:
*
* @author jacksonling
* @version 1.0
* @Date 2025-08-06 16:21
*/
public class DiningTableService {
// 创建 Dao 对象
private DiningTableDao diningTableDao = new DiningTableDao();
// 编写方法，返回所有餐桌状态并显示
public void listDiningTale(){
List<DiningTable> diningTables = diningTableDao.queryTable("select id, state from diningTable", DiningTable.class);
System.out.println("\n餐桌编号\t\t餐桌状态");
for (DiningTable diningTable : diningTables) {
System.out.println(diningTable);
}
System.out.println("==============显示完毕============");
}
/*
餐桌预定的前提条件
（1）预定的餐桌编号存在
（2）餐桌状态为空
*/
// 接收用户输入，根据 id 返回 DiningTable 对象，在界面层判断是否为空进而判断餐桌是否存在
public DiningTable getDiningTableById(int id){
return diningTableDao.queryLine("select * from diningTable where id = ?", DiningTable.class, id);
}
// 如果餐桌可以预定，接收预定信息，更新餐桌状态，返回 boolean，用于判断是否预定成功
public boolean orderDiningTable(int id, String orderName, String orderTel) {
// 返回影响的行数
int update = diningTableDao.update("update diningTable set state='已经预定', orderName=?, orderTel=? where id=?", orderName, orderTel, id);
return update > 0;
}
// 餐桌预定功能
public void orderDiningTable(){
System.out.println("==============预定餐桌============");
System.out.print("请选择要预定的餐桌编号(-1退出): ");
int orderId = Utility.readInt();
if (orderId == -1) {
System.out.println("==============取消预订餐桌============");
return;
}
//该方法得到的是 Y 或者 N
char key = Utility.readConfirmSelection();
if (key == 'Y') {//要预定
// 判断预定的餐桌是否存在
DiningTable diningTable = getDiningTableById(orderId);
if (diningTable == null) {
System.out.println("==============预订餐桌不存在============");
return;
}
// 判断餐桌的状态是否 "空"
if (!("空".equals(diningTable.getState()))) {//说明当前这个餐桌不是 "空" 状态
System.out.println("==============该餐桌已经预定或者就餐中============");
return;
}
//接收预定信息
System.out.print("预定人的名字: ");
String orderName = Utility.readString(50);
System.out.print("预定人的电话: ");
String orderTel = Utility.readString(50);
//更新餐桌状态
if (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============");
}
}
}View
java
package view;
import com.sun.org.apache.bcel.internal.generic.NEW;
import domain.Employee;
import service.DiningTableService;
import service.EmployeeService;
import utils.Utility;
/**
* ClassName: logInView
* Package: view
* Description:
*
* @author jacksonling
* @version 1.0
* @Date 2025-08-06 14:09
*/
public class View {
// 循环结束标志
boolean loop = true;
// 接收用户输入
String key = "";
// 创建 EmployeeService 对象
EmployeeService employeeService = new EmployeeService();
// 创建 diningTableService 对象
DiningTableService diningTableService = new DiningTableService();
//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("请输入你的选择: ");
key = Utility.readString(1);
switch (key) {
case "1":
System.out.print("输入员工号: ");
String empId = Utility.readString(50);
System.out.print("输入密 码: ");
String pwd = Utility.readString(50);
Employee employee = employeeService.getEmployeeByIdAndPwd(empId, pwd);
if (employee != null) { //说明存在该用户
System.out.println("===============登录成功[" + 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 预定餐桌");
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("请输入你的选择: ");
key = Utility.readString(1);
switch (key) {
case "1":
// 显示餐桌状态
diningTableService.listDiningTale();
break;
case "2":
// 预定餐桌
diningTableService.orderDiningTable();
break;
case "3":
// 显示所有菜品
System.out.println("显示所有菜品");
break;
case "4":
// 点餐服务
System.out.println("点餐服务");
break;
case "5":
// 查看账单
System.out.println("查看账单");
break;
case "6":
// 结账
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");
break;
}
}
} else {
System.out.println("=====登录失败（用户名 / 密码错误）=====");
}
break;
case "2":
loop = false;//
break;
default:
System.out.println("你输入有误，请重新输入.");
}
}
System.out.println("退出了满汉楼系统~");
}
}