1.程序框架
package com.stulzl.mhl.view;import com.stulzl.mhl.domain.*;import com.stulzl.mhl.service.BillService;import com.stulzl.mhl.service.DiningTableService;import com.stulzl.mhl.service.EmployeeService;import com.stulzl.mhl.service.MenuService;import com.stulzl.mhl.utils.Utility;import javax.rmi.CORBA.Util;import java.util.List;///这是主界面 861public class MHLView { private boolean loop = true;//控制是否退出菜单 private String key = "";///接收用户输入 //定义Employervice属性 862 private EmployeeService employeeService = new EmployeeService(); ///定义DiningTableservice的属性 863 private DiningTableService diningTableService = new DiningTableService(); //定义Menuservice属性 866 private MenuService menuService = new MenuService(); //定义BillService属性 869 private BillService billService = new BillService(); public static void main(String[] args) { new MHLView().mainMenu(); } //完成结账 872 public void payBill(){ System.out.println(========================================)); System.out.print(请选择要结账的餐桌号(-1退出)："); int diningTableId = Utility.readInt(); if(diningTableId==-1){ System.out.println(==============================================); return; } ////验证餐桌是否存在 DiningTable diningTable = diningTableService.getDiningTableById(diningTableId); if(diningTable==null){ System.out.println(============================); return; } ////验证餐桌是否有结账单 if(!billService.hasPayBillByDiningTableId(diningTableId)){ System.out.println(========================================); return; } System.out.print((结账方式(现金/支付宝/微信)-返回车辆表示退出); String payMode = Utility.readString(20, "");//如果回车，回归"""""" if("".equals(payMode)){ System.out.println(===============================)); return; } char key = Utility.readConfirmSelection(); if(key=='Y'){ //结账 if(billService.payBill(diningTableId,payMode)){ System.out.println(=============================================); }else{ System.out.println(===============================================); } }else{ System.out.println(===============================)); } } //显示账单信息 870 public void listBill(){// List bills = billService.list();// System.out.println("\n号码\n号码\n号码t/\t菜品号码\/\tt\t菜品量\\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(===============================================); //显示所有账单并带有菜名，价格 873-874 List multiTableBeans = billService.list2(); System.out.println("\n号码\n号码\n号码t/\t菜品号码\/\tt\t菜品量\\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菜名\t\t价格”; for (MultiTableBean bill : multiTableBeans) { System.out.println(bill); } System.out.println(===============================================); } //完成点餐 869 public void orderMenu(){ System.out.println(===========================)); System.out.println(请输入点餐桌号(-1退出); int orderDiningTableId = Utility.readInt(); if(orderDiningTableId==-1){ System.out.println(============================n"); return; } System.out.println(请输入菜品号(-1退出); int orderMenuId = Utility.readInt(); if(orderMenuId==-1){ System.out.println(============================n"); return; } System.out.println(请输入点菜量(-1退出); int orderNums = Utility.readInt(); if(orderNums==-1){ System.out.println(============================n"); return; } ///开始验证餐桌号是否存在 DiningTable diningTable= diningTableService.getDiningTableById(orderDiningTableId); if (diningTable==null){ System.out.println(===============; return; } ///验证菜号 Menu menu = menuService.getMenuById(orderMenuId); if(menu == null){ System.out.println(==============================================); return; } //点餐 if(billService.orderMenu(orderMenuId,orderNums,orderDiningTableId)){ System.out.println(===========================)); }else{ System.out.println(=============================); } } //显示所有菜品 866 public void listMenu(){ List list = menuService.list(); System.out.println(”\t\t菜名\t\t类别\t\t价格”; for (Menu menu : list) { System.out.println(menu); } System.out.println(==========================================)); } //完成订座 865 public void orderDiningTable(){ System.out.println(=============================)); System.out.print(请选择预定的餐桌编号(-1退出); int orderId = Utility.readInt(); if(orderId==-1){ System.out.println(========================); return; } ///这种方法是Y或N char key = Utility.readConfirmSelection(); if(key=='Y(){//要预订 ///根据orderId返回相应的Diningtable对象，如果是null，说明对象不存在 DiningTable diningTable = diningTableService.getDiningTableById(orderId); if(diningTable==null)判断餐桌是否存在{/// System.out.println(==============================); return; } ///判断餐桌是否“空” if(!("空".equals(diningTable.getState())){//为空预订，反之亦然，不是空的，也不是不可预测的 System.out.println(=======================”; return; } //这是可以真正预订的，更新餐桌状态 System.out.print("预定人的名字:"); String orderName = Utility.readString(50); System.out.print("预定人的电话号码:"); String orderTel = Utility.readString(50); ///更新餐桌状态 if(diningTableService.orderDiningTable(orderId,orderName,orderTel)){ System.out.println(=====================================); }else{ System.out.println(======================================); } }else{ System.out.println(========================); } } ///显示所有餐桌状态 863 public void listDiningTable(){ List list = diningTableService.list(); System.out.println("\n餐桌号码\nt\t餐桌状态; ///遍历返回的集合，增强for for (DiningTable diningTable : list) { System.out.println(diningTable); } System.out.println(==================)); } //显示主菜单 861 private void mainMenu(){ while(loop){ System.out.println(=================================)); 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("请输入您的选择:"); 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); ///去数据库判断 862 Employee employee = employeeService.getEmployeeByIdAndPwd(empId, pwd); if(employee!=null){///不得空说明用户存在 System.out.println(===========成功登录[”+employee.getName()===============n"); //显示二级菜单， 这里的二级菜单是循环操作，所以做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 预订餐桌”); System.out.println("\t\t 3 展示所有菜品”); 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(“请输入您的选择： "); key = Utility.readString(1); switch (key) { case "1": // 863 listDiningTable(); break; case "2": //864-865 orderDiningTable(); break; case "3": //866 listMenu(); break; case "4": //869 orderMenu(); break; case "5": //870 listBill(); break; case "6": //871-872 payBill(); break; case "9": loop = false; break; default: System.out.println(”你的输入是错误的，请重新输入”); break; } } }else{ System.out.println(=====================); } break; case "2": System.out.println(“退出满汉楼”; loop = false; break; default: System.out.println(”你的输入是错误的，请重新输入："); } } System.out.println(你退出了满汉楼系统~); }}package com.stulzl.mhl.service;import com.stulzl.mhl.dao.EmployeeDAO;import com.stulzl.mhl.domain.Employee;///完成Employee表的各种操作(通过调用Employeedao对象完成) 862public class EmployeeService {///业务层 //定义EmployeedAO属性 private EmployeeDAO employeeDAO = new EmployeeDAO(); //方法，根据empId 和 pwd 回到Employeee对象 //如果找不到，返回空nullll public Employee getEmployeeByIdAndPwd(String empId,String pwd){ return employeeDAO.querySingle("select * from employee where empId=? and pwd=md5(? and pwd=md5() , Employee.class, empId, pwd); }}package com.stulzl.mhl.service;import com.stulzl.mhl.dao.DiningTableDAO;import com.stulzl.mhl.domain.DiningTable;import java.util.List;///完成Diningtable表的各种操作(通过调用Diningtabledao对象完成) 863public class DiningTableService {///业务层 //定义DiningTableDAO对象 private DiningTableDAO diningTableDAO = new DiningTableDAO(); ////返回所有餐桌信息 863 public List list(){ return diningTableDAO.queryMulti("select id, state from diningTable" , DiningTable.class); } 如果返回空nulll，//根据id查询相应的餐桌Diningtable对象，这意味着id对应的桌子不存在 864 public DiningTable getDiningTableById(int id){ return diningTableDAO.querySingle("select * from diningTable where id=?" ,DiningTable.class,id); } //如果餐桌可以预订，调用方法更新其状态（包括预订人的姓名和电话号码） 864 public boolean orderDiningTable(int id,String orderName,String orderTel){ ////这里结束update的返回值代表受影响的行数 int update = diningTableDAO.update("update diningTable set state=已经预定了，orderName=?,orderTel=?,orderTel=? where id=?", orderName, orderTel,id); return update>0;//update>0代表更新成功，否则不成功 } ///需要提供更新餐桌状态的方法 868 public boolean updateDiningTableState(int id,String state){ int update = diningTableDAO.update("update diningTable set state=? where id=?" , state, id); return update>0;//update>0说明更新成功，返回true，否则返回false } //提供方法，将指定的餐桌修改为空闲 871 public boolean updateDiningTableToFree(int id,String state){ int update = diningTableDAO.update("update diningTable set state=?,orderName='',orderTel='' where id=?,orderName='',orderTel='' where id=?" , state, id); return update>0;//update>0说明更新成功，返回true，否则返回false }}package com.stulzl.mhl.service;import com.stulzl.mhl.dao.MenuDAO;import com.stulzl.mhl.domain.Menu;import java.util.List;///完成Menu表的各种操作(通过调用MenuDAO对象完成) 866public class MenuService { ///定义MenuDAO属性 private MenuDAO menuDAO = new MenuDAO(); ///返回所有菜肴，给界面使用 public List list(){ return menuDAO.queryMulti("select * from menu", Menu.class); } ///需要一种方法根据id返回menu对象 868 public Menu getMenuById(int id){ return menuDAO.querySingle("select * from menu where id = ?",Menu.class,id); }}package com.stulzl.mhl.service;import com.stulzl.mhl.dao.BillDAO;import com.stulzl.mhl.dao.MultiTableDAO;import com.stulzl.mhl.domain.Bill;import com.stulzl.mhl.domain.MultiTableBean;import java.util.List;import java.util.UUID;///处理与账单相关的业务逻辑 868public class BillService { //定义BillDAO属性 private BillDAO billDAO = new BillDAO(); //定义Menuservice属性 868 private MenuService menuService = new MenuService(); //定义Diningtableservice属性 868 private DiningTableService diningTableService = new DiningTableService(); //定义MultitableDAO对象 873 private MultiTableDAO multiTableDAO = new MultiTableDAO(); ///编写点餐方法 868 //1. 生成账单 //2. 需要更新相应餐桌的状态 //如果成功返回true，否则，返回false public boolean orderMenu(int menuId,int nums,int diningTable){ ///生成帐单号，使用UUID方法 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 values(null,?,?,?,?,?,?,now()"未结账" , billID, menuId, nums , menuService.getMenuById(menuId).getPrice() * nums, diningTable); if(update<=(0)(///生成账单失败) return false; } ///需要更新相应的餐桌状态 return diningTableService.updateDiningTableState(diningTable,“就餐中”); } ///返回所有账单并提供给View 870 public List list(){ return billDAO.queryMulti("select * from bill",Bill.class); } ///返回所有账单，并带有菜名和价格 为View提供 873-874 public List list2(){ return multiTableDAO.queryMulti("SELECT bill.*,NAME,price " + "FROM bill,menu " + "WHERE bill.menuId=menu.Id",MultiTableBean.class); } ///检查餐桌上是否有未结账的账单 871 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;//如果不等于空，说明有未结账的放回true，否则返回false } //完成结账，如果餐桌存在，餐桌上有未结账的账单 871 public boolean payBill(int diningTableId,String payMode){ ///修改bill表 int update = billDAO.update("update bill set state=? where diningTableId=? and state=“未结账” , payMode, diningTableId); if(update<{///修改billll更新失败 return false; } ///修改diningtable表 871 //注意不要直接在这里操作，相反，Diningtableservice应该调用 方法 if(!diningTableService.updateDiningTableToFree(diningTableId,"空")){ return false;//取反代表失败 } return true;///成功修改 }}package com.stulzl.mhl.dao;import com.stulzl.mhl.utils.JDBCUtils_Druid;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 854public class BasicDAO {///指定具体类型的泛型 private QueryRunner qr = new QueryRunner(); //开发通用dml方法，针对任何表 public int update(String sql,Object... parameters){//Object... parameters可变形参 Connection connection = null; try { connection = JDBCUtils_Druid.getConnection(); int update = qr.update(connection, sql, parameters); return update;//回收影响行数 } catch (SQLException e) { throw new RuntimeException(e); } finally { ///关闭连接 JDBCUtils_Druid.close(null,null,connection); } } ///返回多个对象(即查询结果是多行)，所以对于任何表格 /** * * @param sql sql 句子，可以有 ? * @param clazz 传入一个类 Class 对象 比如 Actor.class * @param parameters 传入 ? 具体值可以是多个值 * @return 根据 Actor.class 返回对应的 ArrayList 集合 */ public List queryMulti(String sql, Class clazz, Object...parameters){ Connection connection = null; try { connection = JDBCUtils_Druid.getConnection(); return qr.query(connection, sql, new BeanListHandler(clazz), parameters); } catch (SQLException e) { throw new RuntimeException(e); } finally { ///关闭连接 JDBCUtils_Druid.close(null,null,connection); } } ////查询单行结果的一般方法 public T querySingle(String sql, Class clazz, Object... parameters) { Connection connection = null; try { connection = JDBCUtils_Druid.getConnection(); return qr.query(connection, sql, new BeanHandler(clazz), parameters); } catch (SQLException e) { throw new RuntimeException(e); //编译异常->运行异常 ,抛出 } finally { JDBCUtils_Druid.close(null, null, connection); } } ///单行单列查询方法，即返回单值的方法 public Object queryScalar(String sql, Object... parameters){ Connection connection = null; try { connection = JDBCUtils_Druid.getConnection(); return qr.query(connection, sql, new ScalarHandler(), parameters); } catch (SQLException e) { throw new RuntimeException(e); //编译异常->运行异常 ,抛出 } finally { JDBCUtils_Druid.close(null, null, connection); } }}package com.stulzl.mhl.dao;import com.stulzl.mhl.domain.Employee;// 862//这里是Employeedao继承Basicdao(Basicdao具有基本功能，如果需要其他功能，可以在Employeedao中添加)public class EmployeeDAO extends BasicDAO{ ///也可以在这里写独特的操作}package com.stulzl.mhl.dao;import com.stulzl.mhl.domain.DiningTable;//863//这里是DiningTableDAO继承BasicDAO(BasicDAO具有基本功能，如果需要其他功能，可以添加到DiningTabledao中)public class DiningTableDAO extends BasicDAO { ///也可以在这里写独特的操作}package com.stulzl.mhl.dao;import com.stulzl.mhl.domain.Menu;//866//这里是Menudao继承Basicdao(Basicdao具有基本功能，可在Menudao中添加其他功能）public class MenuDAO extends BasicDAO{ ///也可以在这里写独特的操作}package com.stulzl.mhl.dao;import com.stulzl.mhl.domain.Bill;//868//这里是Bildao继承Basicdao的类别(Basicdao具有基本功能，BillDAO可以添加其他功能）public class BillDAO extends BasicDAO{ ///也可以在这里写独特的操作}package com.stulzl.mhl.dao;import com.stulzl.mhl.domain.MultiTableBean;//873//这里是Multitabledao继承Basicdao(Basicdao具有基本功能，可在Multitabledao中添加其他功能）public class MultiTableDAO extends BasicDAO{}package com.stulzl.mhl.domain;///这是javabean 与employee相对应 862public class Employee { private Integer id; private String empId; private String pwd; private String name; private String job; public Employee() {//无参构造器，底层需要apache-dbutils反射 } 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; }}package com.stulzl.mhl.domain;///这是javabean 与diningtable相对应 863public 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; }}package com.stulzl.mhl.domain;///这一类是javabean 对应menu表 866public 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" + name + "\t\t" + type + "\t\t" + price; }}package com.stulzl.mhl.domain;import java.util.Date;///这是javabean 对应bill表 868public 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; }}package com.stulzl.mhl.domain;import java.util.Date;//这个javabean可以与多张表相映射，用于多表查询 873public 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; ///添加menu表的name字段 873 private String name; ///添加menu表中的price 874 private Double price; public MultiTableBean() { } 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方法 874 public Double getPrice() { return price; } public void setPrice(Double price) { this.price = price; } ///给name setter和getter方法 873 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; }}package com.stulzl.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;///这是基于druid的数据库连接池的工具类 845//将 JDBCUtils 工具类改成 Druid(德鲁伊)实现public class JDBCUtils_Druid { private static DataSource ds; ////在静态代码块中完成ds的初始化 static{ Properties properties = new Properties(); try { properties.load(new FileInputStream("src\\druid.properties")); ds = DruidDataSourceFactory.createDataSource(properties); } catch (Exception e) { e.printStackTrace(); } } ///编写getconection方法 public static Connection getConnection() throws SQLException { return ds.getConnection(); } //关闭连接， 再次强调： 在数据库连接池技术中，close 并非真的断开了连接 //使用它 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) { statement.close(); } if (connection != null) { connection.close(); } } catch (SQLException e) { throw new RuntimeException(e); } }}package com.stulzl.mhl.utils;/**工具类功能：处理各种情况的用户输入，并能根据程序员的需要获得用户控制台输入。*/import java.util.*;/***/public class Utility {///静态属性。。。 private static Scanner scanner = new Scanner(System.in); /** * 功能：读取键盘输入的菜单选项，值：1-5范围 * @return 1——5 */public static char readMenuSelection() { char c; for (; ; ) { String str = readKeyBoard(1, false);////字符串包含一个字符 c = str.charAt(0);///将字符串转换为字符char类型 if (c != '1' && c != '1' && c != '2' && c != '3' && c != '4' && c != '5') { System.out.print(”选错，请重新输入："); } else break; } return c; }/** * 功能：读取键盘输入的字符 * @return 一个字符 */ public static char readChar() { String str = readKeyBoard(1, false);//是一个字符 return str.charAt(0); } /** * 功能：读取键盘输入的字符，如果直接按回车，返回指定的默认值；否则，返回输入的字符 * @param defaultValue 指定的默认值 * @return 默认值或输入字符 */ public static char readChar(char defaultValue) { String str = readKeyBoard(1, true);//要么是空字符串，要么是字符串 return (str.length() == 0) ? defaultValue : str.charAt(0); } /** * 功能：读取键盘输入的整形，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 如果整数或默认值直接返回汽车，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：读取键盘输入字符串指定长度 * @param limit 限制的长度 * @return 字符串指定长度 */ public static String readString(int limit) { return readKeyBoard(limit, false); } /** * 功能：读取键盘输入指定长度的字符串或默认值，如直接返回车辆，则返回默认值，否则，返回字符串 * @param limit 限制的长度 * @param defaultValue 指定的默认值 * @return 字符串指定长度 */ 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 * 小功能，包装在一种方法中. * @return Y或N */ public static char readConfirmSelection() { System.out.println(”确认是否预定(Y/N): "); char c; for (; ; ) {///无限循环 //在这里，将接收到的字符转换为大写字母 //y => Y n=>N String str = readKeyBoard(1, false).toUpperCase(); c = str.charAt(0); if (c == 'Y' || c == 'N') { break; } else { System.out.print(”选错，请重新输入："); } } return c; } /** * 功能： 读一个字符串 * @param limit 读取的长度 * @param blankReturn 假如是true ,表示 可读空字符串。 * 假如false表示 不能读空字符串。 * 假如false表示 不能读空字符串。 * *若输入为空，或输入大于limit的长度，则提示重新输入。 * @return */ private static String readKeyBoard(int limit, boolean blankReturn) { ///定义字符串String line = "";//scanner.hasNextLine() 判断是否有下一行 while (scanner.hasNextLine()) { line = scanner.nextLine();///阅读这一行 //如果line.length=0, 也就是说，用户直接返回if，而不输入任何内容 (line.length() == 0) { if (blankReturn) return line;/如果blankreturn=true,可返回空串 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 limit，提示重写输入 //如果用户的内容如此 >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; }}-- CREATEEEE创建满汉楼数据库 DATABASE mhl-- 创建表employee表(主键id，empId，name，pwd，job等） CREATEEE用户表862# TABLE employee (id INT PRIMARY KEY AUTO_INCREMENT, #empid自增 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; -- 添加数据INSERT INTO employee VALUES(NULL, '6668612', MD5(123456) "张三丰"， '经理');INSERT INTO employee VALUES(NULL, '6668622', “小龙女”，MD5(123456) "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');SELECT * FROM employeeSELECT * FROM employee WHERE empId=666 AND pwd=MD5(123456)-- 创建dingtable 表(id，state，orderName，orderTel...) 863#餐桌表CRETEEETE TABLE diningTable (id INT PRIMARY KEY AUTO_INCREMENT, #自增, 表示餐桌号statetete表示餐桌编号 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测试数据 INTO diningTable VALUES(NULL, "，"，"'');INSERT INTO diningTable VALUES(NULL, ""，"，";INSERT INTO diningTable VALUES(NULL, ""，"，";SELECT * FROM diningTableSELECT id, state FROM diningTableSELECT * FROM diningTable WHERE id=1UPDATE diningTable SET state='空',orderName='',orderTel='' WHERE id=1-- 创建menu表（id，name，type，price） CREETEE66#菜谱 TABLE menu (id INT PRIMARY KEY AUTO_INCREMENT, #自增主键，作为菜谱号(唯一)NAME VARCHAR(50) NOT NULL DEFAULT '',#菜名TYPE VARCHAR(50) NOT NULL DEFAULT '', #菜品类型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 menuSELECT * FROM menu WHERE id = 1-- 增加表billlllll账单表(id, billId, menuId, nums, billDate, money, state, diningTableId) 867#账单流水， 考虑可以分开结账， 并考虑CREEATEEEE的销售情况，分别统计未来不同菜肴的销售情况 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的规则生成 UUIDmenuId INT NOT NULL DEFAULT 0、#菜品编号， 也可以使用外键numss SMALLINT NOT NULL DEFAULT 0,#分数money DOUBLE NOT NULL DEFAULT 0, #diningtabledidid金额 INT NOT NULL DEFAULT 0, #餐桌bildateldatet DATETIME NOT NULL ,#state订单日期 VARCHAR(50) NOT NULL DEFAULT '' # 状态 '未结账' , 已经结账了， "现金"，"支付宝"，'坏账')CHARSET=utf8;SELECT * FROM bill-- 检查餐桌上是否有未结账的账单 871SELECT * FROM bill WHERE diningTableId=1 AND state='未结账' LIMIT 0,1-- 写sql语句，您可以返回菜名和账单信息 873SELECT bill.*,NAMEFROM bill,menuWHERE bill.menuId=menu.Id#key=valuedriverClassName=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/mhl?rewriteBatchedStatements=trueusername=rootpassword=lzl#initial connection SizeinitialSize=10#min idle connecton sizeminIdle=5#max active connection sizemaxActive=50#max wait time (5000 mil seconds)maxWait=5000
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