java作业(2022/12/6)

收获：第"四"题用到了HashSet，来实现"用户已经报名，不能重复报名"的操作

第一题目：

//购书系统_P70
class Book {
    private int book_id;
    private String bookName;
    private int price;
    private int repertory;

    @Override
    public String toString() {
        return "Book{" +
                "book_id=" + book_id +
                ", bookName='" + bookName + '\'' +
                ", price=" + price +
                ", repertory=" + repertory +
                '}';
    }

    public int getBook_id() {
        return book_id;
    }

    public void setBook_id(int book_id) {
        this.book_id = book_id;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getRepertory() {
        return repertory;
    }

    public void setRepertory(int repertory) {
        this.repertory = repertory;
    }

    public Book(int book_id, String bookName, int price, int repertory) {
        this.book_id = book_id;
        this.bookName = bookName;
        this.price = price;
        this.repertory = repertory;
    }


}

class BuyBook {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Book book[] = new Book[3];
        book[0] = new Book(1, "Java", 58, 100);
        book[1] = new Book(2, "HTML", 38, 100);
        book[2] = new Book(3, "Go", 48, 100);

        System.out.println("请输入id来购买书本：");

        for (Book b : book) {
            System.out.println(Arrays.asList(b));
        }

        boolean flag = true;

        while (flag) {
            int id = scanner.nextInt();
            switch (id) {
                case 1:
                    System.out.println("你选择购买的是：" + book[0]);
                    System.out.println("请输入你要购买" + book[0].getBookName() + "的数量：");
                    int number = scanner.nextInt();
                    int repertory = book[0].getRepertory();
                    book[0].setRepertory(repertory - number);
                    if (book[0].getRepertory() < 0) {
                        System.out.println("没货了");
                        flag = false;
                        break;
                    }
                    System.out.println("你需要支付：" + book[0].getPrice() * number + "元");
                    System.out.println("你还需要购买吗？退出'Y'，继续购买'N' ");
                    String choose = scanner.next();
                    if (choose.equals("N")) {
                        System.out.println("继续购买,继续输入id进行购买...");
                        continue;
                    } else if (choose.equals("N")) {
                        System.out.println("谢谢惠顾，退出购买...");
                        flag = false;
                        break;
                    } else {
                        System.out.println("由于你随便输入，系统判定你退出购买，多读书...");
                        flag = false;
                        break;
                    }

                case 2:
                    System.out.println("你选择购买的是：" + book[1]);
                    System.out.println("请输入你要购买" + book[1].getBookName() + "的数量：");
                    int number1 = scanner.nextInt();
                    int repertory1 = book[0].getRepertory();
                    book[1].setRepertory(repertory1 - number1);
                    if (book[1].getRepertory() < 0) {
                        System.out.println("没货了");
                        flag = false;
                        break;
                    }
                    System.out.println("你需要支付：" + book[1].getPrice() * number1 + "元");
                    System.out.println("你还需要购买吗？退出'Y'，继续购买'N' ");
                    String choose1 = scanner.next();
                    if (choose1.equals("N")) {
                        System.out.println("继续购买,继续输入id进行购买...");
                        continue;
                    } else if (choose1.equals("N")) {
                        System.out.println("谢谢惠顾，退出购买...");
                    } else {
                        System.out.println("由于你随便输入，系统判定你退出购买，多读书...");
                    }

                case 3:
                    System.out.println("你选择购买的是：" + book[2]);
                    System.out.println("请输入你要购买" + book[2].getBookName() + "的数量：");
                    int number2 = scanner.nextInt();
                    int repertory2 = book[2].getRepertory();
                    book[2].setRepertory(repertory2 - number2);
                    if (book[2].getRepertory() < 0) {
                        System.out.println("没货了");
                        flag = false;
                        break;
                    }
                    System.out.println("你需要支付：" + book[1].getPrice() * number2 + "元");
                    System.out.println("你还需要购买吗？退出'Y'，继续购买'N' ");
                    String choose2 = scanner.next();
                    if (choose2.equals("N")) {
                        System.out.println("继续购买,继续输入id进行购买...");
                        continue;
                    } else if (choose2.equals("N")) {
                        System.out.println("谢谢惠顾，退出购买...");
                    } else {
                        System.out.println("由于你随便输入，系统判定你退出购买，多读书...");
                    }

                default:
                    System.out.println("对不起，没有这个书本，请到其他店看看...");
                    flag = false;
                    break;
            }
        }

        System.out.println("库存信息：");
        for (Book b : book) {
            System.out.println(Arrays.asList(b));
        }

    }
}

第二道题

//银行存取卡_P73
class Bank {
    private String account;
    private String password;
    private int money = 500;

    @Override
    public String toString() {
        return "Bank{" +
                "account='" + account + '\'' +
                ", password='" + password + '\'' +
                ", money=" + money +
                '}';
    }

    public int getMoney() {
        return money;
    }

    public void setMoney(int money) {
        this.money = money;
    }

    public String getAccount() {
        return account;
    }

    public void setAccount(String account) {
        this.account = account;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

class TestRegister {
    public static void main(String[] args) {
        int testVerificationCode = 0;
        Random random = new Random();

        Scanner scanner = new Scanner(System.in);
        Bank register = new Bank();
        boolean flag = true;
        while (flag) {
            System.out.println("请输入序号");
            System.out.println("1-登陆系统");
            System.out.println("2-注册系统");
            System.out.println("3-查看账号、密码、存款");
            System.out.println("4-退出系统");
            int i = scanner.nextInt();
            switch (i) {
                case 1:
                    System.out.println("登入你的账号");
                    String account = scanner.next();
                    System.out.println("输入你的密码");
                    String password = scanner.next();
                    if (account.equals(register.getAccount()) && password.equals(register.getPassword())) {
                        System.out.println("为了你的账号安全，请再输入一次密码");
                        String password2 = scanner.next();
                        if (password.equals(password2)) {
                            System.out.println("密码验证成功");
                            System.out.println();
                            int number1 = random.nextInt(8) + 1;
                            int number2 = random.nextInt(8) + 1;
                            int number3 = random.nextInt(8) + 1;
                            int number4 = random.nextInt(8) + 1;
                            testVerificationCode = number1 + number2 + number3 + number4;
                            System.out.println();
                            System.out.println("请输入验证码...");
                            System.out.println("验证码 ：请输出" + number1 + " + " + number2 + " + " + number3 + " + " + number4 + "等于多少");
                            int verificationCode = scanner.nextInt();
                            if (verificationCode == testVerificationCode) {
                                System.out.println("登入成功...");

                                System.out.println();

                                System.out.println("存钱输入'C' // 取钱输入'Q' // 退出'随便'输入 ");
                                String choose = scanner.next();
                                if (choose.equals("Q")) {
                                    System.out.println("尊贵的客人，你的取多少钱？");
                                    int money = scanner.nextInt();
                                    int money1 = register.getMoney();
                                    if (register.getMoney() < money) {
                                        System.out.println("对不起，你的卡没有这么多钱...");
                                        continue;
                                    } else {
                                        register.setMoney(money1 - money);
                                        System.out.println("你已经取出：" + money + "元");
                                        continue;
                                    }
                                } else if (choose.equals("C")) {
                                    System.out.println("尊贵的客人，你的存多少钱？");
                                    int money_c = scanner.nextInt();
                                    int money1 = register.getMoney();
                                    register.setMoney(money1 + money_c);
                                    System.out.println("你已经存出：" + money_c + "元");
                                    continue;
                                } else {
                                    System.out.println("由于你随便输入，系统自动判定你退出...");
                                    break;
                                }

                            } else {
                                System.out.println("你的密码输入错误，请重新登录...");
                                continue;
                            }
                        } else {
                            System.out.println("你的密码输入错误，系统判断你非法登入，已退出程序，请重新登录...");
                            break;
                        }
                    } else {
                        System.out.println("登录失败");
                        System.out.println("因为你登录失败，系统判定你为非法登入，请重修启动系统");
                        flag = false;
                        break;
                    }
                case 2:
                    System.out.println("注册你的账号");
                    String setAccount = scanner.next();
                    register.setAccount(setAccount);
                    System.out.println("注册你的密码");
                    String setPassword = scanner.next();
                    register.setPassword(setPassword);
                    System.out.println("------------------------");
                    continue;
                case 3:
                    System.out.println("你的账号： " + register.getAccount());
                    System.out.println("你的密码：" + register.getPassword());
                    System.out.println("你的存款：" + register.getMoney());
                    System.out.println("------------------------");
                    continue;
                case 4:
                    System.out.println("你还需要操作吗？需要输入'Y'，不需要输入'N'");
                    String next4 = scanner.next();
                    if (next4.equals("Y")) {
                        continue;
                    } else if (next4.equals("N")) {
                        flag = false;
                        break;
                    } else {
                        System.out.println("因为你不按规定输入，系统默认你不再继续操作");
                        flag = false;
                        break;
                    }
                default: {
                    System.out.println("电脑卡顿...");
                    flag = false;
                    break;
                }
            }
        }
    }
}

第三道题：

//查看手机配置和功能_P73
class MobilePhoneConfiguration {
    private String phoneMobile;
    private String phoneType;
    private String phoneOperatingSystem;
    private int phonePrice;
    private int phoneInternal;
    private PhoneFunction phoneFunction;

    public MobilePhoneConfiguration(String phoneMobile,
                                    String phoneType, String phoneOperatingSystem,
                                    int phonePrice, int phoneInternal,
                                    PhoneFunction phoneFunction) {
        this.phoneMobile = phoneMobile;
        this.phoneType = phoneType;
        this.phoneOperatingSystem = phoneOperatingSystem;
        this.phonePrice = phonePrice;
        this.phoneInternal = phoneInternal;
        this.phoneFunction = phoneFunction;
    }

    @Override
    public String toString() {
        return "MobilePhoneConfiguration{" +
                "phoneMobile='" + phoneMobile + '\'' +
                ", phoneType='" + phoneType + '\'' +
                ", phoneOperatingSystem='" + phoneOperatingSystem + '\'' +
                ", phonePrice=" + phonePrice +
                ", phoneInternal=" + phoneInternal +
                ", phoneFunction=" + phoneFunction +
                '}';
    }

    public String getPhoneMobile() {
        return phoneMobile;
    }

    public void setPhoneMobile(String phoneMobile) {
        this.phoneMobile = phoneMobile;
    }

    public String getPhoneType() {
        return phoneType;
    }

    public void setPhoneType(String phoneType) {
        this.phoneType = phoneType;
    }

    public String getPhoneOperatingSystem() {
        return phoneOperatingSystem;
    }

    public void setPhoneOperatingSystem(String phoneOperatingSystem) {
        this.phoneOperatingSystem = phoneOperatingSystem;
    }

    public int getPhonePrice() {
        return phonePrice;
    }

    public void setPhonePrice(int phonePrice) {
        this.phonePrice = phonePrice;
    }

    public int getPhoneInternal() {
        return phoneInternal;
    }

    public void setPhoneInternal(int phoneInternal) {
        this.phoneInternal = phoneInternal;
    }

    public PhoneFunction getPhoneFunction() {
        return phoneFunction;
    }

    public void setPhoneFunction(PhoneFunction phoneFunction) {
        this.phoneFunction = phoneFunction;
    }
}

class PhoneFunction {
    private String phoneCall;
    private String phoneGame;
    private String phoneMusic;

    public PhoneFunction(String phoneCall, String phoneGame, String phoneMusic) {
        this.phoneCall = phoneCall;
        this.phoneGame = phoneGame;
        this.phoneMusic = phoneMusic;
    }

    @Override
    public String toString() {
        return "PhoneFunction{" +
                "phoneCall='" + phoneCall + '\'' +
                ", phoneGame='" + phoneGame + '\'' +
                ", phoneMusic='" + phoneMusic + '\'' +
                '}';
    }

    public String getPhoneCall() {
        return phoneCall;
    }

    public void setPhoneCall(String phoneCall) {
        this.phoneCall = phoneCall;
    }

    public String getPhoneGame() {
        return phoneGame;
    }

    public void setPhoneGame(String phoneGame) {
        this.phoneGame = phoneGame;
    }

    public String getPhoneMusic() {
        return phoneMusic;
    }

    public void setPhoneMusic(String phoneMusic) {
        this.phoneMusic = phoneMusic;
    }
}

class TestMobilePhoneConfiguration {

    public static void main(String[] args) {
        MobilePhoneConfiguration mobilePhoneConfiguration[] = new MobilePhoneConfiguration[3];
        mobilePhoneConfiguration[0] = new MobilePhoneConfiguration("XiaoMi",
                "Utral",
                "安卓系统",
                4000,
                128,
                new PhoneFunction("打电话", "打游戏", "听音乐"));

        mobilePhoneConfiguration[1] = new MobilePhoneConfiguration("HuaWei",
                "Utral",
                "鸿蒙系统",
                8000,
                256,
                new PhoneFunction("打电话", "打游戏", "听音乐"));

        mobilePhoneConfiguration[2] = new MobilePhoneConfiguration("Apple",
                "IOS系统",
                "苹果",
                5000,
                256,
                new PhoneFunction("打电话", "打游戏", "听音乐"));

        System.out.println("手机配置：");
        for (MobilePhoneConfiguration m : mobilePhoneConfiguration) {
            System.out.println(Arrays.asList(m));
        }

    }
}

第四道题

//学生投票系统_P80页
class Voter {
    private String name;
    private String answer;
    private String result;
    private static int count;
    private static final int MAX_COUNT = 10;
    private static HashSet<Voter> voters = new HashSet<>();

    public void VoterFor(String name, String answer) {
        if (count == MAX_COUNT) {
            System.out.println("投票已经达到上线，下次请早点...");
            return;
        }
        this.name = name;
        if (voters.contains(this)) {
            System.out.println(name + "同学你已经投过票了，请不要重复投票...");
        } else {
            count++;
            this.name = name;
            this.answer = answer;
            String total = name + answer;
            this.result =total;
            voters.add(this);
            System.out.println("感谢" + name + "同学的投票...");
        }
    }

    //打印投票信息
    public void printResult() {
        System.out.println("参与投票数量：" + count + "个");
        System.out.println("参与投票的结果如下");
        for (Voter voter : voters) {
            System.out.println(voter.result);
            System.out.println("//---------------------------------");
        }
    }
}

class VoterTest {
    public static void main(String[] args) {
        Voter voter1 = new Voter();
        Voter voter2 = new Voter();
        Voter voter3 = new Voter();

        voter1.VoterFor("tom", "不同意");
        voter1.VoterFor("tom", "不同意");
        voter2.VoterFor("LILI", "一般同意");
        voter3.VoterFor("YAYA", "同意");
        
        voter3.printResult();

    }
}

附加：对第"四"题的解析：

1-目的：

把用户名都放到HashSet里面，在投票前，对HashSet进行判段，如果已经存在这个用户了，就提示"已经投过了"

2-对VoterFor方法的剖析

voters.contains(this)方法，是HashSet的方法，他不能传入"String"。但是可以传入"HashSet"定义过的Class的成员变量。

问：什么是["HashSet"定义过的Class的成员变量]

答1："HashSet"定义过的Class（而且这个Class是Voter）

private static HashSet< Voter > voters = new HashSet<>();

答2：那么Voter这个类的"成员变量"就可以放到"HashSet的方法中"

小结：

1-所以：Voter的成员变量，"name"、"answer"、"result" 可以放到"HashSet的方法中"。

2-比如这道题的：voters.contains(this)和voters.add(this);

3-当然是要成员变量的格式当然是："用this关键字"

            this.name = name;
            this.answer = answer;
            String total = name + answer;
            this.result =total;
            voters.add(this);

总结：