超市管理系統

//商品類
public class Goods {
    private String code;
    private String name;
    private double price;
    public Goods() {
    }
    public Goods(String code, String name, double price) {
        this.code = code;
        this.name = name;
        this.price = price;
    }
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
}
//--------------購物車類

public class ShoppingCart extends Goods{

    int count;//數量
    double totalprice; //小計

    public ShoppingCart() {
    }

    public ShoppingCart(String code, String name, double price, int count, double totalprice) {
        super(code, name, price);
        this.count = count;
        this.totalprice = totalprice;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public double getTotalprice() {
        return totalprice;
    }

    public void setTotalprice(int totalprice) {
        this.totalprice = totalprice;
    }

}
----------------購物項類

public class Item {
    private Goods goods ;//商品
    private int amount;
    private  double subtotal;//當前購物項小計

    public Goods getGoods() {
        return goods;
    }

    public void setGoods(Goods goods) {
        this.goods = goods;
    }

    public int getAmount() {
        return amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }

    public double getSubtotal() {
        return subtotal;
    }

    public void setSubtotal(double subtotal) {
        this.subtotal = subtotal;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Item item = (Item) o;
        return amount == item.amount && Double.compare(item.subtotal, subtotal) == 0 && goods.equals(item.goods);
    }

    @Override
    public int hashCode() {
        return Objects.hash(goods, amount, subtotal);
    }
}

-------------------------測試類

public class Supermarket {
    static ArrayList<Goods> goods = new ArrayList<>();
    static ArrayList<User> users = new ArrayList<>();
    static ArrayList<ShoppingCart> car = new ArrayList<>();
    static boolean loginstatus = false;

    public static void main(String[] args) {
        goods.add(new Goods("9001", "核桃1", 11));
        goods.add(new Goods("9002", "核桃2", 22));
        goods.add(new Goods("9003", "核桃3", 33));
        System.out.println("=======================歡迎光臨=======================");
        System.out.println("1：貨物清單 2：添加商品 3：刪除商品 4：修改商品 5：用戶注冊  6.顯示用戶 7.用戶登錄  8.添加購物車 10.顯示購物車 9:退出系統");
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("請輸入您要操作的功能序號");
            int num = sc.nextInt();
           /* if(loginstatus==false){
                login();
            }*/
            if (!loginstatus && (num == 1 || num == 2 || num == 3 || num == 4 || num == 6 || num == 9 || num == 8 || num == 10)) {
                System.out.println("進行此操作需要先登錄");
                login();
            }
            if (loginstatus) {
                if (num == 1) {
                    show();
                } else if (num == 2) {
                    addGoods();
                } else if (num == 3) {
                    delete();
                } else if (num == 4) {
                    update();
                } else if (num == 6) {
                    showUser();
                } else if (num == 9) {
                    exit();
                } else if (num == 8) {
                    addCar();
                } else if (num == 10) {
                    showcar();
                }
            } else {
                if (num == 7) {
                    login();
                } else if (num == 5) {
                    register();
                }
            }


        }

    }

    public static void show() {
        System.out.println("=======================商品庫存清單=======================");
        System.out.println("商品編號            商品名稱            商品單價            ");
        for (int i = 0; i < goods.size(); i++) {
            Goods g = goods.get(i);
            if (g != null) {
                System.out.println(g.getCode() + "            " + g.getName() + "            " + g.getPrice());
            }
        }
    }

    public static void addGoods() {
        System.out.println("=======================添加新貨物=======================");
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入添加的貨品編號");
        String code = sc.next();
        System.out.println("請輸入添加的貨品名稱");
        String name = sc.next();
        System.out.println("請輸入添加的貨品價格");
        Double price = sc.nextDouble();
        Goods g = new Goods(code, name, price);
        goods.add(g);
    }

    public static void delete() {
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入需要刪除的商品編號");
        String code = sc.next();
        //找到要刪除的商品  方法：通過循環
        //循環出來的是一個一個的Goods類型的數據
        //通過循環出來的對象，獲得當前該商品的編號
        //判斷該編號是否和需要刪除的商品編號相同  相等則說明找到了
        for (int i = 0; i < goods.size(); i++) {
            boolean flag = false;
            Goods g = goods.get(i);
            if (g != null && g.getCode().equals(code)) {

                flag = true;

            }
            if (g != null && flag) {
                goods.remove(i);
            }
        }

    }

    public static void update() {
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入要修改的商品編號");
        String code = sc.next();
        boolean flag = true;
        for (int i = 0; i < goods.size(); i++) {
            Goods g = goods.get(i);
            if (g.getCode().equals(code)) {
                System.out.println("請輸入要修改的商品名稱");
                String name = sc.next();
                System.out.println("請輸入要修改的商品單價");
                double price = sc.nextDouble();
                g.setName(name);
                g.setPrice(price);
                flag = true;
                break;
            }
            if (flag) {
                System.out.println("修改成功");
            } else {
                System.out.println("修改失敗");
            }
        }


    }

    public static void exit() {
        System.exit(0);
    }

    public static void register() {
        System.out.println("====================用戶信息注冊===================");
        System.out.println("請輸入用戶名");
        Scanner sc = new Scanner(System.in);
        String uname = sc.next();
        System.out.println("請輸入密碼");
        String password = sc.next();
        User user = new User();
        user.setUname(uname);
        user.setPassword(password);
        users.add(user);
        System.out.println("注冊成功");
    }

    public static void showUser() {
        System.out.println("=======================用戶信息展示=================");
        System.out.println("用戶名            密碼");
        for (int i = 0; i < users.size(); i++) {
            User u = users.get(i);

            System.out.println(u.getUname() + "              " + u.getPassword());
        }
    }


    public static void login() {
        boolean flag = false;
        System.out.println("=======================用戶登錄=================");
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入用戶名");
        String uname = sc.next();
        System.out.println("請輸入密碼");
        String password = sc.next();
        for (int i = 0; i < users.size(); i++) {
            User u = users.get(i);
            if (u != null && u.getPassword().equals(password) && u.getUname().equals(uname)) {
                flag = true;
                break;
            }
        }
        if (flag) {
            System.err.println("登錄成功");
        } else {
            System.err.println("登錄失敗");
        }
        loginstatus = flag;
    }

    public static ShoppingCart shengcheng(String code, int count) {
        ShoppingCart a = null;
        for (int i = 0; i < goods.size(); i++) {
            if (code.equals(goods.get(i).getCode())) {
                Goods g = goods.get(i);
                a = new ShoppingCart(g.getCode(), g.getName(), g.getPrice(), count, 5 * g.getPrice());

            }
        }
        return a;
    }


    public static void addCar() {
        // public ShoppingCart(String code, String name, double price, int count, int totalprice)
        Scanner sc = new Scanner(System.in);
        System.out.println("請輸入您要買的貨品編號");
        String code = sc.next();
        System.out.println("請輸入您要買的貨品數量");
        int count = sc.nextInt();
        for (int i = 0; i < goods.size(); i++) {
            if (code.equals(goods.get(i).getCode())) {
                car.add(shengcheng(code, count));
                System.out.println("添加成功");
                break;
            } else {
                System.out.println("找不到此編號的商品，添加失敗");
                break;
            }

        }
    }

    public static void showcar() {
        for (int i = 0; i < car.size(); i++) {
            System.out.println("編號\t" + "名稱\t" + "單價\t" + "數量\t" + "小計");
            System.out.println(car.get(i).getCode() + "\t" + car.get(i).getName() + "\t" + car.get(i).getPrice() + "\t" + car.get(i).getCount() + "\t" + car.get(i).getTotalprice());
        }
    }
}