设计模式管理状态之memento备忘录模式

十八、memento备忘录 存储状态

public class Memento {
    int money;
    Vector fruits;
    public int getMoney(){
        return money;
    }

    Memento(int money) {
        this.money = money;
        this.fruits=new Vector();
    }
    void addFruit(String fruit){
        fruits.add(fruit);
    }
    Vector getFruits(){
        return (Vector) fruits.clone();
    }
}

public class Gamer {
    private int money;
    private Vector fruits=new Vector();
    private Random random=new Random();
    private String[] fruitsName={
            "苹果","葡萄","香蕉","橘子",
    };
    private String fruit;

    public Gamer(int money){
        this.money=money;
    }
    public int getMoney(){
        return money;
    }

    public void bet() {
        int dice = random.nextInt(6) + 1;
        if (dice == 1) {
            money += 100;
            System.out.println("我们的金钱多了哦");
        } else if (dice == 2) {
            money /= 2;
            System.out.println("哎，金钱少了一半呢");
        } else if (dice == 6) {
            String fruit = getFruit();
            System.out.println("我们又好吃的水果（"+fruit+")");
            fruits.add(fruit);
        }else {
            System.out.println("啥事也没有");
        }
    }
    public Memento createMemento(){
        Memento m = new Memento(money);
        Iterator iterator = fruits.iterator();
        while (iterator.hasNext()){
            String f= (String) iterator.next();
            if (f.startsWith("好吃的")){
                m.addFruit(f);
            }
        }
        return m;
    }
    public void restoreMemento(Memento memento){
        this.money=memento.money;
        this.fruits=memento.getFruits();
    }

    @Override
    public String toString() {
        return "Gamer{" +
                "money=" + money +
                ", fruits=" + fruits +
                '}';
    }

    private String getFruit() {
        String prefix="";
        if (random.nextBoolean()){
            prefix="好吃的";
        }
        return prefix+fruitsName[random.nextInt(fruitsName.length)];
    }
}

public class Test {
    public static void main(String[] args) {
        Gamer gamer = new Gamer(100);
        Memento memento = gamer.createMemento();
        for (int i = 0; i < 100; i++) {
            System.out.println("====="+i);
            System.out.println("现况==="+gamer);
            gamer.bet();
            System.out.println("手边的金钱有"+memento.getMoney());
            if (gamer.getMoney()>memento.getMoney()){
                System.out.println("赢了不少钱，存储巅峰");
                memento=gamer.createMemento();
            }else if (gamer.getMoney()<memento.getMoney()/2){
                System.out.println("输了一般的钱了赶紧恢复状态吧");
                gamer.restoreMemento(memento);
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("");
        }
    }
}