Java设计模式之备忘录模式详解

/**
 * @create: 2021/10/16
 * @author: Tony Stark
 */
public class Memento {
    private  String  state;
    public Memento(String state) {
        this.state=state;
    }
    public String getState() {
        return state;
    }
}

/**
 * @create: 2021/10/16
 * @author: Tony Stark
 */
public class Originator {
    private String state;
    public Memento saveState(){
        return new Memento(state);
    }
    public void getStateMemento(Memento memento){
         state=memento.getState();
    }
    public String getState() {
        return state;
    }
    public void setState(String state) {
        this.state = state;
    }
}

/**
 * @create: 2021/10/16
 * @author: Tony Stark
 */
public class Caretaker {
    private List<Memento> mementoList=new ArrayList<>();
    public  void add(Memento memento){
         mementoList.add(memento);
    }
    public  Memento getIndex(int index){
     return  mementoList.get(index);
    }
}

/**
 * @create: 2021/10/16
 * @author: Tony Stark
 */
public class Client {
    public static void main(String[] args) {
        Originator originator = new Originator();
        Caretaker caretaker = new Caretaker();
        originator.setState("血量100%");
        System.out.println(originator.getState());
        System.out.println("保存当前血量");
        caretaker.add(originator.saveState());
        System.out.println("团战中------->团战结束");
        originator.setState("血量50%");
        System.out.println("剩余血量为------->"+originator.getState());
        originator.getStateMemento(caretaker.getIndex(0));
        System.out.println("回基地补充血量---->血量恢复为---"+originator.getState());
    }
}