备忘录模式

题目：

改进课堂上的“用户信息操作撤销”实例，使得系统可以实现多次撤销（可以使用HashMap、ArrayList等集合数据结构实现）。

java实现

package memento;

public class Memento {
    private String account;
    private String password;
    private String telNo;

    public Memento(String account, String password, String telNo) {
        this.account = account;
        this.password = password;
        this.telNo = telNo;
    }

    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;
    }

    public String getTelNo() {
        return telNo;
    }

    public void setTelNo(String telNo) {
        this.telNo = telNo;
    }
}

package memento;

public class UserInfoDTO {
    private String account;
    private String password;
    private String telNo;

    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;
    }

    public String getTelNo() {
        return telNo;
    }

    public void setTelNo(String telNo) {
        this.telNo = telNo;
    }

    public Memento saveMemento(){
        return new Memento(account,password,telNo);
    }
    public void restoreMemento(Memento memento) {
        this.account=memento.getAccount();
        this.password=memento.getPassword();
        this.telNo=memento.getTelNo();
    }
    public void show() {
        System.out.println("Account:"+this.account);
        System.out.println("Password:"+this.password);
        System.out.println("TelNo:"+this.telNo);
    }
}

package memento;

import java.util.ArrayList;
import java.util.List;

public class Caretaker {
    private List<Memento> list = new ArrayList<>();

    public Memento getMemento(){
        Memento m = list.get(list.size()-1);
        list.remove(list.size()-1);
        return m;
    }

    public void setMemento(Memento m){
        list.add(m);
    }
}

package memento;

public class Client {
    public static void main(String[] args) {
        UserInfoDTO user = new UserInfoDTO();
        Caretaker caretaker = new Caretaker();

        user.setAccount("张三");
        user.setPassword("123456");
        user.setTelNo("11111111111");
        System.out.println("状态一:");
        user.show();
        caretaker.setMemento(user.saveMemento());
        System.out.println("----------------------------------");
        user.setPassword("222222");
        user.setTelNo("11111112222");
        System.out.println("状态二");
        user.show();
        caretaker.setMemento(user.saveMemento());
        System.out.println("----------------------------------");
        user.setPassword("333333");
        user.setTelNo("11111113333");
        System.out.println("状态三");
        user.show();
        caretaker.setMemento(user.saveMemento());
        System.out.println("----------------------------------");
        user.setPassword("444444");
        user.setTelNo("11111114444");
        System.out.println("状态四");
        user.show();
        caretaker.setMemento(user.saveMemento());
        System.out.println("----------------------------------");
        user.setPassword("555555");
        user.setTelNo("11111115555");
        System.out.println("状态五");
        user.show();
        caretaker.setMemento(user.saveMemento());
        System.out.println("----------------------------------");

        user.restoreMemento(caretaker.getMemento());
        System.out.println("回到状态五：");
        user.show();
        System.out.println("----------------------------------");
        user.restoreMemento(caretaker.getMemento());
        System.out.println("回到状态四：");
        user.show();
        System.out.println("----------------------------------");
        user.restoreMemento(caretaker.getMemento());
        System.out.println("回到状态三：");
        user.show();
        System.out.println("----------------------------------");
        user.restoreMemento(caretaker.getMemento());
        System.out.println("回到状态二：");
        user.show();
        System.out.println("----------------------------------");
        user.restoreMemento(caretaker.getMemento());
        System.out.println("回到状态一：");
        user.show();
        System.out.println("----------------------------------");
    }
}

c++

#include<iostream>
#include<list>

using namespace std;

class Memento {
private:
    string account;
    string pwd;
    string tel;
public:
    string getAccount() {
        return account;
    }

    void setAccount(string account) {
        this->account = account;
    }

    string getPwd() {
        return pwd;
    }

    void setPwd(string pwd) {
        this->pwd = pwd;
    }

    string getTel() {
        return tel;
    }

    void setTel(string tel) {
        this->tel = tel;
    }

    Memento(string account, string pwd, string tel) {
        this->account = account;
        this->pwd = pwd;
        this->tel = tel;
    }
};

class UserInfo {
private:
    string account;
    string pwd;
    string tel;
public:
    string getAccount() {
        return account;
    }

    void setAccount(string account) {
        this->account = account;
    }

    string getPwd() {
        return pwd;
    }

    void setPwd(string pwd) {
        this->pwd = pwd;
    }

    string getTel() {
        return tel;
    }

    void setTel(string tel) {
        this->tel = tel;
    }

    Memento *saveMemento() {
        return new Memento(account, pwd, tel);
    }

    void restoreMemento(Memento *memento) {
        this->account = memento->getAccount();
        this->pwd = memento->getPwd();
        this->tel = memento->getTel();
    }

    void show() {
        cout << "account:" << this->account << endl;
        cout << "pwd:" << this->pwd << endl;
        cout << "tel:" << this->tel << endl;
    }
};

class Caretaker {
private:
    list<Memento *> list;
public:
    Memento *getMemento() {
        list.pop_front();
        Memento *m = list.front();
        return m;
    }

    void setMemento(Memento *m) {
        list.push_front(m);
    }
};

int main() {
    UserInfo *user = new UserInfo();
    Caretaker *c = new Caretaker();
    user->setAccount("张三");
    user->setPwd("123456");
    user->setTel("1310000000");
    cout<<"状态一:"<<endl;
    user->show();
    c->setMemento(user->saveMemento());
    cout<<"-----------------------------"<<endl;

    user->setPwd("111111");
    user->setTel("1310001111");
    cout<<"状态二:"<<endl;
    user->show();
    c->setMemento(user->saveMemento());
    cout<<"-----------------------------"<<endl;

    user->setPwd("zyx666");
    user->setTel("15733333333");
    cout<<"状态三:"<<endl;
    user->show();
    c->setMemento(user->saveMemento());
    cout<<"-----------------------------"<<endl;

    user->setPwd("777777");
    user->setTel("15511111111");
    cout<<"状态四:"<<endl;
    user->show();
    c->setMemento(user->saveMemento());
    cout<<"-----------------------------"<<endl;

    user->setPwd("666666");
    user->setTel("17455555555");
    cout<<"状态五:"<<endl;
    user->show();
    c->setMemento(user->saveMemento());
    cout<<"-----------------------------"<<endl;


    user->restoreMemento(c->getMemento());
    cout<<"回到状态四:"<<endl;
    user->show();
    cout<<"-----------------------------"<<endl;

    user->restoreMemento(c->getMemento());
    cout<<"回到状态三:"<<endl;
    user->show();
    cout<<"-----------------------------"<<endl;

    user->restoreMemento(c->getMemento());
    cout<<"回到状态二:"<<endl;
    user->show();
    cout<<"-----------------------------"<<endl;

    user->restoreMemento(c->getMemento());
    cout<<"回到状态一:"<<endl;
    user->show();
    cout<<"-----------------------------"<<endl;
    return 0;
}