软件设计                  石家庄铁道大学信息学院

实验 20：备忘录模式

本次实验属于模仿型实验，通过本次实验学生将掌握以下内容： 

1、理解备忘录模式的动机，掌握该模式的结构；

2、能够利用备忘录模式解决实际问题。

[实验任务一]：多次撤销

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）。

实验要求：

1. 提交源代码；

2. 注意编程规范。

package test20;

public class Caretaker
{
    private Memento[] array = null;
    private int index;
    private Memento memento;
    public Memento getMemento()
    {
        return memento;
    }
    public void setMemento(Memento memento)
    {
        this.memento=memento;
    }
    public Caretaker(){
        array = new Memento[10];
        index = 0;
    }
    public void addMemento(Memento Memento){
        array[index++] = Memento;
    }
    public Memento preMemento(){
        Memento pop = null;
        try {
            pop = array[--index];
        } catch (Exception e) {
            e.printStackTrace();
        }
        return pop;
    }
}

package test20;

public class main {
    public static void main(String args[]) {
        UserInfoDTO user = new UserInfoDTO();
        Caretaker c = new Caretaker();
        user.setAccount("zhangrong");
        user.setPassword("123456");
        user.setTelNo("130000");
        System.out.println("状态一：");
        user.show();
        c.addMemento(user.saveMemento());
        System.out.println("-----------------");

        user.setPassword("000000");
        user.setTelNo("130111");
        System.out.println("状态二：");
        user.show();
        c.addMemento(user.saveMemento());
        System.out.println("-----------------");

        user.setPassword("111111");
        user.setTelNo("130222");
        System.out.println("状态三：");
        user.show();
        System.out.println("-----------------");

        user.restoreMemento(c.preMemento());
        System.out.println("回到状态二：");
        user.show();
        System.out.println("-----------------");

        user.restoreMemento(c.preMemento());
        System.out.println("回到状态一：");
        user.show();
        System.out.println("-----------------");
    }
}

package test20;

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 test20;

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("账号是" + this.account);
        System.out.println("密码是" + this.password);
        System.out.println("电话是" + this.telNo);
    }
}

#include<iostream>
#include<string>
#include<vector>
using namespace std;
//备忘录
class Memento {
private:
    string account;
    string password;
    string telNo;
public:
    Memento(string account, string password, string telNo) {
        this->account = account;
        this->password = password;
        this->telNo = telNo;
    }

    string getAccount() {
        return account;
    }
    void setAccount(string account) {
        this->account = account;
    }
    string getPassword() {
        return password;
    }
    void setPassword(string password) {
        this->password = password;
    }
    string getTelNo() {
        return telNo;
    }
    void setTelNo(string telNo) {
        this->telNo = telNo;
    }
};
//发起者
class UserInfoDTO {
private:
    string account;
    string password;
    string telNo;
public:
    string getAccount() {
        return account;
    }
    void setAccount(string account) {
        this->account = account;
    }
    string getPassword() {
        return password;
    }
    void setPassword(string password) {
        this->password = password;
    }

    string getTelNo() {
        return telNo;
    }
    void setTelNo(string telNo) {
        this->telNo = telNo;
    }

    Memento saveMemento() {
        Memento memento(account, password, telNo);
        return memento;
    }

    void restoreMenmento(Memento memento) {
        this->account = memento.getAccount();
        this->password = memento.getPassword();
        this->telNo = memento.getTelNo();
    }
    void show() {
        cout << "帐号：" + this->account << endl;
        cout << "密码：" + this->password << endl;
        cout << "电话：" + this->telNo << endl;
    }
};
//管理者
class Caretaker {
private:
    vector<Memento>mementos;
public:
    Memento getMemento(int i) {
        return mementos.at(i);
    }
    void setMemento(Memento memento) {
        mementos.push_back(memento);
    }
};
//测试函数
int main() {
    int index = -1;
    UserInfoDTO user;
    Caretaker taker;

    user.setAccount("zhangrong");
    user.setPassword("123456");
    user.setTelNo("13300000000");
    cout << "状态一：" << endl;
    taker.setMemento(user.saveMemento());
    index++;
    user.show();
    cout << "----------------------------------" << endl;

    user.setPassword("000000");
    user.setTelNo("13300001111");
    cout << "状态二：" << endl;
    taker.setMemento(user.saveMemento());
    index++;
    user.show();
    cout << "----------------------------------" << endl;

    user.setPassword("111111");
    user.setTelNo("13300002222");
    cout << "状态三：" << endl;
    user.show();
    cout << "----------------------------------" << endl;

    cout << "回到状态二:" << endl;
    index--;
    user.restoreMenmento(taker.getMemento(1));
    user.show();
    cout << "----------------------------------" << endl;

    cout << "回到状态一:" << endl;
    index --;
    user.restoreMenmento(taker.getMemento(0));
    user.show();
    cout << "----------------------------------" << endl;

}