1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
| import java.util.ArrayList;
import java.util.List;
class Memento {
String state;
public Memento(String state) {
this.state = state;
}
public String getState() {
return state;
}
}
class Originator {
private String state;
public void setState(String state) {
this.state = state;
}
public String getState() {
return state;
}
public Memento saveStateToMemento() {
return new Memento(state);
}
public void getStateFromMemento(Memento Memento) {
state = Memento.getState();
}
}
class CareTaker {
List<Memento> mementoList = new ArrayList<>();
public void add(Memento state) {
mementoList.add(state);
}
public Memento get(int index) {
return mementoList.get(index);
}
}
public class MementoPatternDemo {
public static void main(String[] args) {
Originator originator = new Originator();
CareTaker careTaker = new CareTaker();
originator.setState("State #1");
originator.setState("State #2");
careTaker.add(originator.saveStateToMemento());
originator.setState("State #3");
careTaker.add(originator.saveStateToMemento());
originator.setState("State #4");
System.out.println("Current State: " + originator.getState());
originator.getStateFromMemento(careTaker.get(0));
System.out.println("First saved State: " + originator.getState());
originator.getStateFromMemento(careTaker.get(1));
System.out.println("Second saved State: " + originator.getState());
}
}
|