메멘토 패턴

// Memento 클래스 class EditorMemento { private final String content; public EditorMemento(String content) { this.content = content; } public String getContent() { return content; } } // Originator 클래스 class Editor { private String content; public void setContent(String content) { this.content = content; } public EditorMemento save() { return new EditorMemento(content); } public void restore(EditorMemento memento) { content = memento.getContent(); } } // Caretaker 클래스 class History { private List<EditorMemento> states = new ArrayList<>(); public void push(EditorMemento state) { states.add(state); } public EditorMemento pop() { return states.remove(states.size() - 1); } }