Java设计模式之备忘录模式_动力节点Java学院

class Originator {   private String state = "";   public String getState() {     return state;   }   public void setState(String state) {     this.state = state;   }   public Memento createMemento(){     return new Memento(this.state);   }   public void restoreMemento(Memento memento){     this.setState(memento.getState());   } } class Memento {   private String state = "";   public Memento(String state){     this.state = state;   }   public String getState() {     return state;   }   public void setState(String state) {     this.state = state;   } } class Caretaker {   private Memento memento;   public Memento getMemento(){     return memento;   }   public void setMemento(Memento memento){     this.memento = memento;   } } public class Client {   public static void main(String[] args){     Originator originator = new Originator();     originator.setState("状态1");     System.out.println("初始状态:"+originator.getState());     Caretaker caretaker = new Caretaker();     caretaker.setMemento(originator.createMemento());     originator.setState("状态2");     System.out.println("改变后状态:"+originator.getState());     originator.restoreMemento(caretaker.getMemento());     System.out.println("恢复后状态:"+originator.getState());   } }