Java设计模式初识之备忘录模式详解

public class Memento {
    private String state;
 
    public Memento(Originator o) {
        this.state = o.getState();
    }
 
    public void setState(String State) {
        this.state = state;
    }
 
    public String getState() {
        return this.state;
    }
}

public class Originator {
    private String state;
 
    public Originator() {}
 
    // 创建一个备忘录对象
    public Memento createMemento() {
        return new Memento(this);
    }
 
    // 根据备忘录状态恢复原发器状态
    public void restoreMemento(Memento m) {
        state = m.getState();
    }
 
    public void setState(String State) {
        this.state = state;
    }
 
    public String getState() {
        return this.state;
    }
}

public class Caretaker {
    private Memento memento;
 
    public Memento getMemento() {
        return this.memento;
    }
 
    public void setMemento(Memento memento) {
        this.memento = memento;
    }
}

public class Date implements java.io.Serializable, Cloneable, Comparable<Date> {
    private transient long fastTime;
 
    public Date(long date) {
        fastTime = date;
    }
 
    public long getTime() {
        return getTimeImpl();
    }
 
    private final long getTimeImpl() {
        if (cdate != null && !cdate.isNORMalized()) {
            normalize();
        }
        return fastTime;
    }
}