添加备忘录模式代码

Author: jacksplwxy

src/Memento（备忘录）/README.txt

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src/Memento（备忘录）/common.java

@@ -0,0 +1,60 @@
+
+//备忘录
+class Memento {
+    private state: string;
+    public constructor(state: string) {
+        this.state = state;
+    }
+    public setState(state: string): void {
+        this.state = state;
+    }
+    public getState(): string {
+        return this.state;
+    }
+}
+//发起人
+class Originator {
+    private state: string;
+    public setState(state: string): void {
+        this.state = state;
+    }
+    public getState(): string {
+        return this.state;
+    }
+    public createMemento(): Memento {
+        return new Memento(this.state);
+    }
+    public restoreMemento(m: Memento): void {
+        this.setState(m.getState());
+    }
+}
+//管理者
+class Caretaker {
+    private memento: Memento;
+    public setMemento(m: Memento): void {
+        this.memento = m;
+    }
+    public getMemento(): Memento {
+        return this.memento;
+    }
+}
+
+
+class Client {
+    public static main(): void {
+        const or: Originator = new Originator();
+        const cr: Caretaker = new Caretaker();
+        or.setState("S0");
+        console.log("初始状态:" + or.getState());
+        cr.setMemento(or.createMemento()); //保存状态      
+        or.setState("S1");
+        console.log("新的状态:" + or.getState());
+        or.restoreMemento(cr.getMemento()); //恢复状态
+        console.log("恢复状态:" + or.getState());
+    }
+}
+Client.main()
+
+// 初始状态:S0
+// 新的状态:S1
+// 恢复状态:S0

src/Memento（备忘录）/common.js

@@ -0,0 +1,82 @@
+// 备忘录类
+class Memento {
+    private x: number;
+    private y: number;
+    constructor(x: number, y: number) {
+        this.x = x;
+        this.y = y;
+    }
+    getX(): number {
+        return this.x;
+    }
+    getY(): number {
+        return this.y;
+    }
+}
+
+// 原发器类
+class Role {
+    private x: number;
+    private y: number;
+    constructor(name: string, x: number, y: number) {
+        this.x = x;
+        this.y = y;
+    }
+    // 移动到新的位置
+    moveTo(x: number, y: number): Memento {
+        this.x = x;
+        this.y = y;
+        return this.save();
+    }
+    save(): Memento {
+        return new Memento(this.x, this.y);
+    }
+    // 根据备忘录回退到某一个位置
+    goBack(memento: Memento) {
+        this.x = memento.getX();
+        this.y = memento.getY();
+    }
+}
+
+// 负责人，管理所有备忘录
+class HistoryRecords {
+    private records = [];
+    // 添加备忘录
+    add(record: Memento): void {
+        this.records.push(record);
+    }
+    // 返回备忘录
+    get(index: number): Memento {
+        if (this.records[index]) {
+            return this.records[index];
+        }
+        return null;
+    }
+    // 清除指定位置后面的备忘录
+    cleanRecordsAfter(index: number): void {
+        this.records.slice(0, index + 1);
+    }
+}
+
+
+class Client {
+    public static main(): void {
+        const role = new Role('卡通小人', 0, 0);
+        const records = new HistoryRecords();
+        // 记录初始位置
+        records.add(role.save());
+        // 移动时添加备忘录
+        role.moveTo(10, 10);
+        records.add(role.save());
+        role.moveTo(20, 30);
+        records.add(role.save());
+        // 回退到初始位置
+        const GO_BACK_STEP = 0;
+        const firstMemento = records.get(GO_BACK_STEP);
+        role.goBack(firstMemento);
+        // 清除后面的记录
+        records.cleanRecordsAfter(GO_BACK_STEP);
+    }
+}
+Client.main()
+