实现命令模式示例，添加接收者、命令及传令官类，增强代码可读性

2026-01-05 01:28:20 +08:00
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+/*
+实例：
+汤宝宝成为一国之王，手下有一个传令官和三个大臣，分别是内政大臣、外交大臣和军事大臣。
+有一天，汤宝宝想要发布一个命令，传令官负责将命令传达给大臣们，大臣们根据命令的内容决定是否执行。
+*/
+
+// 接收者接口
+interface Receiver {
+  perform(): void;
+  abort(): void;
+}
+
+// 具体接收者：内政大臣
+class HomeSecretary implements Receiver {
+  isPerforming: boolean;
+  constructor() {
+    this.isPerforming = false;
+  }
+
+  perform(): void {
+    this.isPerforming = true;
+    console.log("内政大臣开始执行命令");
+  }
+
+  abort(): void {
+    this.isPerforming = false;
+    console.log("内政大臣取消执行命令");
+  }
+}
+
+// 具体接收者：外交大臣
+class ForeignSecretary implements Receiver {
+  isPerforming: boolean;
+  constructor() {
+    this.isPerforming = false;
+  }
+
+  perform(): void {
+    this.isPerforming = true;
+    console.log("外交大臣开始执行命令");
+  }
+
+  abort(): void {
+    this.isPerforming = false;
+    console.log("外交大臣取消执行命令");
+  }
+}
+
+// 具体接收者：军事大臣
+class MilitarySecretary implements Receiver {
+  isPerforming: boolean;
+  constructor() {
+    this.isPerforming = false;
+  }
+
+  perform(): void {
+    this.isPerforming = true;
+    console.log("军事大臣开始执行命令");
+  }
+
+  abort(): void {
+    this.isPerforming = false;
+    console.log("军事大臣取消执行命令");
+  }
+}
+
+// 命令接口
+interface Command {
+  execute(): void;
+}
+
+// 执行命令
+class PerformCommand implements Command {
+  receiver: Receiver;
+
+  constructor(receiver: Receiver) {
+    this.receiver = receiver;
+  }
+
+  execute(): void {
+    this.receiver.perform();
+  }
+}
+
+// 取消命令
+class AbortCommand implements Command {
+  receiver: Receiver;
+
+  constructor(receiver: Receiver) {
+    this.receiver = receiver;
+  }
+  execute(): void {
+    this.receiver.abort();
+  }
+}
+
+// 传令官
+class Herald {
+  private commands: Command[] = [];
+
+  addCommand(command: Command): void {
+    this.commands.push(command);
+  }
+  executeCommands(): void {
+    for (const command of this.commands) {
+      command.execute();
+    }
+    this.commands = []; // 执行完后清空命令列表
+  }
+}
+
+(function () {
+  console.log("======= 命令模式开始 =======");
+
+  // 创建接收者
+  const homeSecretary = new HomeSecretary();
+  const foreignSecretary = new ForeignSecretary();
+  const defenseSecretary = new MilitarySecretary();
+
+  // 创建命令
+  const performHomeCommand = new PerformCommand(homeSecretary);
+  const abortHomeCommand = new AbortCommand(homeSecretary);
+  const performForeignCommand = new PerformCommand(foreignSecretary);
+  const abortForeignCommand = new AbortCommand(foreignSecretary);
+  const performDefenseCommand = new PerformCommand(defenseSecretary);
+  const abortDefenseCommand = new AbortCommand(defenseSecretary);
+
+  // 创建传令官
+  const herald = new Herald();
+
+  // 添加命令
+  herald.addCommand(performHomeCommand);
+  herald.addCommand(performForeignCommand);
+  herald.addCommand(performDefenseCommand);
+
+  // 执行命令
+  herald.executeCommands();
+
+  // 取消命令
+  herald.addCommand(abortHomeCommand);
+  herald.addCommand(abortForeignCommand);
+  herald.addCommand(abortDefenseCommand);
+
+  // 执行取消命令
+  herald.executeCommands();
+
+  console.log("\n======= 命令模式结束 =======");
+})();