private ICommandHandler commandHandler

这段代码看起来像是一个类或者结构体中的私有成员变量声明。其中 `commandHandler` 变量的类型应该是 `ICommandHandler`。`ICommandHandler` 接口可能是一个处理命令的接口，该类或结构体利用这个接口来处理命令。因为它是私有成员变量，所以它只能在该类或结构体内部使用，而外部代码无法访问它。

相关问题

// 外观模式 class GameFacade { private CommandHandler commandHandler; private List observers; private GameMediator mediator; private PlayerProxy playerProxy; private GameAdapter gameAdapter; public GameFacade() { commandHandler = new IdentityHandler(); commandHandler.setNextHandler(new CommandValidationHandler()); observers = new ArrayList<>(); observers.add(new StaminaObserver()); observers.add(new ExperienceObserver()); mediator = new GameMediator(); Player player = new PlayerImpl(); playerProxy= new PlayerProxy(player); Game game = new GameImpl(); gameAdapter = new GameAdapter(game); } public void handleCommand(Command command) { commandHandler.handleCommand(command); } public void notifyPlayerAction(PlayerAction action) { for (PlayerActionObserver observer : observers) { observer.onPlayerAction(action); } } public void addServer(Server server) { mediator.addServer(server); } public void syncData(Server server) { mediator.syncData(server); } public void login() { playerProxy.login(); } public void logout() { playerProxy.logout(); } public void setLanguage(Language language) { gameAdapter.setLanguage(language); } public void setGraphics(Graphics graphics) { gameAdapter.setGraphics(graphics); } } 使用外观模式补全以上代码，要求创建一个游戏外观类，封装玩家进行游戏的复杂过程，提供简单的接口给玩家使用。外观类可以处理玩家的命令、游戏操作和界面设置等

// 外观模式
class GameFacade {
private CommandHandler commandHandler;
private List<PlayerActionObserver> observers;
private GameMediator mediator;
private PlayerProxy playerProxy;
private GameAdapter gameAdapter;

public GameFacade() {
commandHandler = new IdentityHandler();
commandHandler.setNextHandler(new CommandValidationHandler());

observers = new ArrayList<>();
observers.add(new StaminaObserver());
observers.add(new ExperienceObserver());

mediator = new GameMediator();

Player player = new PlayerImpl();
playerProxy= new PlayerProxy(player);

Game game = new GameImpl();
gameAdapter = new GameAdapter(game);
}

public void handleCommand(Command command) {
commandHandler.handleCommand(command);
}

public void notifyPlayerAction(PlayerAction action) {
for (PlayerActionObserver observer : observers) {
observer.onPlayerAction(action);
}
}

public void addServer(Server server) {
mediator.addServer(server);
}

public void syncData(Server server) {
mediator.syncData(server);
}

public void login() {
playerProxy.login();
}

public void logout() {
playerProxy.logout();
}

public void setLanguage(Language language) {
gameAdapter.setLanguage(language);
}

public void setGraphics(Graphics graphics) {
gameAdapter.setGraphics(graphics);
}

// 新增方法：玩家开始游戏
public void startGame() {
playerProxy.startGame();
}

// 新增方法：玩家结束游戏
public void endGame() {
playerProxy.endGame();
}

// 新增方法：保存游戏进度
public void saveGame() {
mediator.saveGame();
}

// 新增方法：读取游戏进度
public void loadGame() {
mediator.loadGame();
}
}

// 外观模式 class GameFacade { private CommandHandler commandHandler; private List<PlayerActionObserver> observers; private GameMediator mediator; private PlayerProxy playerProxy; private GameAdapter gameAdapter; public GameFacade() { commandHandler = new IdentityHandler(); commandHandler.setNextHandler(new CommandValidationHandler()); observers = new ArrayList<>(); observers.add(new StaminaObserver()); observers.add(new ExperienceObserver()); mediator = new GameMediator(); Player player = new PlayerImpl(); playerProxy= new PlayerProxy(player); Game game = new GameImpl(); gameAdapter = new GameAdapter(game); } public void handleCommand(Command command) { commandHandler.handleCommand(command); } public void notifyPlayerAction(PlayerAction action) { for (PlayerActionObserver observer : observers) { observer.onPlayerAction(action); } } public void addServer(Server server) { mediator.addServer(server); } public void syncData(Server server) { mediator.syncData(server); } public void login() { playerProxy.login(); } public void logout() { playerProxy.logout(); } public void setLanguage(Language language) { gameAdapter.setLanguage(language); } public void setGraphics(Graphics graphics) { gameAdapter.setGraphics(graphics); } // 新增方法：玩家开始游戏 public void startGame() { playerProxy.startGame(); } // 新增方法：玩家结束游戏 public void endGame() { playerProxy.endGame(); } // 新增方法：保存游戏进度 public void saveGame() { mediator.saveGame(); } // 新增方法：读取游戏进度 public void loadGame() { mediator.loadGame(); } }

这是一个外观模式的实现，它提供了一个简单的接口来操作游戏系统，隐藏了系统的复杂性。其中，CommandHandler、PlayerActionObserver、GameMediator、PlayerProxy和GameAdapter都是游戏系统的组件，通过外观模式，将这些组件组合在一起，提供了更高层次的接口。

通过handleCommand方法，可以处理游戏中的命令；通过notifyPlayerAction方法，可以通知所有的观察者玩家的行为；通过addServer和syncData方法，可以添加服务器和同步数据；通过login和logout方法，可以登录和退出游戏；通过setLanguage和setGraphics方法，可以设置游戏的语言和图形。

此外，还新增了玩家开始游戏、玩家结束游戏、保存游戏进度和读取游戏进度等方法，进一步增强了外观模式的功能。