二十三种设计模式全面解析-解密中介者模式：构建灵活的通信桥梁

// 中介者接口
interface ChatMediator {
    void sendMessage(String message, User user);
    void addUser(User user);
}
// 具体中介者
class ChatMediatorImpl implements ChatMediator {
    private List<User> users;
    public ChatMediatorImpl() {
        this.users = new ArrayList<>();
    }
    @Override
    public void sendMessage(String message, User user) {
        for (User u : users) {
            if (u != user) {
                u.receiveMessage(message);
            }
        }
    }
    @Override
    public void addUser(User user) {
        users.add(user);
    }
}
// 组件接口
interface User {
    void sendMessage(String message);
    void receiveMessage(String message);
}
// 具体组件
class ChatUser implements User {
    private String name;
    private ChatMediator mediator;
    public ChatUser(String name, ChatMediator mediator) {
        this.name = name;
        this.mediator = mediator;
    }
    @Override
    public void sendMessage(String message) {
        mediator.sendMessage(message, this);
    }
    @Override：
public void receiveMessage(String message) {
        System.out.println(name + " received message: " + message);
    }
}
// 示例代码的使用
public class Main {
    public static void main(String[] args) {
        ChatMediator mediator = new ChatMediatorImpl();
        User user1 = new ChatUser("User1", mediator);
        User user2 = new ChatUser("User2", mediator);
        User user3 = new ChatUser("User3", mediator);
        mediator.addUser(user1);
        mediator.addUser(user2);
        mediator.addUser(user3);
        user1.sendMessage("Hello, everyone!");
        user2.sendMessage("Hi, User1!");
    }
}