如何将依赖注入实现接口的类？

// 定义接口
public interface MessageService {
    void sendMessage(String message);
}

// 实现接口的类
public class EmailService implements MessageService {
    public void sendMessage(String message) {
        System.out.println("Sending email: " + message);
    }
}

public class SMSService implements MessageService {
    public void sendMessage(String message) {
        System.out.println("Sending SMS: " + message);
    }
}

// 创建依赖注入容器
public class DIContainer {
    private Map<Class<?>, Object> instances;

    public DIContainer() {
        instances = new HashMap<>();
    }

    public void register(Class<?> clazz, Object instance) {
        instances.put(clazz, instance);
    }

    public <T> T resolve(Class<T> clazz) {
        return (T) instances.get(clazz);
    }
}

// 使用依赖注入
public class Main {
    public static void main(String[] args) {
        // 创建依赖注入容器
        DIContainer container = new DIContainer();

        // 注册接口和对应的实现类
        container.register(MessageService.class, new EmailService());

        // 获取依赖对象并使用
        MessageService messageService = container.resolve(MessageService.class);
        messageService.sendMessage("Hello, DI!");

        // 注册另一个实现类
        container.register(MessageService.class, new SMSService());

        // 获取新的依赖对象并使用
        messageService = container.resolve(MessageService.class);
        messageService.sendMessage("Hello, DI with SMS!");
    }
}