Clean架构

app/
  ├─ data/           // 数据层
  │   ├─ repository/  // 仓库实现
  │   ├─ remote/      // 远程数据源
  │   └─ local/       // 本地数据源
  ├─ domain/         // 领域层
  │   ├─ model/       // 领域模型
  │   ├─ repository/  // 仓库接口
  │   └─ usecase/     // 用例
  └─ presentation/   // 表现层
      ├─ ui/          // UI组件
      └─ viewmodel/   // ViewModel

// Domain Layer - Entity
data class User(val id: String, val name: String)
 
// Domain Layer - Repository Interface
interface UserRepository {
    suspend fun getUser(id: String): User
}
 
// Domain Layer - Use Case
class GetUserUseCase(private val repository: UserRepository) {
    suspend operator fun invoke(userId: String): User {
        return repository.getUser(userId)
    }
}
 
// Data Layer - Repository Implementation
class UserRepositoryImpl(private val remoteDataSource: RemoteDataSource) : UserRepository {
    override suspend fun getUser(id: String): User {
        return remoteDataSource.getUser(id)
    }
}
 
// Presentation Layer - ViewModel
class UserViewModel(private val getUserUseCase: GetUserUseCase) : ViewModel() {
    private val _user = MutableLiveData<User>()
    val user: LiveData<User> = _user
 
    fun loadUser(id: String) {
        viewModelScope.launch {
            _user.value = getUserUseCase(id)
        }
    }
}