Модернизация с помощью Dagger 2 - android

Вот пример того, как это можно сделать. Надеюсь, это поможет.

@Module
class AppModule(val app: Context) {
    @Provides
    @Singleton
    fun provideContext(): Context = app

    @Provides
    @Singleton
    fun provideDatabase(context: Context): Database = Room.databaseBuilder(context, Database::class.java, "my_db").build()

    @Provides
    @Singleton
    fun provideUserDao(database: Database): UserDao = database.userDao()

    @Provides
    @Singleton
    fun providePostDao(database: Database): PostDao = database.postDao()

    @Provides
    @Singleton
    fun provideCommentsDao(database: Database): CommentDao = database.commentDao()

    @Provides
    @Singleton
    fun provideHttpLogging(): HttpLoggingInterceptor = HttpLoggingInterceptor().apply {
        level = HttpLoggingInterceptor.Level.BODY
    }

    @Provides
    @Singleton
    fun provideOkHttpClient(loggingInterceptor: HttpLoggingInterceptor): OkHttpClient =
        OkHttpClient.Builder().addInterceptor(loggingInterceptor).build()

    @Provides
    @Singleton
    fun provideJackson(): JacksonConverterFactory = JacksonConverterFactory.create()

    @Provides
    @Singleton
    fun provideRetrofit(okHttpClient: OkHttpClient, jackson: JacksonConverterFactory): Retrofit = Retrofit.Builder()
            .client(okHttpClient)
            .baseUrl(baseUrl)
            .addConverterFactory(jackson)
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .build()

    @Provides
    @Singleton
    fun provideApiInterface(retrofit: Retrofit): ApiInterface = retrofit.create(
        ApiInterface::class.java
    )
}