Question

我正在尝试使用 Component.Builder 来注入我的模块，但 RestModule - 我的模块之一出了问题。它返回

错误：（41,5）错误：@ Component.Builder缺少setter 必需的模块或组件： [com.injection.module.services.RestModule]

这是 ApplicationComponent ：

@Singleton
@Component(modules = {PresenterEnvironmentModule.class,
    RestModule.class})
public interface PresenterEnvironmentComponent {


@Component.Builder
interface Builder {

    @BindsInstance
    Builder sharedPreferenceService(SharedPrefService sharedPreferences);

    @BindsInstance
    Builder loggingService(LoggingService loggingService);

    @BindsInstance
    Builder applicationService(Application application);

    @BindsInstance
    Builder connectivityService(ConnectivityService connectivityService);

    @BindsInstance
    Builder schedulersService(SchedulersService schedulersService);

    @BindsInstance
    Builder sessionService(SessionService sessionService);



    PresenterEnvironmentComponent build();

}

@NonNull
PresenterEnvironment presenterEnvironment();

void inject(BaseBootstrapActivity<BaseBootstrapPresenter> baseBootstrapActivity);
}

这是RestModule：

 @Module
 public class RestModule {
 private final boolean debuggable;
 private final String baseUrl;
 @NonNull
 private final TokenInterceptor tokenInterceptor;
 @NonNull
 private final BootstrapRestService bootstrapRestService;
 @Nullable
 private Interceptor[] additionalInterceptors;
 @Nullable
 private Function<OkHttpClient.Builder, OkHttpClient.Builder> onOkHttpClient;
@Nullable
private Function<OkHttpClient.Builder, OkHttpClient.Builder> onOkHttpClientForUploading;

public RestModule(@NonNull RestSettings restSettings) {
    this.debuggable = restSettings.isDebuggable();
    this.baseUrl =  restSettings.getBaseUrl();
    this.tokenInterceptor =   restSettings.getTokenInterceptor();
    this.bootstrapRestService = restSettings.getRestService();
    this.onOkHttpClient = restSettings.getOnOkHttpClient();
    this.onOkHttpClientForUploading = restSettings.getOnOkHttpClientForUploading();
    this.additionalInterceptors =     restSettings.getAdditionalInterceptors();
}

@Provides
@Singleton
@NonNull
@Type.Basic
public OkHttpClient provideOkHttpClient(@NonNull TokenInterceptor tokenInterceptor,
                                        @NonNull HttpLoggingInterceptor loggingInterceptor,
                                        @NonNull OkLogInterceptor okLogInterceptor,
                                        @NonNull CachingInterceptor cacheInterceptor) {
    OkHttpClient.Builder builder = new OkHttpClient.Builder();
    builder.addInterceptor(tokenInterceptor);
    if (additionalInterceptors != null && additionalInterceptors.length > 0) {
        for (Interceptor interceptor : additionalInterceptors) {
            builder.addInterceptor(interceptor);
        }
    }
    if (onOkHttpClient != null) {
        builder = apply(onOkHttpClient, builder);
    }
    if (debuggable) {
        // Add HttpLoggingInterceptor
        builder.addInterceptor(loggingInterceptor);
        // add cache interceptor
        builder.addNetworkInterceptor(cacheInterceptor);
        // add okLog interceptor
        builder.addInterceptor(okLogInterceptor);
    }
    return builder.build();
}

@Provides
@Singleton
@NonNull
@Type.ForUploading
public OkHttpClient provideOkHttpClientForUploading(@NonNull TokenInterceptor tokenInterceptor,
                                                    @NonNull HttpLoggingInterceptor loggingInterceptor,
                                                    @NonNull OkLogInterceptor okLogInterceptor,
                                                    @NonNull CachingInterceptor cacheInterceptor) {
    OkHttpClient.Builder builder = new OkHttpClient.Builder();
    builder.addInterceptor(tokenInterceptor);

    if (additionalInterceptors != null && additionalInterceptors.length > 0) {
        for (Interceptor interceptor : additionalInterceptors) {
            builder.addInterceptor(interceptor);
        }
    }

    if (onOkHttpClientForUploading == null) {
        builder.writeTimeout(60, TimeUnit.SECONDS);
        builder.connectTimeout(60, TimeUnit.SECONDS);
        builder.readTimeout(60, TimeUnit.SECONDS);
    } else {
        builder = apply(onOkHttpClientForUploading, builder);
    }
    if (debuggable) {
        // Add HttpLoggingInterceptor
        builder.addInterceptor(loggingInterceptor);
        // add cache interceptor
        builder.addNetworkInterceptor(cacheInterceptor);
        // add okLog interceptor
        builder.addInterceptor(okLogInterceptor);
    }
    return builder.build();
}

@Provides
@Singleton
@NonNull
public OkLogInterceptor provideOkLogInterceptor() {
    return new OkLogInterceptor.Builder().withAllLogData().build();
}

@Provides
@Singleton
@NonNull
public HttpLoggingInterceptor provideHttpLoggingInterceptor() {
    HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
    interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
    return interceptor;
}

@Provides
@Singleton
@NonNull
@Type.Basic
public Retrofit provideRetrofit(@NonNull @Type.Basic OkHttpClient client) {
    return new Retrofit.Builder()
            .baseUrl(baseUrl)
            .client(client)
            .addConverterFactory(LoganSquareConverterFactory.create())
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .build();
}

@Provides
@Singleton
@NonNull
@Type.ForUploading
public Retrofit provideRetrofitForUploading(@NonNull @Type.ForUploading OkHttpClient client) {
    return new Retrofit.Builder()
            .baseUrl(baseUrl)
            .client(client)
            .addConverterFactory(LoganSquareConverterFactory.create())
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .build();
}

@Provides
@Singleton
@NonNull
public CachingInterceptor provideCachingInterceptor(LoggingService loggingService) {
    return new CachingInterceptor(loggingService);
}

@Provides
@Singleton
@NonNull
public TokenInterceptor provideTokenInterceptor() {
    return tokenInterceptor;
}

@Provides
@Singleton
@NonNull
public BootstrapRestService provideBaseRestService(@NonNull @Type.Basic Retrofit retrofit,
                                                   @NonNull @Type.ForUploading Retrofit retrofitForUploading) {
    return bootstrapRestService.setup(retrofit, retrofitForUploading);
}


@NonNull
private <T, R> R apply(@NonNull Function<T, R> f, @NonNull T t) {
    try {
        return Preconditions.checkNotNull(f.apply(t));
    } catch (Throwable ex) {
        throw new IllegalStateException("Applying function for " + t.toString() + " Threw " + ex);
    }
}



 }

Answer 1

@Module
public class RestModule {
  // ...
  public RestModule(@NonNull RestSettings restSettings) {

RestModule是一个可实例化的模块，没有可见的无参数构造函数。 Dagger不知道如何创建它的实例。您需要在@ Component.Builder上提供Builder restModule(RestModule restModule)之类的方法，并在创建过程中像@BindsInstance方法一样调用它。

Dagger无法实例化的每个模块依赖项（例如，模块没有可见的no-args构造函数）必须具有抽象的setter方法。允许使用其他模块依赖项（Dagger可以实例化的依赖项），但不是必需的。（来自@Component.Builder javadoc）

并非所有模块都是可实例化的;一些是接口或抽象类。因为Dagger静态调用静态方法，并在编译时反映@Binds方法，所以很多模块根本不需要实例化。这通常更为理想，因为Dagger可以跳过创建实例。

对于可实例化但具有可见零-arg构造函数的模块，Dagger可以自动调用new，并且可以将这些模块从Builder中移除。（您可以选择包含它们;它们不需要被调用，但如果您继承模块which the docs advise against anyway，则可能很有用。）

对于可实例化但只有带参数的构造函数的模块，Dagger无法创建模块;它不会像使用@Provides方法那样为构造函数提供图中的参数。您需要显式创建一个Builder方法，并使用您自己创建的模块实例调用它。

@ Component.Builder缺少所需模块或组件的setter [Dagger2]

1 个答案: