Java Dagger 2：@Component.Builder 缺少所需模块或组件的设置器：[appi.example.com.dagger.AppModule]`
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Dagger 2: @Component.Builder is missing setters for required modules or components: [appi.example.com.dagger.AppModule]`
提问by Leonardo Deleon
I'm configuring the new Dagger Android module but I got this error Here's my Component:
我正在配置新的 Dagger Android 模块，但出现此错误 这是我的组件：
@AppScope
@Component(modules = {AppModule.class, NetModule.class})
public interface AppComponent {
@Component.Builder
interface Builder {
@BindsInstance
Builder application(ExampleApplication application);
@BindsInstance
Builder appModule(AppModule appModule);
@BindsInstance
Builder netModule(NetModule netModule);
AppComponent build();
}
void inject(ExampleApplication __);
...
Which I build like this in my Application
我在我的应用程序中像这样构建
appComponent = DaggerAppComponent
.builder()
.application(this)
.appModule(new AppModule(this))
.netModule(new NetModule())
.build()
.inject(this);
But I still receive the error
但我仍然收到错误
Error:(20, 3) error: @Component.Builder is missing setters for required modules or components: [app.example.com.dagger.AppModule]
错误：(20, 3) 错误：@Component.Builder 缺少所需模块或组件的设置器：[app.example.com.dagger.AppModule]
According to the documentation that should be right, What am I missing?
根据应该正确的文档，我错过了什么？
For example, this could be a valid Component with a Builder:
例如，这可能是一个带有 Builder 的有效组件：
@Component(modules = {BackendModule.class, FrontendModule.class})
interface MyComponent {
MyWidget myWidget();
@Component.Builder
interface Builder {
MyComponent build();
Builder backendModule(BackendModule bm);
Builder frontendModule(FrontendModule fm);
}
}
采纳答案by Gnanendra Kumar
Remove the below code from the AppModule.class and rebuild the project
从 AppModule.class 中删除以下代码并重建项目
@Provides
@Singleton
Application provideContext(SomeApplication application) {
return application;
}
回答by Hendy Irawan
I think this provides a somewhat clearer explanation on the use of @BindsInstanceand removal of @Provides Application, Dagger 2 Component Builder:
我认为这提供了使用的更为清楚的解释@BindsInstance和去除@Provides Application，匕首2组件生成器：
@BindsInstanceWhat?Here's the definition :
Marks a method on a component builder or subcomponent builder that allows an instance to be bound to some type within the component.?—?source
WHAAT? I don't understand it either
Here's a simple hint of when to use it :
@BindsInstance methods should be preferred to writing a @Module with constructor arguments and immediately providing those values.?—?source
@BindsInstance什么？这是定义：
在组件构建器或子组件构建器上标记一个方法，该方法允许将实例绑定到组件内的某种类型。?—?source
什么？我也不明白
这是何时使用它的简单提示：
@BindsInstance 方法应该优先于编写带有构造函数参数的 @Module 并立即提供这些值。?-?source
I come from Spring Boot and Dagger 2 is OMG so much more complicated. :(
我来自 Spring Boot，而 Dagger 2 是 OMG 复杂得多。:(
So based on my extremely limited experience with Dagger 2, this happens because there a *Modulewith a constructor argument which is improperly configured. I still don't know how to properly configure the Module with a constructor argument, but I rather follow recommended approach given by Dagger 2 documentation, and that is to remove the constructor argument(s) and use @BindsInstanceand @Injectinstead.
因此，根据我对 Dagger 2 极其有限的经验，发生这种情况是因为有*Module一个构造函数参数配置不正确。我仍然不知道如何使用构造函数参数正确配置模块，但我宁愿遵循 Dagger 2 文档给出的推荐方法，即删除构造函数参数并使用@BindsInstanceand@Inject代替。
e.g.
例如
@Module
class NetModule { // no constructor argument here!
@Inject @Named("mqttServer") // replaced by @Inject
internal lateinit var mqttServer: String
}
and in AppComponent:
并在AppComponent：
@Singleton
@Component(modules = [AndroidSupportInjectionModule::class, AppModule::class, NetModule::class, ActivityBuilder::class])
interface AppComponent {
@Component.Builder
interface Builder {
@BindsInstance
fun application(application: Application): Builder
@BindsInstance // you'll call this when setting up Dagger
fun mqttServer(@Named("mqttServer") mqttServer: String): Builder
fun build(): AppComponent
}
fun inject(app: GeoAssistantApp)
}
Then you provide the dependencies of the modules when constructing the DaggerAppComponentfrom the Applicationsubclass (make sure you specify the subclass name in AndroidManifest.xml):
然后在DaggerAppComponent从Application子类构造 时提供模块的依赖项（确保在 中指定子类名称AndroidManifest.xml）：
class GeoAssistantApp : Application(), HasActivityInjector, HasSupportFragmentInjector {
@Inject
internal lateinit var activityDispatchingAndroidInjector: DispatchingAndroidInjector<Activity>
@Inject
internal lateinit var fragmentDispatchingAndroidInjector: DispatchingAndroidInjector<Fragment>
override fun onCreate() {
super.onCreate()
Log.i(GeoAssistantApp::class.java.simpleName, "Initializing DaggerAppComponent...")
DaggerAppComponent.builder()
// list of modules/dependencies of modules that are part of this component need to be created here too
.application(this)
.mqttServer(getString(R.string.mqtt_server))
.build()
.inject(this)
}
override fun activityInjector(): AndroidInjector<Activity> {
return activityDispatchingAndroidInjector
}
override fun supportFragmentInjector(): AndroidInjector<Fragment> {
return fragmentDispatchingAndroidInjector
}
}
Note that the support-v4Fragmentvs native Fragmentusage can be a source of problems. e.g. for support-v4, you need to use AndroidSupportInjectionModule, HasSupportFragmentInjector, while with native, you need to use AndroidInjectionModule, HasFragmentInjector.
请注意，support-v4Fragmentvs 本机Fragment使用可能是问题的根源。例如，对于 support-v4，您需要使用AndroidSupportInjectionModule, HasSupportFragmentInjector，而对于本机，您需要使用AndroidInjectionModule, HasFragmentInjector。
回答by Federico Torres
In my case I was using an object Module, so I had to annotate provider method with @JvmStatic
在我的例子中，我使用的是一个对象模块，所以我不得不用 @JvmStatic 注释提供者方法
@Module
object GsonModule {
@JvmStatic
@Singleton
@Provides
fun provideGson() = Gson()
}
