Dagger 2依赖注入不起作用

Question

I'm very new to Dagger 2 and I'm trying to get this basic example working with some minor modifications.

This is what I have so far:

Component class

@Component(modules = {MyModule.class})
public interface MyComponent {
void inject(Object object);
} 

Module class

@Module
public class MyModule {

@Provides
@Singleton
public Retrofit getRetrofit(){
  return new Retrofit();
}
}

Static Injector

public class MyStaticInjector {

private static MyComponent di;

public static void inject(Object object){
    if(di == null){
        di = DaggerMyComponent.builder().build();
    }
    di.inject(object);
}
}

The problem is that whenever I do

MyStaticInjector.inject(this);

the annotated fields are still null. I suspect the problem is with the type Object in the interface method. In the example, there's an Activity instead. But I need to use DI in classes that are not activities.

Can anyone help me? Thank you.

Answer 1

Object has no @Inject annotated fields. Thus the injection works just fine—it just has nothing to inject.
You will have to use your actual classes with inject(MyClass) instead of Object , so that the code can be generated and fields can be injected.

Dagger generates source code at compile time . If it does not know about the actual class, it cannot create code for it.