Dagger2-组件保持为应用程序中的静态对象

Question

In my Application class, I have my singleton Dagger Component as a static object and reach it via its static getter method.

public class MyApp extends Application {

        private static UtilsComponent utilsComponent;

        @Override
        public void onCreate() {
           ......
        }

        public static UtilsComponent getUtilsComponent(){
            if(utilsComponent == null){
                utilsComponent = DaggerUtilsComponent.builder()
                        .formattersModule(new FormattersModule())
                        .build();
            }
            return utilsComponent;
        }
}

What I want to know is that is this the right way to do this? Can it cause problems? If so, what are those?

Answer 1

It is ok, but you will not be able to use inject Context- dependent objects in that way. For component, requiring Context, use non - static accessor in Application class. Speaking more widely, there will be as many components as your want, but if if component provides @Singleton - annotated functionality, lifecycle of component should not be longer that one of feature using it.

Answer 2

It's okayish. But why would you put it in the Application class? Put it in standard singleton class called for example Injector . Still you might want to initialize that singleton in Application which is fine.