So basicly am trying to use dagger to inject a Baz field into class Foo, it goes like this
Baz.java
public class Baz {
}
Foo.java
public class Foo {
@Inject Baz baz;
}
but nothing gets injected and baz still null when i run it, i even tried to write the Baz empty constructor and annotate it with @Inject but it doesn't work either
how dagger work is it able to see all my classes so when i request a class instance he can create one, or am i missing some annotation, or even worse my annotation processor not working. i added those dependencies to my app.gradle
implementation 'com.google.dagger:dagger:2.14.1'
annotationProcessor 'com.google.dagger:dagger-compiler:2.14.1'
If you want to inject something somewhere using Dagger2, it's essential to have a component, also you need a place, where you want to have Foo object (which has a Baz object itself). In addition to this, you should specify the way, how objects should be created by dagger2. In your case constructor injection is absolutely OK.
Let's assume, that our component is TestComponent and the place, where we want to have Foo object is MainActivity, then the code would be something like this:
Baz.java
public class Baz {
@Inject
public Baz() {
}
}
Foo.java
public class Foo {
@Inject
Baz baz;
@Inject
public Foo() {
}
}
TestComponent.java
@Component
public interface TestComponent {
void inject(MainActivity injector);
}
(When you create component, rebuild the project)
MainActivity.java
public class MainActivity extends AppCompatActivity {
@Inject
Foo foo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DaggerTestComponent.builder().build().inject(this);
}
}
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