@ActivityScreen public class SampleActivity extends Activity {

@ActivityArg
  long id;
  @ActivityArg
  String title;

@Override
  protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

// read fields annotated with @ActivityArg

SampleActivityScreen.inject(this);

  
}
 
}

public final class SampleActivityScreen {

  public final long id;

public final String title;

public SampleActivityScreen(long id, String title) {

this.id = id;

this.title = title;
  
}

public void open(Activity activity) {

Intent intent = toIntent(activity);

activity.startActivity(intent);

  
}

public void openForResult(Activity activity, int requestCode) {

Intent intent = toIntent(activity);

activity.startActivityForResult(intent, requestCode);

  
}

public Intent toIntent(Activity activity) {

Intent intent = new Intent(activity, SampleActivity.class);

Bundle bundle = new Bundle();

bundle.putLong("id", id);

bundle.putString("title", title);

intent.putExtras(bundle);

return intent;
  
}

public static void inject(SampleActivity activity) {

Bundle bundle = activity.getIntent().getExtras();

if (bundle == null) {

 throw new NullPointerException("SampleActivity has empty Bundle. Use open() or openForResult() to launch activity.");

}

checkArguments(bundle);

activity.id = bundle.getLong("id");

activity.title = bundle.getString("title");

  
}

private static void checkArguments(Bundle bundle) {

if (!bundle.containsKey("id")) {

 throw new IllegalStateException("Required argument id with key 'id' is not set");

}

if (!bundle.containsKey("title")) {

 throw new IllegalStateException("Required argument title with key 'title' is not set");

}

  
}
 
}

 new SampleActivityScreen(3, "Sample title").open(activity);