Android Architectura with MVP

androidMVP.java

// ----------------------------------------------------------
// VIEW
// ----------------------------------------------------------
// This class represents View layer and also Controller layer
// ----------------------------------------------------------

public interface MainView {
  
  void showMessage(String message);
  
  void isLoadingEnabled(boolean value);
  
}

public class MainActivity extends AppCompatActivity implements MainView {
  
  private Button loadButton;
  private TextView console;

  // Use your favorite DI framework to achieve this
  @Inject
  private MainPresenter mainPresenter;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mainPresenter.attachView(this);
    
    // show views
    setContentView(R.layout.some_layout_activity);
    loadButton = (Button) findViewById(R.id.load_button);
    console = (TextView) findViewById(R.id.console_view);
    
    // delegate everything to the controller layer!
    loadButton.setOnClickListener(view -> {
      mainPresenter.clickOnLoad();
    });
  }
  
  @Override
  public void isLoadingEnabled(boolean value) {
    runOnUiThread(() -> loadButton.setEnabled(value));
  }
  
  @Override
  public void showMessage(String message) {
    runOnUiThread(() -> console.setText(message));
  }
  
}

// ----------------------------------------------------------
// Presenter
// ----------------------------------------------------------

public interface MainPresenter {
  void attachView(MainView view);
  void clickOnLoad();
}

public class MainPresenterImpl implements MainPresenter {
  
  private final CloudApi cloudApi;
  private MainView mainView;
  
  public MainController(CloudApi cloudApi) {
    this.cloudApi = cloudApi;
  }
  
  @Override
  public void attachView(MainView view){
    mainView = view;
  }
  
  @Override
  public void clickOnLoad() {
    mainView.isLoadingEnabled(false);
    doOnBackgroundThread(() -> {
      // prepare cloudApi for something, prepare everything that model might need to work
      try {
        int downloadedData = cloudApi.downloadSomething();
        mainView.isLoadingEnabled(true);
      } catch(InterruptedException e) {
        mainView.showMessage(e.getMessage());
        return;
      }
      mainView.showMessage("DOWNLOADED: " + downloadedData + ", Click again!");
    });
  }
  
}

// ----------------------------------------------------------
// MODEL
// ----------------------------------------------------------
// Classes that represents the Model layer
// ----------------------------------------------------------

public interface CloudApi {  
  int downloadSomething() throws InterruptedException;
}

public class CloudApiImpl {
  
  @Override
  public int downloadSomething() throws Exception {  
    Thread.sleep(5 * 1000); // simulate downloading something
    return 5; 
  }
  
}