orhanobut

// sender
public class LoginActivity extends Activity {
  void displayHome() {
    startActivity(HomeActivity.newIntent(this, user));
  }
}

// receiver
public class HomeActivity extends Activity {
  private static final String KEY_USER = "KEY_USER";

orhanobut

public class Constants {
  public static final String KEY_USER = "KEY_USER";
}

// sends the data
public class LoginActivity extends Activity {
  void displayHome() {
    Intent intent = new Intent(this, HomeActivity.class);
    intent.putExtra(Constants.KEY_USER, user);
    startActivity(intent);

orhanobut

// sends the data
public class LoginActivity extends Activity {
  void displayHome() {
    Intent intent = new Intent(this, HomeActivity.class);
    intent.putExtra(HomeActivity.KEY_USER, user);
    startActivity(intent);
  }
}

// gets the data

orhanobut

// sends the data
public class LoginActivity extends Activity {
  private static final String KEY_USER = "KEY_USER";
  
  void displayHome() {
    Intent intent = new Intent(this, HomeActivity.class);
    intent.putExtra(KEY_USER, user);
    startActivity(intent);
  }
}

orhanobut

public class MyFragment extends Fragment {
  
  private void init() {
    for (View view : views) {
      view.setBackgroundColor(Color.BLACK);
    }
  }
}

orhanobut

public class ShareAndImageActivity extends Activity {
  
  ImageHelper imageHelper;
  ShareHelper shareHelper;
  
  @Override public void onCreate(Bundle bundle){
    ...
    imageHelper.onCreate(bundle);
    shareHelper.onCreate(bundle);
  }

orhanobut

public class AccountActivity extends Activity {
  
  ImageHelper imageHelper;
  
  @Override public void onCreate(Bundle bundle){
    ...
    imageHelper.onCreate(bundle);
  }
  
  @Override public void onDestroy() {

orhanobut

public class ImageHelper {
  
  public void onCreate(Bundle bundle) {
    // init
  }
  
  public void onDestroy() {
    // release allocations
  }
  

orhanobut

public class ShareActivity extends Activity {
  
  @Override public void onCreate(Bundle bundle){
    // init
  }
  
  @Override public void onDestroy() {
    // release memory
  }
  

orhanobut

public class ProductActivity extends ImageActivity {
  
  @Override public void onCreate(Bundle bundle){
    // init
  }
  
  public void onAvatarClicked() {
    showGalery();
  }