Saving data in activity instance state

MainActivity.java

/**
 * When the user changes orientation in the activity, the activity is redrawn.
 * To prevent loss of my variables (like what question is active) I save a variable into
 * the instance state of my activity.
 * When this is done, I can prevent the user fron detecting the redraw of my activity.
 */
public class MainActivity extends Activity {

    // My variable I want to keep.
    public int currentQuestionNumber = 0;
    // Label for my variable; used when saving to instance state.
    private static final String CURRENT_QUESTION = "current_question";

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        // My onCreate method in my activity ...

        // Check if state is already set.
        if (savedInstanceState != null) {
            // If saved state exists, then get the variable from instance state.
            currentQuestionNumber = savedInstanceState.getInt(CURRENT_QUESTION);
        }
    }

    // ...

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        // When the user changes orientation, this is run.

        // Save variable to instance state.
        outState.putInt(CURRENT_QUESTION, currentQuestion);
    }
}