Load C++ in Android Activity

MainActivity.java

public class MainActivity extends AppCompatActivity {

    // Used to load the 'calculator' cpp library on application startup.
    static {
        System.loadLibrary("calculator");
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ...
    }
}