Opening an activity in Android without having to Reload it from scratch
Intent intent = new Intent(this,SecondActivity.class);
                startActivityForResult(intent, RESULT_OK);

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
       // When you are back from second Activity you are land here ..
       // do what ever you want to, without re Creating the this Activity
    }
}

Activity.this.dispatchKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK));