How to work Backpressed on android.txt

// In this code, android lifecycle exit on 2 times back-pressed. 
    @Override
    public void onBackPressed() {

        if (pressedTime + 2000 > System.currentTimeMillis()) {
            super.onBackPressed();
            finish();
        } else {
            Toast.makeText(getBaseContext(), "Press back again to exit", Toast.LENGTH_SHORT).show();
        }
        pressedTime = System.currentTimeMillis();
    }