Automatically change images using fade animation

How to obtain the automatic change of the images with the fade animation?

public class MainActivity extends AppCompatActivity {

    public void fade (View view) {

        ImageView img1 = (ImageView) findViewById(R.id.img1);
        ImageView img2 = (ImageView) findViewById(R.id.img2);

        img1.animate().alpha(0f).setDuration(1000);
        img2.animate().alpha(1f).setDuration(1000);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (Build.VERSION.SDK_INT > 16) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                    WindowManager.LayoutParams.FLAG_FULLSCREEN);
        }

        setContentView(R.layout.activity_main);
    }
}