I have implemented android app which should download images from server and display them in ListView, but very interesting thing occures while images are downloading

As you can see in video pictures which haven't been downloaded yet are represented by those which have been already downloaded. How that can happen? I've thinking about it almost two days.

<http://www.youtube.com/watch?v=lxY-HAuJO0o&feature=youtu.be>

here is my code of ListView adapter.

```
public class MoviesAdapter extends ArrayAdapter<ParkCinema> {
        private ArrayList<ParkCinema> movieDataItems;   
        private Activity context;

        public MoviesAdapter(Activity context, int textViewResourceId, ArrayList<ParkCinema> movieDataItems) {
            super(context, textViewResourceId, movieDataItems);
            this.context = context;
            this.movieDataItems = movieDataItems;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) { 
            if (convertView == null) {
                LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = vi.inflate(R.layout.movie_data_row, null);
                }

            ParkCinema movie = movieDataItems.get(position);

            if (movie!=null){
                        ImageView imageView = (ImageView) convertView.findViewById(R.id.movie_thumb_icon);
                        String url = movie.poster();

                         if (url!=null) {
                            Bitmap bitmap = fetchBitmapFromCache(url);
                            if (bitmap==null) { 
                                new BitmapDownloaderTask(imageView).execute(url);
                            }
                            else {
                                imageView.setImageBitmap(bitmap);
                            } 
                        } 
            }
            return convertView;
        }

        private LinkedHashMap<String, Bitmap> bitmapCache = new LinkedHashMap<String, Bitmap>();

        private void addBitmapToCache(String url, Bitmap bitmap) {
            if (bitmap != null) {
                synchronized (bitmapCache) {
                    bitmapCache.put(url, bitmap);
                }
            }
        }

        private Bitmap fetchBitmapFromCache(String url) {

            synchronized (bitmapCache) {
                final Bitmap bitmap = bitmapCache.get(url);
                 if (bitmap != null) {
                    return bitmap;
                } 
            }

            return null;

        }

    private class BitmapDownloaderTask extends AsyncTask<String, Void, Bitmap> {

            private String url;
            private final WeakReference<ImageView> imageViewReference;

            public BitmapDownloaderTask(ImageView imageView) {
                imageViewReference = new WeakReference<ImageView>(imageView);
            }

            @Override
            protected Bitmap doInBackground (String... source) {
                url = source[0];
                Bitmap image;
                try{
                    image = BitmapFactory.decodeStream(new URL(url).openConnection().getInputStream());
                    return image;
                    }
                catch(Exception e){Log.e("Error", e.getMessage()); e.printStackTrace();}
                return null;
                } 

            @Override
            protected void onPostExecute(Bitmap bitmap) {       
                addBitmapToCache(url, bitmap);
                imageViewReference.get().setImageBitmap(bitmap);               
            }
        }
    }

```

Edit 3:

```
public View getView(int position, View convertView, ViewGroup parent) { 
    if (convertView == null) {
        LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
        convertView = vi.inflate(R.layout.movie_data_row, null);
        }
    ParkCinema movie = movieDataItems.get(position);
    ImageView imageView = (ImageView) convertView.findViewById(R.id.movie_thumb_icon);
    if (movie!=null){
                String url = movie.poster();

                    if (url != null) {
                        Bitmap bitmap = fetchBitmapFromCache(url);
                        if (bitmap == null) {
                            imageView.setImageResource(R.drawable.no_image);
                            new BitmapDownloaderTask(imageView).execute(url);
                        }
                        else {
                            imageView.setImageBitmap(bitmap);
                        }
                    }
                    else {
                        imageView.setImageResource(R.drawable.no_image);
                    }
                }
                else {
                    imageView.setImageResource(R.drawable.no_image);
                } 

    return convertView;

}

```