must implement method doInBackground (params) <p>I have a class extending AsyncTask which has to implement doInBackground method. I have the method defined below , still I have an error saying the class has to implement method.</p> <pre><code>public class MyDownloadJsonAsyncTask extends AsyncTask&lt;Void , String, Bitmap&gt; { private final WeakReference&lt;RecyclerView_Adapter&gt; adapterReference; MovieDataJson movieData; public MyDownloadJsonAsyncTask(RecyclerView_Adapter adapter) { adapterReference = new WeakReference&lt;RecyclerView_Adapter&gt;(adapter); } @Override protected MovieDataJson doInBackground(String... urls) { MovieDataJson threadMovieData = new MovieDataJson(); for (String url : urls) { threadMovieData.downloadMovieDataJson(url); } return threadMovieData; } @Override protected void onPostExecute(MovieDataJson threadMovieData) { movieData.moviesList.clear(); for(int i=0;i&lt;threadMovieData.getSize();i++) { movieData.moviesList.add(threadMovieData.moviesList.get(i)); } if(adapterReference!=null) { final RecyclerView_Adapter adapter= adapterReference.get(); if(adapter!=null) adapter.notifyDataSetChanged(); } } </code></pre> <p>}</p> <p>and at @Override for each method above says method does not override method from its superclass</p>