Fast method to download HTML in android?

Question

I am using AsyncTask to download a webpage source(HTML) . It is working properly but it take to long to execute .. is there a better method. I think It is wasting time in UrlConnection .I have tried to do this with HttpClient but can't get Html source. Help me out in making it fast or .. tell me how to put this AsyncTask in thread?

class RetrieveFeedTask extends AsyncTask<String, Void, String> 
{   
    @Override
    protected void onPreExecute() 
    {
        super.onPreExecute();

        Utilities.hideSoftKeyboard(PlayListActivity.this);

        progressDialog = ProgressDialog.show(PlayListActivity.this,
                "Loading...", "Please wait...");
    }

    @Override
    protected String doInBackground(String... urls) {
        try {
            URL url= new URL(urls[0]);

            URLConnection conn = url.openConnection();

            // open the stream and put it into BufferedReader
            BufferedReader br = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));

            String inputLine;
            String HTML_response = "";  
            while ((inputLine = br.readLine()) != null) {
                // System.out.println(inputLine);
                HTML_response += inputLine;
            }
            br.close();

            System.out.println("Done");
                            Parser(feed);

            return HTML_response;
        } /*catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }*/catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    @Override
    protected void onPostExecute(String feed)
    {
        super.onPostExecute(feed);

        PlayListAdapter adapter = new PlayListAdapter(
            PlayListActivity.this, list);

    list_of_songs.setAdapter(adapter);

        progressDialog.dismiss();
    }
}

@SuppressLint("NewApi")
void Parser(String x) 
{
    if (x.contains(spliter_start))
    {
        if (spliter_end.isEmpty())
        {
            x = x.substring(x.indexOf(spliter_start));
        }
        else
        {
            x = x.substring(x.indexOf(spliter_start),
                    x.indexOf(spliter_end));
        }

    }

    int i = 0;
    list.clear();
    while (x.contains(loop_controller))
    {
        if (i > 50)
        {
            break;
        }

        HashMap<String, String> map = new HashMap<String, String>();

        x = x.substring(x.indexOf(song_start));


        map.put("songsName",x.substring(
                x.indexOf(song_start) + song_start.length(),
                x.indexOf(song_end)));// songsName.get(i));

        x = x.substring(x.indexOf(song_url_start));

        map.put("songsUrl",x.substring(
                x.indexOf(song_url_start) + song_url_start.length(),
                x.indexOf(song_url_end)));// songsUrl.get(i));


        list.add(map);

        i++;
    }



}

Answer 1

This part:

    String inputLine;
    String HTML_response = "";  
    while ((inputLine = br.readLine()) != null) {
        // System.out.println(inputLine);
        HTML_response += inputLine;
    }

Is insane - you should never do things like that with Strings as on every single iteration of the loop new String is created. User StringBuilder.append(); instead String HTML_response

Answer 2

First of all, AsyncTasks already run in a separate thread, so you don't have to worry about that here. Second all AsyncTasks must perform their long-time operations in the doInBackground method since is here where the thread runs, so your problem here is that you're calling your parser in the onPostExecute method. You could change it to this (assuming that your object list is a global variable:

@Override 
protected String doInBackground(String... urls) {
    (...)

        System.out.println("Done");

        return Parser(HTML_response);
    (..)
} 

@Override 
protected void onPostExecute(Void void)
{ 
    super.onPostExecute(feed);

    PlayListAdapter adapter = new PlayListAdapter(
        PlayListActivity.this, list); 

    list_of_songs.setAdapter(adapter);

    progressDialog.dismiss(); 
} 
} 

About the download code I think it's ok and I don't really know if it could be more efficient.

Hope that helps, greetings!