Question

I am using the code below in asyn task to download a bitmap to be added to my custom class. however sometimes it return nulls with no IOException or any exception. i am not very sure what can be done

    public  Bitmap downloadFile(String fileUrl){
    URL myFileUrl =null;          
    try {
        myFileUrl= new URL(fileUrl);
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    try {
        HttpURLConnection conn= (HttpURLConnection)myFileUrl.openConnection();
        conn.setDoInput(true);
        //conn.setReadTimeout(500000000);
        conn.connect();
        InputStream is = conn.getInputStream();
           BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(is, null, o);
        is.close();
        conn.disconnect();
        int scale = 1;
        int IMAGE_MAX_SIZE=400;
        if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) {
            scale = (int)Math.pow(2, (int) Math.round(Math.log(IMAGE_MAX_SIZE / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5)));
        }
        //Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        conn= (HttpURLConnection)myFileUrl.openConnection();
        conn.setDoInput(true);
        //conn.setReadTimeout(500000000);
        conn.connect();
        is  =  conn.getInputStream();
       Bitmap b = BitmapFactory.decodeStream(is, null, o2);
       if (b==null)
           Log.e(Config.log_id, " Download image failed");
    return b;

    }

    catch (IOException e) {
        Log.e(Config.log_id, " Download image failed"+e.getMessage());
        e.printStackTrace();
    }
    return null;
}

Answer 1

I have run into this as well when using unbuffered variants of
stream readers when getting from urls.

The simple solution that worked for me was to use a BufferedHttpEntity to get the image data.

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.BufferedHttpEntity;

public static Bitmap decodeFromUrl(HttpClient client, URL url, Config bitmapCOnfig)
    {
        HttpResponse response=null;
        Bitmap b=null;
        InputStream instream=null;

        BitmapFactory.Options decodeOptions = new BitmapFactory.Options();
        decodeOptions.inPreferredConfig = bitmapCOnfig;
        try
        {
            HttpGet request = new HttpGet(url.toURI());
            response = client.execute(request);
            if (response.getStatusLine().getStatusCode() != 200)
            {
                MyLogger.w("Bad response on " + url.toString());
                MyLogger.w ("http response: " + response.getStatusLine().toString());
                return null;
            }
            BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(response.getEntity());
            instream = bufHttpEntity.getContent();

            return BitmapFactory.decodeStream(instream, null, decodeOptions);
        }
        catch (Exception ex)
        {
            MyLogger.e("error decoding bitmap from:" + url, ex);
            if (response != null)
            {
                MyLogger.e("http status: " + response.getStatusLine().getStatusCode());
            }
            return null;
        }
        finally
        {
            if (instream != null)
            {
                try {
                    instream.close();
                } catch (IOException e) {
                    MyLogger.e("error closing stream", e);
                }
            }
        }
    }