Android: Bug with ThreadSafeClientConnManager downloading images

Question

For my current application I collect images from different "event providers" in Spain.

  Bitmap bmp=null;
  HttpGet httpRequest = new HttpGet(strURL);

  long t = System.currentTimeMillis();
  HttpResponse response = (HttpResponse) httpclient.execute(httpRequest);
  Log.i(TAG, "Image ["+ strURL + "] fetched in [" + (System.currentTimeMillis()-t) + "ms]");

     HttpEntity entity = response.getEntity();
     InputStream instream = entity.getContent();
     bmp = BitmapFactory.decodeStream(instream);

     return bmp;

However, when downloading images from salir.com I get the following logcat output:

13970     Gallery_Activity  I  Fetching image 2/8 URL: http://media.salir.com/_images_/verticales/a/0/1/0/2540-los_inmortales_la_trattoria-marc_aureli_27_29_no.jpg
13970     ServiceHttpRequest  I  Image [http://media.salir.com/_images_/verticales/a/0/1/0/2540-los_inmortales_la_trattoria-marc_aureli_27_29_no.jpg] fetched in [146ms]
13970     skia  D  --- decoder->decode returned false

A search for that error message didn't provide much useful results.

Anyone an idea what the problem could be?

Gracias!

---

Update 1:

After inquiring a bit more and testing different stuff I figured out that the problem seems to lie somewhere else. Even though my logcat output says

13970     ServiceHttpRequest  I  Image [http://media.salir.com/_images_/verticales/a/0/1/0/2540-los_inmortales_la_trattoria-marc_aureli_27_29_no.jpg] fetched in [146ms]
getContentLength(): 93288

which is the correct length of the image in bytes it seems that there's something wrong with the stream or HTTP connection.

My original code (above) is taking advantage of the ThreadSafeClientConnManager. If I replace it with just a simple URLConnection it works perfectly:

URL url = new URL(strURL);
URLConnection conn = url.openConnection();
conn.connect();
InputStream instream = conn.getInputStream();
bmp = BitmapFactory.decodeStream(instream);

So, I'm wondering now why does my ThreadSafeClientConnManager work flawlessly (at least it seems it does) with all my other connections (mostly exchanging JSONObjects) but not with images from some specific websites (e.g. salir.com - for most other websites it works, though). Is there a HTTP parameter I'm missing?

My current setup is:

HttpParams parameters = new BasicHttpParams();
HttpProtocolParams.setVersion(parameters, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(parameters, HTTP.UTF_8);
HttpProtocolParams.setUseExpectContinue(parameters, false); // some webservers have problems if this is set to true
ConnManagerParams.setMaxTotalConnections(parameters, MAX_TOTAL_CONNECTIONS);
HttpConnectionParams.setConnectionTimeout(parameters, CONNECTION_TIMEOUT);
HttpConnectionParams.setSoTimeout(parameters, SOCKET_TIMEOUT);

SchemeRegistry schReg = new SchemeRegistry();
schReg.register(new Scheme("http", 
     PlainSocketFactory.getSocketFactory(), HTTP_PORT));

ClientConnectionManager conMgr = new ThreadSafeClientConnManager(parameters,schReg);

DefaultHttpClient http_client = new DefaultHttpClient(conMgr, parameters);

---

Update 2:

Now, the strange thing is, that it actually does work with the ThreadSafeClientConnManager -sometimes-. If I keep trying downloading the image and decoding it for a couple of times in a row it might work after 15-30 trials. Very strange.

I hope there's a solution to that since I would prefer using the ThreadSafeClientConnManager instead of URLConnection.

---

Update 3:

As suggest by Mike Mosher below, it seems that by using BufferedHttpEntity the decoding error doesn't appear any more. However now, even though less often than before, I get a SkImageDecoder::Factory returned null error.

Answer 1

Stefan,

I've had the same issue, and didn't find much searching the internet. Many people have had this issue, but not alot of answers to solve it.

I was fetching images using URLConnection, but I found out the issue doesn't lie in the download, but the BitmapFactory.decodeStream was having an issue decoding the image.

I changed my code to reflect your original code (using httpRequest). I made one change, which I found at http://groups.google.com/group/android-developers/browse_thread/thread/171b8bf35dbbed96/c3ec5f45436ceec8?lnk=raot (thanks Nilesh). You need to add "BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity); "

Here was my previous code:

        conn = (HttpURLConnection) bitmapUrl.openConnection(); 
        conn.connect();
        is = conn.getInputStream();
        //bis = new BufferedInputStream(is);
        //bm = BitmapFactory.decodeStream(bis);
        bm = BitmapFactory.decodeStream(is);

And her is the code that works:

            HttpGet httpRequest = null;

    try {
        httpRequest = new HttpGet(bitmapUrl.toURI());
    } catch (URISyntaxException e) {
        e.printStackTrace();
    }

    HttpClient httpclient = new DefaultHttpClient();
        HttpResponse response = (HttpResponse) httpclient.execute(httpRequest);

        HttpEntity entity = response.getEntity();
        BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity); 
        InputStream instream = bufHttpEntity.getContent();
        bm = BitmapFactory.decodeStream(instream);

As I said, I have a page that download around 40 images, and you can refresh to see the most recent photos. I would have almost half fail with the "decoder->decode returned false error". With the above code, I have had no problems.

Thanks

Answer 2

My solution is not to use BitmapFactory.decodeStream() cause the way I look at it, it uses the SKIA decoder and it seems kind of erratic sometimes. You can try something like this.

    Bitmap bitmap = null;
    InputStream in = null;
    BufferedOutputStream out = null;
    try {
            in = new BufferedInputStream(new URL(url).openStream(),
                     IO_BUFFER_SIZE);

            final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
            out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
            copy(in, out);
            out.flush();

            final byte[] data = dataStream.toByteArray();
            bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);


   } catch (......){

   }        

and for the copy() function

private static void copy(InputStream in, OutputStream out) throws IOException {
    byte[] b = new byte[IO_BUFFER_SIZE];
    int read;
    while ((read = in.read(b)) != -1) {
        out.write(b, 0, read);
    }
}

and IO_BUFFER_SIZE is a constant integer with the value of 4 * 1024.

Answer 3

This is a Android bug. Your code is ok. "Android's decoders do not currently support partial data on decode." If you got image in entity probably it's a partial input stream, and android can't cope with that at the moment.

Solution is to use FlushedInputStream from this thread: http://code.google.com/p/android/issues/detail?id=6066