Solved. Change the code to this.
@Override
protected Bitmap doInBackground(String... params) {
// TODO Auto-generated method stub
String urlStr = params[0];
Bitmap img = null;
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(urlStr);
HttpResponse response;
try {
response = (HttpResponse)client.execute(request);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufferedEntity = new BufferedHttpEntity(entity);
InputStream inputStream = bufferedEntity.getContent();
img = BitmapFactory.decodeStream(inputStream);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return img;
}