O código

URL url = new URL(bitmapurl);

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
     connection.setDoInput(true);
      connection.connect();
 InputStream input = connection.getInputStream();

bitmap[i] = BitmapFactory.decodeStream(input);
System.out.println("the bitmap is +bitmap[i]);

Erro no Logcat:

03-29 15:01:50.044: DEBUG/skia(238): --- SkImageDecoder::Factory returned null
the bitmap is null

Como esse problema pode ser resolvido