connection.connect（）第一次调用时花费的时间太长

Question

我正在尝试从多个URL获取位图。我正在使用以下代码。

Bitmap getBitmapFromUrl(String src){

            try{

                URL url = new URL(src);
                Log.d(TAG, "bitmap url is : " + url);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                Log.d(TAG, "getBitmapFromUrl1: ");
                connection.setDoInput(true);
                Log.d(TAG, "getBitmapFromUrl2: ");
                connection.connect();
                Log.d(TAG, "getBitmapFromUrl3: ");
                InputStream inputStream = connection.getInputStream();
                Log.d(TAG, "getBitmapFromUrl4: ");

                return BitmapFactory.decodeStream(inputStream);

            }catch (Exception e){

                Log.e(TAG, "getBitmapFromUrlException " + e );
                return null;

            }

        }

但是第一次调用connection.connect()时执行时间太长。我在AsyncTask类中使用此代码。