Android通知图片有时不显示

Question

我已经编码为从亚马逊获取图像并在通知的扩展视图中显示。下面是代码

         try { 
               URL url = new URL(imageUrl);            
               HttpURLConnection connection = (HttpURLConnection) url.openConnection();    
               connection.setDoInput(true);           
               connection.connect();         
               InputStream input = connection.getInputStream();           
               return BitmapFactory.decodeStream(input);
           } catch (Exception e) {
               // TODO Auto-generated catch block
               e.printStackTrace();      
               return null;
           }

相同的代码可以正常工作，并且在某些设备中显示图像，而不是同时在其他设备中显示图像。 未显示图像的异常如下所示

 java.net.UnknownHostException: Unable to resolve host 
"examples3.s3.amazonaws.com": No address associated with hostname

 java.net.ConnectException: Failed to connect to 
 examples3.s3.amazonaws.com/1.2.3.4:5(some ip showing, this is for the only 
 reference)