Android - Load Images from URL

In this Android tutorial you will learn to load images from URL. To connect android application with server we need to create a background thread. 

To load image from server we are going to implement our own background task using AsynchTask. Then we will get the image as a bitmap. After that we will load that image on our ImageView.

Create a subclass of AsynchTask

To allow network operation in different thread we are using AsynchTask. Follow the instructions given below  to implement your custom AsynchTask.

1 2	public class LoadImage extends AsyncTask<String, Void, Bitmap>{ }

1. Include the source of image file by providing URI of the resource.

   1	String src = "http://www.example.com/kb4dev-remoteimage.jpg";

2. Create a URL object which represents an absolute url.
   1	URL url = new URL(src);

3. HttpURLConnection helps to send and receive data over the web.
   url.openConnection() returns a new connection to the resource at url.
   1	HttpURLConnection connection = (HttpURLConnection) url.openConnection();

4. Open the connection to resource using connect().
   1	connection.connect();

5. Convert data into bitmap. We need to fetch the inputstream first. Then we decode it to Bitmap object.
   1 2	InputStream input = connection.getInputStream(); Bitmap myBitmap = BitmapFactory.decodeStream(input);

6. Get the reference of ImageView in order to diplay image on it.
   1	ImageView imageView = (ImageView) viewItem.findViewById(R.id.imageView);

7. Set bitmap as a resource on ImageView.
   1	ImageView imageView = (ImageView) viewItem.findViewById(R.id.imageView);

Full implementation of AsynchTask

Below code snippet can be used to get image from server. Make sure you edit the URL according to location of your image file.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

public class LoadImage extends AsyncTask<String, Void, Bitmap>{                   @Override         protected Bitmap doInBackground(String... params) {             // TODO Auto-generated method stub             String src = "http://www.example.com/kb4dev-remoteimage.jpg";             try {                 URL url = new URL(src);                 HttpURLConnection connection = (HttpURLConnection) url.openConnection();                 connection.setDoInput(true);                 connection.connect();                 InputStream input = connection.getInputStream();                 Bitmap myBitmap = BitmapFactory.decodeStream(input);                 return myBitmap;             } catch (MalformedURLException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             } catch (IOException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }             return null;         }         @Override         protected void onPostExecute(Bitmap result) {             // TODO Auto-generated method stub             super.onPostExecute(result);                                       ImageView imageView = (ImageView) viewItem.findViewById(R.id.imageView);                         imageView.setImageBitmap(bitmapList);         }                                   }

Output: