Networking Android Club 2015

Networking AsyncTask HttpUrlConnection JSON Parser

Thread UI thread Background thread

AsyncTask Helps us to manage process of backgroud thread Started from UI thread

AsyncTask: 3 parameters 1. Params 2. Progess 3. Result

AsyncTask: example TimeUnit.SECONDS.sleep(10);

AsyncTask: practice Create public static ProgressDialog in Activity Create AsyncTask onPreExecute: set message to dialog onPreExecute: show progress dialog onPostExecute: dismiss dialog

AsyncTask: pass data HttpTask task = new HttpTask(); task.execute(3); TimeUnit.SECONDS.sleep(params[0]);

Pass data: practice Change previous code so that it should wait twice amount of time If you pass 3, it should wait 6 seconds If 10, then 20

Networking: easiest way 1.Add permission: INTERNET 2.Create AsyncTask 3. Create HttpUrlConnection 4. Convert InputStream to String 5. Update UI 6. Start from UI

Step 1: Add permission Open AndroidManifest.xml Add this permission:

Step 2: Create AsynkTask public class HttpTask extends AsyncTask protected String doInBackground(String... params) { return null; protected void onPostExecute(String s) { } }

Step 3: HttpUrlConnection URL url = new URL(params[0]); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.connect();

Step 4: InputString to String InputStream stream = connection.getInputStream(); InputStreamReader isReader = new InputStreamReader(stream ); BufferedReader buffer = new BufferedReader(isReader ); StringBuilder content = new StringBuilder(); String line; while ((line = buffer.readLine()) != null) { content.append(line); }

Step 5: Update UI MainActivity.tvData.setText(s);

Step 6: Start from UI HttpTask task = new HttpTask(); String url = " task.execute(url);

HttpUrlConnection: practice 1.Create new AsyncTask 2. Get content using HttpUrlConnection 3. Convert content InputStream to String 4. Update UI 5. Pass that URL to AsyncTask

Parsing JSON: example JSONObject object = new JSONObject(s); String ip = object.getString("ip"); MainActivity.tvData.setText("My ip address is "+ip);

Parsing JSON: practice OUR_IP Show latitude Show longitude Show ISP Show country

Homework 1: Forecast.IO developer.forecast.io

Homework 2: Football- api.com Demo - EPL Free English Premier League Access limit: 1000 requests per hour Access from 1 IP address

Homework 3: Your own API Create your own API For example: calculator for communal services