HttpURLConnection throws an exception

android.os.NetworkOnMainThreadException occurs because you are making a network call in your main UI thread. Use asynctask instead.

Asynctask documentation. http://developer.android.com/reference/android/os/AsyncTask.html .

Call AsyncTask in your user interface thread.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    new MyDownloadTask().execute();

}

class MyDownloadTask extends AsyncTask<Void,Void,Void>
{


    protected void onPreExecute() {
      //display progress dialog.

 }
    protected Long doInBackground(Void... params) {
          URL url = new URL("http://www.google.com");
          HttpURLConnection con = (HttpURLConnection) url.openConnection();
          con.setDoOutput(true);
          String responseMsg = con.getResponseMessage();
          int response = con.getResponseCode();
     return null;
 }



 protected void onPostExecute(VOid result) {
   // dismiss progress dialog and update ui
 }
}

: AsyncTask Thread Handler . AsyncTasks ( ). , API, java.util.concurrent pacakge, , ThreadPoolExecutor FutureTask.

asynctask robospice. https://github.com/octo-online/robospice.

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