Solving Android NetworkOnMainThreadException with AsyncTask

Starting from Android Honeycomb, you must not do networking on the Main Thread. Break this rule and you’ll get an error like this!

android.os.NetworkOnMainThreadException

For example, running the method below throws a NetworkOnMainThreadException.

// old code raising error
public HttpResponse getResponse(String url) {
  try {
    HttpGet request = new HttpGet(url);
    HttpResponse response = new DefaultHttpClient().execute(request); // raise error!
    return response;
  }
  catch (Exception e) {
    // android.os.NetworkOnMainThreadException!
  }
}

This is meant to prevent the app from freezing because everything is being run on the main thread.

To solve this, you can use AsyncTask. There’s no need to create a new thread yourself. I put together a simple example.

// Use AsyncTask and no error!
public HttpResponse getResponse(String url) {
  try {
    AsyncTask<String, Void, HttpResponse> asyncTask = new AsyncTask<String, Void, HttpResponse>() {
      @Override
      protected HttpResponse doInBackground(String... url) {
        HttpGet request = new HttpGet(url[0]);
        HttpResponse response = null;
        try {
          response = new DefaultHttpClient().execute(request);
        } catch (IOException e) {
          e.printStackTrace();
        }
        return response;
      }
    };

    HttpResponse response = asyncTask.execute(url).get();
    return response;
  }
  catch (Exception e) {
    // No error
  }
}

Use AsyncTask to handle inter-thread communication with ease!