Question

I am writing a simple app on android to get the information of user who login the app throught Facebook. Here is my codes:

public class example extends Activity {

Facebook facebook = new Facebook("id");
AsyncFacebookRunner mAsyncRunner = new AsyncFacebookRunner(facebook);

private static final String TAG ="Debug";
private SharedPreferences mPrefs;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_example);
    /*
     * Get existing access_token if any
     */
    mPrefs = getPreferences(MODE_PRIVATE);
    String access_token = mPrefs.getString("access_token", null);
    long expires = mPrefs.getLong("access_expires", 0);
    if(access_token != null) {
        facebook.setAccessToken(access_token);
    }
    if(expires != 0) {
        facebook.setAccessExpires(expires);
    }

    /*
     * Only call authorize if the access_token has expired.
     */
    if(!facebook.isSessionValid()) {

        facebook.authorize(this, new String[] {"publish_stream","email","user_groups","read_stream","user_about_me","offline_access"}, new DialogListener() {
            @Override
            public void onComplete(Bundle values) {
                SharedPreferences.Editor editor = mPrefs.edit();
                editor.putString("access_token", facebook.getAccessToken());
                editor.putLong("access_expires", facebook.getAccessExpires());
                editor.commit();
            }

            @Override
            public void onFacebookError(FacebookError error) {}

            @Override
            public void onError(DialogError e) {}

            @Override
            public void onCancel() {}
        });
    }        
    Log.d(TAG, access_token);
    getInformation();
}

private void getInformation(){

    JSONObject json = null;

    try
    {
        Log.d("testing", "point1");
        String response = facebook.request("me");
        Log.d("testing", "point2");
        json = Util.parseJson(response);
        String id = json.getString("id");
        Log.d("testing", id);
    }
    catch (MalformedURLException e)
    {
        e.printStackTrace();
    }
    catch (JSONException e)
    {
        e.printStackTrace();
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
    catch (FacebookError e)
    {
        e.printStackTrace();
    }

}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    facebook.authorizeCallback(requestCode, resultCode, data);
}

@Override
public void onResume() {    
    super.onResume();
    facebook.extendAccessTokenIfNeeded(this, null);
}
}

I follow here https://developers.facebook.com/docs/mobile/android/build/#sdk and use the same facebook SDK. So as show on the code, in logcat there is only point1 but not point2, which means the facebook.request(“me”) is not success. The emulator shows the app shut down and say “unfortunately, example has stopped.”

So can anyone help me to point out the question? I wondering if the is something wrong in the access token but I dont know about it. Thanks a lot.

LogCat:

11-03 10:13:55.986: D/Debug(893): AAAFi20EvlJEBACwBLIR4buSOaZB1emxACFPZCZAKums6ZCNwZB0wZCvQnI3grshT0YNl8ZC427BSkrNye6akdCZBjvp4KL24Oyx......
11-03 10:13:55.986: D/testing(893): point1
11-03 10:13:56.106: D/AndroidRuntime(893): Shutting down VM
11-03 10:13:56.106: W/dalvikvm(893): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
11-03 10:13:56.136: E/AndroidRuntime(893): FATAL EXCEPTION: main
11-03 10:13:56.136: E/AndroidRuntime(893): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crush/com.example.crush.Crush}: android.os.NetworkOnMainThreadException
11-03 10:13:56.136: E/AndroidRuntime(893):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)

Answer 1

You’re running a network operation on main thread. Use async task to run network operations in background thread (do your http requests in a background thread). That’s why you are getting android.os.NetworkOnMainThreadException.

Do your networking in an async task like this:

class FacebookRequestTask extends AsyncTask{


    protected void onPreExecute() {
    //show a progress dialog to the user or something
    }

    protected void doInBackground() {
        //Do your networking here
    }

    protected void onPostExecute() {
        //do something with your parsed 
        //response (JSON data in case of facebook API's) here 
        // and dismiss the progress dialog
    }
  }

  new facebookRequestTask().execute();

Here are some tutorials for you if you don’t know how to use async tasks:

http://mobileorchard.com/android-app-developmentthreading-part-2-async-tasks/

http://www.vogella.com/articles/AndroidPerformance/article.html

Here are the official docs from Google:

https://developer.android.com/reference/android/os/AsyncTask.html