Migrating One Android JSON App Into a simple app in Android
It is recommended to use AsyncTask for network operations.Prior to Honey Comb it won't give any error but from HoneyComb version network operations on Main UI thread will result in NetworkOnUIthread exception.
So Call your : JSONObject json = jParser.getJSONFromUrl(url); to doInBackGround() method of async task and update your UI with the results in OnPostExecute Method.
From your logcat
11-22 12:10:56.958: E/AndroidRuntime(381): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.assent.app/com.example.assent.app.AndroidJSONParsingActivity}: android.os.NetworkOnMainThreadExceptionYou are downloading your json on the main thread, wich throws and exception on Android 3.0+.
The specific line is this : JSONObject json = jParser.getJSONFromUrl(url);. Move it to another thread and it should fix your problem.