Here I have built up the JSONObject manually for you:
try{
JSONObject attr1 = new JSONObject("{\"id\": 1, \"level\":3 }");
JSONArray sports = new JSONArray();
sports.put(attr1);
//sports.put(attr2); and so on
JSONObject yourObject = new JSONObject("{\"about\": \"About me\"}");
yourObject.put("sports", sports);
String url = yourObject.toString();
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse httpResponse = httpclient.execute(httppost);
}catch(Exception e){
}
As you can see, I have built some parts of the json from string, but you can create also an empty object and fill it with data ( as I did in the case of the jsonarray )