“language”: { 
“q”: “Q”, 
“a”: “A” 
}

JSONObject language = obj.optJSONObject("language");
if(language !=null ){
  try {
    HashMap<String,String> nickname = new Gson().fromJson(language.toString()
    , new TypeToken<HashMap<String, String>>(){}.getType());
  }catch (Exception e){
    HashMap<String,String> nickname = null;
  }
}

 Map<String, Number> map = new HashMap<String, Number>();  
  map.put("int", 123);
  map.put("long", 1234567890123456789L);
  map.put("double", 1234.5678D);
  map.put("float", 1.2345F);
  Type mapType = new TypeToken<Map<String, Number>>() {}.getType();
  Gson gson = new GsonBuilder().registerTypeAdapter(Number.class
  , new NumberTypeAdapter()).create();
  String json = gson.toJson(map, mapType);