Gson fromJson() returns object with null attrubutes

Question

I\'m trying to create some Java objects using this line:

Quiz currentQuiz = gson.fromJson(json, Quiz.class);

But the all I get is this:

Answer 1

Try this...

JSONObject js = new JSONObject(jsonString);
for (int i = 0; i < js.length(); i++) {
  JSONObject quiz = js.getJSONObject("quiz");
    for (int j = 0; j < js.length(); j++) {
       String broadcast_dt = quiz.getString("broadcast_dt");
       String ref = quiz.getString("ref");
       JSONArray questions = quiz.getJSONArray("questions");
       for (int k = 0; k < questions.length(); k++) {
        String value = questions.getString(k);
        JSONObject quest = new JSONObject(questions.getString(k));
        int question_number = quest.getInt("question_number");
        String question_text = quest.getString("question_text");
        JSONArray answers = quest.getJSONArray("answers");
        for (int m = 0; m < answers.length(); m++) {
            JSONObject ans = new JSONObject(answers.getString(m));
            Boolean correct_yn = ans.getBoolean("correct_yn");
            String answer_text = ans.getString("answer_text");
        }
    }

}

}

Answer 2

From your json: i see that, at the root level it is something like

{quiz:{quizObject having ref,etc.,}}

So, you need to get one level down to start parsing using gson.

So, try this out,

JSONObject quizObject = json.get("quiz");

Quiz currentQuiz = gson.fromJson(quizObject.toString(), Quiz.class);

Answer 3

In my case I had deleted

@SerializedName("OpCode")
@Expose

parts from my model class which are above the

private Integer opCode;

line. And so Gson could not parse it and so my attributes were null. When I added those lines it fixed.