Map集合中嵌套list

        Map<String,Object> requestMap = new HashMap<String,Object>();
        List<Map<String,Object>> questionList = new ArrayList<Map<String,Object>>();
        Map<String,Object> questionMap =new HashMap<String,Object>();
        questionMap.put("answerId","1");
        questionMap.put("custom_answer","1");
        questionMap.put("id", "1");
        questionList.add(questionMap);
        requestMap.put("questionList", questionList);