JSONArray dateArray = new JSONArray();
        JSONObject json = new JSONObject();
        String policyNos=test();
        
        json = JSONObject.fromObject(policyNos);

        String arr=json.getString("policyNos");
        dateArray=JSONArray.fromObject(arr);
        for (Object object : dateArray)
        {
            json=(JSONObject) object;
           System.out.println(object);
        }
        Iterator keys = json.keys();
        //然后通过一个循环取出所有的key值
        while (keys.hasNext()){
            String key = String.valueOf(keys.next());
            System.out.println(key);
            //最后就可以通过刚刚得到的key值去解析后面的json了
        }