Access to the values in a multi-level JSON-structure

Question

There is my JSON-structure:

{
   "date":"19.11.2013",
   "parent":{
      "child1":[
         {
            "date":"2013-11-19",
            "time":"10:30",
         },
         {
            "date":"2013-11-19",
            "time":"12:20",
         }
      ],
      "child2":[
         {
            "date":"2013-11-19",
            "time":"10:30",
         },
         {
            "date":"2013-11-19",
            "time":"12:20",
         }
      ]
   }
}

And it's my code at the moment:

public class json {
    public static void main(String[] args) throws IOException, ParseException {

        URL urlData = new URL("http://path.to/json");
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                urlData.openConnection().getInputStream(), "utf-8"));
        String struct = reader.readLine();

        JSONParser parser = new JSONParser();
        Object obj = parser.parse(struct);
        JSONObject lev1 = (JSONObject) obj;
        System.out.println(lev1.get("date"));
    }
}

I got a date value (19.11.2013), but I don't know how to get child's values of date and time. I'm using json-simple library.

According to http://jsonlint.com/ the posted JSON is not valid. Maybe you want to fix that first (or possible copy/paste errors here). — Marcel Stör, Nov 19 '13 at 20:08
It is always easier and recommended to parse JSON in clientside — Suganthan Madhavan Pillai, Nov 20 '13 at 05:03
@MarkKorzhov and your json having error SyntaxError: Unexpected token o — Suganthan Madhavan Pillai, Nov 20 '13 at 05:05

score 5 · Accepted Answer · answered Nov 19 '13 at 20:14

Here is the idea :

JSONObject parent = (JSONObject) lev1.get("parent");
JSONArray child1 = (JSONArray) parent.get("child1"); // same for child2
for (Object elem : child1) {
    System.out.prinlnt("date =  " + ((JSONObject) elem).get("date"));
    System.out.prinlnt("time =  " + ((JSONObject) elem).get("time"));
}

Let me know if it does not compile, otherwise should work.

score 1 · Answer 2 · answered Nov 20 '13 at 05:00

Since, the names of the array are child1 and child2 (which means the names are different), inside the parent object , first you have to fetch these names, and then for each array, fetch date and time.

Here struct , is the jsonString:

        JSONParser parser = new JSONParser();
        Object obj = parser.parse(struct);
        JSONObject lev1 = (JSONObject) obj;
        Object jObj = lev1.get("parent");
        List keys = new ArrayList();
        if (jObj instanceof Map) {
            Map map = (Map) jObj;
            Set keySet = map.keySet();
            for (Object s : keySet) {
                JSONObject jsonObj = (JSONObject) jObj;
                JSONArray jarr = (JSONArray) jsonObj.get(s.toString());
                for (int i = 0; i < jarr.size(); i++) {
                    Object get = jarr.get(i);
                    JSONObject job = (JSONObject) get;
                    String date = job.get("date").toString();
                    String time = job.get("time").toString();
                    System.out.println("Date: " + date + " , Time: " + time);
                }
            }
        }

Access to the values in a multi-level JSON-structure

2 Answers2