Question

Am having a problem reading/parsing the following JSON string in Java.

Code:

try{
  json = new JSONObject(result);
//json now looks like this :-
// {'header': '[{"doc_no": "DN00001","stage":"P"}]','section':'[{"upper":100,"lower":1]'}
  if (json != null){
     // this line is throwing an exception!!
     JSONObject header =  new JSONObject("header");
   }catch(JSONException e){
    // Error Message
}

I’ve also tried this:

JSONArray  header = json.getJSONArray("header");

but still throwing some exception.

What am I missing?

Answer 1

Here dude take this code. Fix your JSON string if you wanted to get JSONObject out of it

public static void main(String[] args) throws JSONException {
    String result = "{'header': '[{\"doc_no\": \"DN00001\",\"stage\":\"P\"}]','section':'[{\"upper\":100,\"lower\":1]'}";
    JSONObject json = new JSONObject(result);
    // json now looks like this :-
    //
    if (json != null) {
        String header = json.getString("header");
        System.out.println(header);
    }

}

So what’s wrong with you? Couple of things:

1. Your JSON string is all illegal. Thanks to parsers to bear with you. It should be

   {
     "header": [{"doc_no": "DN00001","stage":"P"}],
     "section":[{"upper":100,"lower":1]
   }
   

2. It wont solve your problem alone. Since you wanted to get JSONObject but you provided a JSONArray (why did you do that?). So remove those square brackets.

3. Still not happy. You see you are trying to create a new JSONObject by doing (obviously) new JSONObject("header") using a string taht is not a JSON. 9And expecting it not to throw error? How cruel.) Plus you wanted to get not set. So use json.getXXX("header") where XXX can be String, JSONObject or JSONArray and many more.