JSON from String Builder (Java) - null error

Question

I am building a program using a GET API call to pull artist info in an Eclipse/Java console. I get a good connection to the API that prints out JSON but I'm getting error when trying to pull a specific data point: Cannot invoke "org.json.simple.JSONObject.get(Object)" because "nbalbum" is null

I'm very new to Java and JSON so appreciate pointers here.

Here is my code below with an example JSON return at bottom:

    public static void main(String[] args) {

        {   
        
    }
            
        try {
            //scanner for artist name user input in console
            Scanner artistscan = new Scanner(System.in); //create scanner
            System.out.println("Please enter artist name to search:"); 
            String artistname = artistscan.nextLine(); //turn input into string
            System.out.println("Here is how many albums this artist has:");
                artistscan.close(); 
     
                 String oldurl = "https://api.deezer.com/search/artist?q="
                        +artistname+"";
            String newurl=oldurl.replaceAll(" ", "");
            URL url = new URL(newurl);
    
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.connect();

            //Check if connect is made
            int responseCode = conn.getResponseCode();

            // 200 OK
            if (responseCode != 200) {
                throw new RuntimeException("HttpResponseCode: " + responseCode);
              
            } else {

                StringBuilder informationString = new StringBuilder();
                
                Scanner scanner = new Scanner(url.openStream());
           
                while (scanner.hasNext()) {
                    informationString.append(scanner.nextLine());
                }
                //Close the scanner
                scanner.close();
                //print results
              System.out.println(url); //test url is built correctly
                System.out.println(informationString);
            
                      
    //Parse JSON results....  
  //    error/returns null:
    org.json.simple.parser.JSONParser jsonParser = new JSONParser();
    org.json.simple.JSONObject jsonObj = new JSONObject();
    jsonObj = (JSONObject) jsonParser.parse(String.valueOf(informationString));
  JSONObject nbalbum = (JSONObject) jsonObj.get(0);
     System.out.println(nbalbum.get("nb_album"));            
   
     
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    
    System.out.println("-------------------------------------");
         }}

This is an example JSON return:

{"data":[{"id":566,"name":"Foo Fighters","link":"https:\/\/www.deezer.com\/artist\/566","picture":"https:\/\/api.deezer.com\/artist\/566\/image","picture_small":"https:\/\/e-cdns-images.dzcdn.net\/images\/artist\/54c324b8651addd8c400de22f9dac5c8\/56x56-000000-80-0-0.jpg","picture_medium":"https:\/\/e-cdns-images.dzcdn.net\/images\/artist\/54c324b8651addd8c400de22f9dac5c8\/250x250-000000-80-0-0.jpg","picture_big":"https:\/\/e-cdns-images.dzcdn.net\/images\/artist\/54c324b8651addd8c400de22f9dac5c8\/500x500-000000-80-0-0.jpg","picture_xl":"https:\/\/e-cdns-images.dzcdn.net\/images\/artist\/54c324b8651addd8c400de22f9dac5c8\/1000x1000-000000-80-0-0.jpg","nb_album":37,"nb_fan":4040577,"radio":true,"tracklist":"https:\/\/api.deezer.com\/artist\/566\/top?limit=50","type":"artist"}],"total":1}

Answer 1

Isn't the JSONObject you're getting, have data field & against this field you have JSON array as value. So if this is true, then maybe fetching json array by jsonObj.get("data") & then accessing the value at a certain position would probably work.