Read properties of array of json objects in a json file in java

Question

I am new to JSON array/objects in the java. Here I am struggling to get the property of a JSON object. My attempt is as follows.

    JSONParser jsonParser = new JSONParser();
    try(FileReader reader = new FileReader("players.json")){                                     
       //Read JSON file                                  
       Object obj = jsonParser.parse(reader);                                                                
       JSONArray playersList = (JSONArray) obj; 
       //Below is the one which is having compilation issues                                                                 
       System.out.println(playersList.get(1).getString("name")); 

    } catch (FileNotFoundException e) {                                  
       // TODO Auto-generated catch block

           e.printStackTrace();
    } catch (IOException e) {                                    
       // TODO Auto-generated catch block

          e.printStackTrace();
     } catch (ParseException e) {                                    
       // TODO Auto-generated catch block                                    
          e.printStackTrace();
    }

There I am trying to get the name of the second object in the JSON array. But I couldn't find a way to call getString("name") as above. So I highly appreciate your help for this.

Json file is as follows.

      [
       {
         "_id": 1, 
         "name": "greg",
       },
       {
         "_id": 2,   
         "name": "freg gre",
       }
      ]

what is the compilation issue? (have you added the dependency? (on json-simple)) — xerx593
– xerx593, Commented Oct 18, 2019 at 19:29

Swayangjit · Accepted Answer · 2019-10-19 04:27:57Z

1

You can use like following

  JSONObject jsonObject = (JSONObject)playersList.get(1);
  String name = (String) jsonObject.get("name");

edited Oct 19, 2019 at 4:27

answered Oct 18, 2019 at 18:17

Swayangjit

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6 Comments

Zone Duo Over a year ago

There also compilation issue in getJSONObject method.

Swayangjit Over a year ago

which JSON library are you using?

Zone Duo Over a year ago

org.json.simple.*

Swayangjit Over a year ago

Updated the answer

Zone Duo Over a year ago

That answer was useful. But getString() method also having issues. String name = (String) jsonObject.get("name"); This worked

|

Ayushi Keshri · Accepted Answer · 2019-10-18 18:59:43Z

0

JSONParser jsonParser = new JSONParser();
    try(FileReader reader = new FileReader("players.json")){                                     

       Object obj = jsonParser.parse(reader);    
 JSONArray jsonArray = new JSONArray(obj);
    for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject json = jsonArray.getJSONObject(i);
        Iterator<String> keys = json.keys();

        while (keys.hasNext()) {
            String key = keys.next();
            System.out.println("Key :" + key + "  Value :" + json.get(key));
        }

    }

you just need to iterate through each object inside array and each object has keys and values fetch it within a loop.

answered Oct 18, 2019 at 18:59

Ayushi Keshri

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