Android create a Json String

Question

I am trying to create a JSON String in the Android application.

    JSONArray jArrayFacebookData = new JSONArray();
    JSONObject jObjectType = new JSONObject();

    // put elements into the object as a key-value pair
    jObjectType.put("type", "facebook_login");

    jArrayFacebookData.put(jObjectType);

    // 2nd array for user information
    JSONObject jObjectData = new JSONObject();


    // Create Json Object using Facebook Data
    jObjectData.put("facebook_user_id", id);
    jObjectData.put("first_name", first_name);
    jObjectData.put("last_name", last_name);
    jObjectData.put("email", email);
    jObjectData.put("username", username);
    jObjectData.put("birthday", birthday);
    jObjectData.put("gender", gender);
    jObjectData.put("location", place);
    jObjectData.put("display_photo", display_photo_url);

    jArrayFacebookData.put(jObjectData);

Which creates a string like this

[
   {
      "type":"facebook_login"
   },
   {
      "birthday":"06\/22\/1986",
      "first_name":"Harsha",
      "username":"harshamv",
      "location":"Bangalore, India",
      "email":"[email protected]",
      "last_name":"Mv",
      "gender":"male",
      "facebook_user_id":"1423671254",
      "display_photo":"http:\/\/graph.facebook.com\/1423671254\/picture?type=large"
   }
]

I want to create a JSON string something like this

[
   "system":{
      "type":"facebook_login"
   },
   "data":{
      "birthday":"06\/22\/1986",
      "first_name":"Harsha",
      "username":"harshamv",
      "location":"Bangalore, India",
      "email":"[email protected]",
      "last_name":"Mv",
      "gender":"male",
      "facebook_user_id":"1423671254",
      "display_photo":"http:\/\/graph.facebook.com\/1423671254\/picture?type=large"
   }
]

Answer 1

JSONObject jArrayFacebookData = new JSONObject();
    JSONObject jObjectType = new JSONObject();

    // put elements into the object as a key-value pair
    jObjectType.put("type", "facebook_login");

    jArrayFacebookData.put("system", jObjectType);

    // 2nd array for user information
    JSONObject jObjectData = new JSONObject();


    // Create Json Object using Facebook Data
    jObjectData.put("facebook_user_id", id);
    jObjectData.put("first_name", first_name);
    jObjectData.put("last_name", last_name);
    jObjectData.put("email", email);
    jObjectData.put("username", username);
    jObjectData.put("birthday", birthday);
    jObjectData.put("gender", gender);
    jObjectData.put("location", place);
    jObjectData.put("display_photo", display_photo_url);

    jArrayFacebookData.put("data", jObjectData);

this will give you jsonObject, but not array, i don't see any point in using JSONArray. JSONObject is better in this case. you will see following output as String

{
   "system":{
      "type":"facebook_login"
   },
   "data":{
      "birthday":"06\/22\/1986",
      "first_name":"Harsha",
      "username":"harshamv",
      "location":"Bangalore, India",
      "email":"[email protected]",
      "last_name":"Mv",
      "gender":"male",
      "facebook_user_id":"1423671254",
      "display_photo":"http:\/\/graph.facebook.com\/1423671254\/picture?type=large"
   }
}

Answer 2

Create JSON objects for the jArrayFacebookData (not JSONArray as you have taken) and put jObjectType and jObjectData inside it.

Check this JSONObject put object method.

Update:

Your JSON is having error:

Valid JSON is:

{
    "system": {
        "type": "facebook_login"
    },
    "data": {
        "birthday": "06/22/1986",
        "first_name": "Harsha",
        "username": "harshamv",
        "location": "Bangalore, India",
        "email": "[email protected]",
        "last_name": "Mv",
        "gender": "male",
        "facebook_user_id": "1423671254",
        "display_photo": "http://graph.facebook.com/1423671254/picture?type=large"
    }
}

Final Solution:

     try
        {
    JSONObject jArrayFacebookData = new JSONObject();

        JSONObject jObjectType = new JSONObject();
        jObjectType.put("type", "facebook_login");

        JSONObject jObjectData = new JSONObject();
        jObjectData.put("facebook_user_id", "2323");
        jObjectData.put("first_name", "2323");
        jObjectData.put("last_name", "2323");
        //put other data here   

    jArrayFacebookData.put("system", jObjectType);
    jArrayFacebookData.put("data",jObjectData);

    System.out.println("==========> Final output => "+jArrayFacebookData.toString());

  }
  catch(Exception e)
  {

  }