Convert string to json object gives an error

Question

I have to send the json array to web server. I have created json array from array list. I have a helper class which sends json object to server.

So I want to convert the json array to json object.

I tried to do this:

Async Task:

public class SendMultipleInvitesAsyncTask extends AsyncTask<String, Void, JSONObject> {

    private Context context;
    JSONArray array = new JSONArray();

    public SendMultipleInvitesAsyncTask(Context context)
    {

        this.context = context;

    }

        @Override
        protected JSONObject doInBackground(String... params) {
            try {
                String api = context.getResources().getString(R.string.server_url) + "contactsapi/sendMultipleInvite.php";

                JSONObject obj = new JSONObject(params[0]);

                ServerRequest request = new ServerRequest(api,obj);
                return request.sendRequest();

            } catch(JSONException je) {
                return Excpetion2JSON.getJSON(je);
            }
        }

Activity :

public class SendMultipleInvites extends AppCompatActivity {

private ArrayList<Invitation> invitationArrayList;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_send_multiple_invites);

  invitationArrayList = new ArrayList<>();

    Invitation invitation = new Invitation("3","17/02/2016","55165122","1","user10");

    invitationArrayList.add(invitation);

    invitation = new Invitation("3","17/02/2016","282751221","1","user10");

    invitationArrayList.add(invitation);

   // JSONArray jsArray = new JSONArray(invitationArrayList);


    Gson gson=new Gson();
    String toServer=gson.toJson(invitationArrayList);



    new SendMultipleInvitesAsyncTask(SendMultipleInvites.this).execute(toServer);

But this gives me an error that json object can not be converted to json array.

I want to send input of json array like this:

{
"invitations": [
    {

   "sender_id" : 3,
    "date" : "12/08/2016",
    "invitee_no" : "196756456",
    "status" : "1",
    "user_name" : "user10"

    },
    {

   "sender_id" : 3,
    "date" : "12/08/2016",
    "invitee_no" : "13633469",
    "status" : "1",
    "user_name" : "user9"

    }
  ]

}

How can I do this? How to pass it through an async task. Or what is going wrong here? Please help Thank you..

Answer 1

invitationArrayList is your ArrayList so jo get a JSON array. If you want to wrap this array in a JSON object you have to this in java as well.

For example:

String toServer = gson.toJson(
    Collections.singletonMap("invitations", invitationArrayList)
);

(assumed that gson.toJson works as expected. I'm no gson expert because I'm mostly use jackson ...)

JavaDoc for Collections.singletonMap : https://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#singletonMap(K,%20V)