Take the value of Try and fix to Return

Question

I would like to redeem the result value that is inside Try, the code is correct directly in Activity, but when I put in asyncTask I cannot set it in the Return result;.

Follows the code AsyncTask:

import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

@SuppressWarnings("ALL")
public class MecanismoString extends AsyncTask <String, String, String> {

    RequestQueue requestQueue;
    StringRequest stringRequest;
    private Interfacestring execinterface;
    private Context context;

    String tipo, url, usuario, senha, result;

    Toast toast;

    public MecanismoString (Context context, Interfacestring execinterface){
        this.context = context;
        this.execinterface = execinterface;
    }




    @Override
    public String doInBackground(String... params) {

        Log.i("Script", "1 ->" + params[0]);
        Log.i("Script", "2 ->" + params[1]);
        Log.i("Script", "3 ->" + params[2]);
        Log.i("Script", "4 ->" + params[3]);

        tipo = params[0];
        url = params[1];
        usuario = params[2];
        senha = params[3];

        requestQueue = Volley.newRequestQueue(context);

        stringRequest = new StringRequest(Request.Method.POST,
                url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {

                        try {

                            JSONObject jsonObject = new JSONObject(response);


                            int perfil = jsonObject.getInt("perfil");

                           result = String.valueOf(perfil);



                        } catch (Exception e) {



                        }



                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                    }
                }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<>();
                params.put("login", usuario);
                params.put("senha", senha);
                return params;
            }
        };
        requestQueue.add(stringRequest);


        return result;
    }

    private void chamarJSON() {

        requestQueue = Volley.newRequestQueue(context);

        stringRequest = new StringRequest(Request.Method.POST,
                url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {

                        try {

                            JSONObject jsonObject = new JSONObject(response);


                            int perfil = jsonObject.getInt("perfil");

                            String result = String.valueOf(perfil);


                        } catch (Exception e) {
                            Log.v("LogLogin", e.getMessage());

                        }

                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Log.e("LogLogin", error.getMessage());
                    }
                }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<>();
                params.put("login", usuario);
                params.put("senha", senha);
                return params;
            }
        };
        requestQueue.add(stringRequest);
    }


    @Override
    protected void onPostExecute(String result) {



        execinterface.carregarString(result);

    }

}