public void addToQueue(Request request) {
   if (request != null) {
     request.setTag(this);
     if (fRequestQueue == null) fRequestQueue = volley.getRequestQueue();
     request.setRetryPolicy(
         new DefaultRetryPolicy(60000, 3, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
     onPreStartConnection();
     fRequestQueue.add(request);
   }
 }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    volley = VolleyS.getInstance(this);
    fRequestQueue = volley.getRequestQueue();
    setContentView(R.layout.activity_main);
    current = Backendless.UserService.CurrentUser();
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
    String appVersion = "v1";
    Backendless.initApp(
        this,
        "F89F55EE-64AD-32BF-FFE1-96C258DA8800",
        "C7F9D9B6-6A7E-6FCF-FF7E-B1D7272E9900",
        appVersion);
    SharedPreferences sharedPreferences = getSharedPreferences("myData", Context.MODE_PRIVATE);
    String name = sharedPreferences.getString("name", "");

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle =
        new ActionBarDrawerToggle(
            this,
            drawer,
            toolbar,
            R.string.navigation_drawer_open,
            R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();
    String urlpost = "http://10.10.3.21:3000/topcandidatos";
    JsonArrayRequest req =
        new JsonArrayRequest(
            urlpost,
            new Response.Listener<JSONArray>() {
              @Override
              public void onResponse(JSONArray response) {
                for (int i = 0; i < response.length(); i++) {
                  Candidato candidato = new Candidato();
                  try {
                    JSONObject jsonObject = response.getJSONObject(i);
                    candidato.setApellidos(jsonObject.getString("can_Apellido"));
                    candidato.setNombres(jsonObject.getString("can_Nombre"));
                    candidato.setId(jsonObject.getInt("can_Codigo"));
                    candidato.setFoto(jsonObject.getString("can_Foto"));
                    candidato.setPopularidad(jsonObject.getDouble("percent"));
                    candidato.setVotos(jsonObject.getInt("Respuestas"));
                    candidatos.add(candidato);
                  } catch (JSONException e) {
                    e.printStackTrace();
                  }
                }
                candidatoAdapter =
                    new CandidatoAdapter(
                        MainActivity.this, R.layout.top_item_candidato, candidatos);
                ListView tablesListView = (ListView) findViewById(R.id.mainList);
                candidatoAdapter.notifyDataSetChanged();
                tablesListView.setAdapter(candidatoAdapter);
                /*try {
                    VolleyLog.v("Response:%n %s", response.toString(4));
                } catch (JSONException e) {
                    e.printStackTrace();
                }*/
              }
            },
            new Response.ErrorListener() {
              @Override
              public void onErrorResponse(VolleyError error) {
                VolleyLog.e("Error: ", error.getMessage());
              }
            });
    addToQueue(req);
    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
    View header = navigationView.getHeaderView(0);
    ImageView imageView = (ImageView) header.findViewById(R.id.imageView);
    TextView title = (TextView) header.findViewById(R.id.titleHeader);
    TextView email = (TextView) header.findViewById(R.id.email);
    Picasso.with(this)
        .load(
            "https://graph.facebook.com/"
                + current.getProperty("email").toString()
                + "/picture?type=large")
        .resize(110, 110)
        .centerCrop()
        .into(imageView);
    title.setText(current.getProperty("name").toString());
    email.setText(current.getProperty("fb_email").toString());
  }