private void addProductToCart(String productId) {

    CartentiaApplication.MY_CART_PRODUCTS.add(productId);
    AddCartRequest addCartRequest = new AddCartRequest();
    addCartRequest.setUserID(PreferenceManager.getUserID());
    addCartRequest.setProductID(productId);
    addCartRequest.setGroupID(PreferenceManager.getGroupID());
    addCartRequest.setID(1);
    String jsnRequest = new Gson().toJson(addCartRequest);
    Request request =
        new JsonPostRequestHandler(
            Request.Method.POST,
            Constants.Url.ADD_CART,
            jsnRequest,
            AddMyCartResponse.class,
            new Response.Listener<AddMyCartResponse>() {
              @Override
              public void onResponse(AddMyCartResponse response) {}
            },
            new Response.ErrorListener() {
              @Override
              public void onErrorResponse(VolleyError error) {}
            });
    VolleyManager.getInstance().addRequestToQueue(request, "AddCart");
  }
 @Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   if (!TextUtils.isEmpty(PreferenceManager.getUserID())) {
     navigateToDashBoardActivity();
     return;
   }
   setContentView(R.layout.activity_login);
   initPresenter();
   initView();
 }
  private void initNavDrawer() {
    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawerToggle =
        new ActionBarDrawerToggle(
            this, drawerLayout, toolbar, R.string.app_name, R.string.app_name) {
          @Override
          public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
          }

          @Override
          public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
          }

          @Override
          public boolean onOptionsItemSelected(MenuItem item) {
            if (item != null && item.getItemId() == android.R.id.home) {
              if (drawerLayout.isDrawerOpen(Gravity.LEFT)) {
                drawerLayout.closeDrawer(Gravity.LEFT);
              } else drawerLayout.openDrawer(Gravity.LEFT);
            }
            return false;
          }
        };
    drawerLayout.setDrawerListener(drawerToggle);
    navigationView = (NavigationView) findViewById(R.id.navigation);
    navigationView
        .getMenu()
        .findItem(R.id.my_cart)
        .setTitle("" + PreferenceManager.getName() + "'s Cart");
    navigationView.setNavigationItemSelectedListener(
        new NavigationView.OnNavigationItemSelectedListener() {
          @Override
          public boolean onNavigationItemSelected(MenuItem menuItem) {
            drawerLayout.closeDrawers();
            menuItem.setChecked(true);
            switch (menuItem.getItemId()) {
              case R.id.my_cart:
                loadMyCartFragment();
                break;
              case R.id.order_history:
                break;
              case R.id.about_us:
                break;
              case R.id.logout:
                logout();
                break;
            }
            return true;
          }
        });
    drawerToggle.syncState();
  }
 private void logout() {
   PreferenceManager.setUserID(null);
   Intent loginIntent = new Intent(this, LoginActivity.class);
   startActivity(loginIntent);
   finishAffinity();
 }