Как использовать спиннер из фрагментов и извлечь его из моего 4-го фрагмента и моей следующей кнопки в разделе «Бронирование»?

Question

Итак, я собираюсь установить спиннер в моем 1-м фрагменте, и мне нужны данные onItemSelected из 1-го фрагмента, а позже я хочу показать им данные в 4-м фрагменте, но моя следующая и предыдущая кнопка находится на операции бронирования. Поэтому я пытаюсь ошибиться в своей активности бронирования. Но я получаю, что logcat говорит, что мой Bundle пуст. Может кто-то мне помочь, пожалуйста!! Я не знаю, как решить это.

Вот моя ошибка logcat

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.VehicleServiceBooking/com.example.VehicleServiceBooking.BookingActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
        at android.app.ActivityThread.access$800(ActivityThread.java:151)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5254)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
        at com.example.VehicleServiceBooking.BookingActivity.onCreate(BookingActivity.java:192)

Это мой 1 фрагмент

@Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);
        View itemView = inflater.inflate(R.layout.fragment_booking_step_one,container,false);
        unbinder = ButterKnife.bind(this,itemView);

        car_model = (Spinner)itemView.findViewById(R.id.car_millage_spinner);
        service_types = (Spinner)itemView.findViewById(R.id.service_type_spinner);
        car_millage = (Spinner)itemView.findViewById(R.id.car_model_spinner);

        //get spinner values
        getSpinners();

        initView();
        loadAllSalon();

        return itemView;
    }

    private void getSpinners() {
        ArrayAdapter carmodel = ArrayAdapter.createFromResource(getContext(),
                R.array.car_models, android.R.layout.simple_spinner_dropdown_item);
        car_model.setAdapter(carmodel);

        car_model.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {

                String selectedItemText = car_model.getSelectedItem().toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });

        ArrayAdapter serviceTypes = ArrayAdapter.createFromResource(getContext(),
                R.array.service_types, android.R.layout.simple_spinner_dropdown_item);
        service_types.setAdapter(serviceTypes);

        service_types.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {

                String selectedItemText = service_types.getSelectedItem().toString();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
        ArrayAdapter mileageCar = ArrayAdapter.createFromResource(getContext(),
                R.array.car_millages, android.R.layout.simple_spinner_dropdown_item);
        car_millage.setAdapter(mileageCar);

        car_millage.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {

                String selectedItemText = car_millage.getSelectedItem().toString();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
    }

Здесь моя кнопка BookingActivity. java следующая кнопка и предыдущая, и где я объявляю пакет, чтобы получить значение в счетчике в 1stFragment

@OnClick(R.id.btn_next_step)
    void nextClick(){
        if (Common.step < 3 || Common.step == 0)
        {
            Common.step++;
            if (Common.step == 1)
            {
                if (Common.currentSalon != null)
                    loadBarberBySalon(Common.currentSalon.getSalonId());
                    String ServiceType = String.valueOf(service_types.getSelectedItem().toString());
                    String carMillage = String.valueOf(car_millage.getSelectedItem().toString());
                    String carModel = String.valueOf(car_model.getSelectedItem().toString());

                    if (ServiceType.equals("Choose Service") | carMillage.equals("Choose Car Millage") || carModel.equals("Choose Car Model"))
                        return;
                    else
                    {
                        Intent gotoBookingStep4 = new Intent(this, BookingStep4Fragment.class);
                        Bundle extras = new Bundle();
                        extras.putString("CarMillageData", carMillage);
                        extras.putString("CarModelData", carModel);
                        extras.putString("Service_Type",ServiceType);
                        extras.putString("newServiceTypeFromIntent", ServiceTypeFromIntent);
                        extras.putString("CarMillageFromCarActivity", CarMillageDataFromIntent);
                        extras.putString("CarModelFromCarActivity", CarModelDataFromIntent);
                        gotoBookingStep4.putExtras(extras);
                        startActivityForResult(gotoBookingStep4,0);
                    }
            }
            else if (Common.step == 2)
            {
                if (Common.currentBarber != null)
                    loadTimeSlotOfBarber(Common.currentBarber.getBarberId());
            }
            else if (Common.step == 3)
            {
                if (Common.currentTimeSlot != -1)
                    confirmBooking();
            }
            viewPager.setCurrentItem(Common.step);
        }
    }

Это моя onCreate на странице BookingActivity

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_booking);
        ButterKnife.bind(BookingActivity.this);

        Bundle extras = getIntent().getExtras();
        ServiceTypeFromIntent = extras.getString("Service_Type");
        CarMillageDataFromIntent = extras.getString("CarMillageData");
        CarModelDataFromIntent = extras.getString("CarModelData");
        car_model = (Spinner)findViewById(R.id.car_millage_spinner);
        service_types = (Spinner)findViewById(R.id.service_type_spinner);
        car_millage = (Spinner)findViewById(R.id.car_model_spinner);

        dialog = new SpotsDialog.Builder().setContext(this).setCancelable(false).build();

        localBroadcastManager = LocalBroadcastManager.getInstance(this);
        localBroadcastManager.registerReceiver(buttonNextReceiver,new IntentFilter(Common.KEY_ENABLE_BUTTON_NEXT));

        setupStepView();
        setColorButton();

        viewPager.setAdapter(new MyViewPagerAdapter(getSupportFragmentManager()));
        viewPager.setOffscreenPageLimit(4);
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int i, float v, int i1) {

            }

            @Override
            public void onPageSelected(int i) {
                stepView.go(i,true);
                if (i == 0)
                    btn_previous_step.setEnabled(false);
                else
                    btn_previous_step.setEnabled(true);

                btn_next_step.setEnabled(false);
                setColorButton();
            }

            @Override
            public void onPageScrollStateChanged(int i) {

            }
        });
    }

Это мой 4-й фрагмент, где я хочу, чтобы пользователь данных выбирал во фрагменте счетчика1

@Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ifcmApi = RetrofitClient.getInstance().create(IFCMApi.class);

        Bundle extras2 = getActivity().getIntent().getExtras();
        CarMillageDataFromIntent = extras2.getString("CarMillageFromCarActivity");
        CarModelDataFromIntent = extras2.getString("CarModelFromCarActivity");
        ServiceTypeFromIntent = extras2.getString("ServiceTypeFromService");

        //init object
        AssignMyValues();


        simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy");
        localBroadcastManager = LocalBroadcastManager.getInstance(getContext());
        localBroadcastManager.registerReceiver(confirmBookingReceiver,new IntentFilter(Common.KEY_CONFIRM_BOOKING));

        dialog = new SpotsDialog.Builder().setContext(getContext()).setCancelable(false)
                .build();
    }

    private void AssignMyValues() {
        textViewType.setText("" + ServiceTypeFromIntent + "");

        textViewCarMillage.setText("" + CarMillageDataFromIntent + "");

        textViewModel.setText("" + CarModelDataFromIntent + "");

        //extractx int from String
        CarMillageDataFromIntent = CarMillageDataFromIntent.replaceAll("\\D+", "");

        //covert car millage to integer
        millage_value = Integer.parseInt(CarMillageDataFromIntent);

        //setting user price
        if (millage_value == 1000 || millage_value < 15000) {
            millage_price_result = 100;

            //converting int to String
            millage_price_value = String.valueOf(millage_price_result);

            //set price in String format
            textViewPrice.setText(" RM " + millage_price_value + "");
        } else if (millage_value == 15000 || millage_value < 30000) {
            millage_price_result = 200;

            //converting int to String
            millage_price_value = String.valueOf(millage_price_result);

            //set price in String format

            textViewPrice.setText(" RM " + millage_price_value + "");
        } else if (millage_value == 30000 || millage_value < 50000) {

            millage_price_result = 300;

            //converting int to String
            millage_price_value = String.valueOf(millage_price_result);

            //set price in String format

            textViewPrice.setText(" RM " + millage_price_value + "");
        } else if (millage_value == 50000 || millage_value < 80000) {
            millage_price_result = 400;

            //converting int to String
            millage_price_value = String.valueOf(millage_price_result);

            //set price in String format

            textViewPrice.setText(" RM " + millage_price_value + "");
        }



    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        compositeDisposable.clear();
        localBroadcastManager.unregisterReceiver(confirmBookingReceiver);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);
        View itemView =  inflater.inflate(R.layout.fragment_booking_step_four,container,false);
        unbinder = ButterKnife.bind(this,itemView);

        textViewCarMillage = (TextView)itemView.findViewById(R.id.service_millage_text);
        textViewType = (TextView) itemView.findViewById(R.id.service_types_text);
        textViewModel = (TextView) itemView.findViewById(R.id.service_model_text);
        textViewPrice = (TextView)itemView.findViewById(R.id.service_estimatedprice_text);

        return itemView;
    }