Spinner и Фрагменты

public class MainActivity extends AppCompatActivity {
 
    Spinner spinner1, spinner2;
    FragmentOne fragmentOne;
    FragmentTwo fragmentTwo;
 
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        fragmentOne = new FragmentOne();
 
        spinner1 = findViewById(R.id.spinner1);
        String selected = spinner1.getSelectedItem().toString();
        Toast.makeText(getApplicationContext(), selected, Toast.LENGTH_SHORT).show();
 
        ArrayAdapter<String> adapter = new ArrayAdapter<>(
                this, R.layout.custom_spinner, getResources().getStringArray(R.array.List)
 
        );
        adapter.setDropDownViewResource(R.layout.customs_spinner_dropdown);
        spinner1.setAdapter(adapter);
 
        // заголовок
 
        spinner2 = findViewById(R.id.spinner2);
        String selected1 = spinner2.getSelectedItem().toString();
        Toast.makeText(getApplicationContext(), selected1, Toast.LENGTH_SHORT).show();
 
        ArrayAdapter<String> adapter1 = new ArrayAdapter<>(
                this, R.layout.custom_spinner, getResources().getStringArray(R.array.ListTwo)
        );
        adapter1.setDropDownViewResource(R.layout.customs_spinner_dropdown);
        spinner2.setAdapter(adapter1);
        ArrayAdapter<String> adapter2 = new ArrayAdapter<>(
                this, R.layout.custom_spinner, getResources().getStringArray(R.array.fragments)
        );
        adapter2.setDropDownViewResource(R.layout.customs_spinner_dropdown);
        spinner1.setAdapter(adapter2);
 
        spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(getBaseContext(), "Position = " + i, Toast.LENGTH_SHORT).show();
                switch (i) {
                    case 0:
 
                        break;
                    case 1:
 
                        break;
 
 
                }
            }
 
            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {
 
            }
        });
    }
 
    public void setFragment(Fragment fragment) {
 
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.spinner1, fragment);
        fragmentTransaction.commit();
    }