BottomNavigationView – How to avoid recreation of Fragments and reuse them

I had similar issue, but this code solved my problem.

public class MainActivity extends AppCompatActivity {

    boolean doubleBackToExitPressedOnce = false;
    final Fragment fragment1 = new HomeFragment();
    final Fragment fragment2 = new DashboardFragment();
    final Fragment fragment3 = new NotificationsFragment();
    final FragmentManager fm = getSupportFragmentManager();
    Fragment active = fragment1;
    BottomNavigationView navigation;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        navigation = (BottomNavigationView) findViewById(R.id.navigation);
        navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
        setFragment(fragment1, "1", 0);
    }


    private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
            = new BottomNavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.navigation_home:
                    setFragment(fragment1, "1", 0);
                    return true;
                case R.id.navigation_dashboard:
                    setFragment(fragment2, "2", 1);
                    return true;
                case R.id.navigation_notifications:
                    setFragment(fragment3, "3", 2);
                    return true;
            }
            return false;
        }
    };

    public void setFragment(Fragment fragment, String tag, int position) {
        if (fragment.isAdded()) {
            fm.beginTransaction().hide(active).show(fragment).commit();
        } else {
            fm.beginTransaction().add(R.id.main_container, fragment, tag).commit();
        }
        navigation.getMenu().getItem(position).setChecked(true);
        active = fragment;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        if (id == R.id.action_settings) {
            startActivity(new Intent(MainActivity.this, SettingsActivity.class));
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onBackPressed() {
        if (active == fragment1) {
            if (doubleBackToExitPressedOnce) {
                super.onBackPressed();
                return;
            }
            this.doubleBackToExitPressedOnce = true;
            Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
        } else {
            setFragment(fragment1, "1", 0);
        }
    }
}