...

public class MainActivity extends AppCompatActivity {

   ...

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

        ...
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_main, menu);

        //khusus proses search
        MenuItem item = menu.findItem(R.id.cari);
        SearchView searchView = (SearchView) item.getActionView();
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String s) { //ketika tekan enter
                Toast.makeText(getApplicationContext(), s, Toast.LENGTH_SHORT).show();
                return false;
            }

            @Override
            public boolean onQueryTextChange(String s) { //ketika text berubah
                return false;
            }
        });

        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.tambah:
                View view = findViewById(R.id.main_layout_id); //layout main activity harus constraint
                String message = "Snackbar action Tambah";
                int duration = Snackbar.LENGTH_SHORT; //alt + enter pada "Snackbar" untuk mendownload dependency
                Snackbar.make(view, message, duration).show();
                return true;
            case R.id.selip:
                Toast.makeText(getApplicationContext(), "action Selip", Toast.LENGTH_SHORT).show();
                return true;
            case R.id.auto_update:
                Toast.makeText(getApplicationContext(), "action Update", Toast.LENGTH_SHORT).show();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}