如何在Android地图活动中显示特定的标记？

// 导入地图相关的库和依赖
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapActivity extends AppCompatActivity implements OnMapReadyCallback {

    private GoogleMap mMap;
    private MapView mMapView;

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

        // 在布局文件中添加地图视图
        mMapView = findViewById(R.id.mapView);
        mMapView.onCreate(savedInstanceState);
        mMapView.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // 设置地图的类型和缩放级别
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
        mMap.setMinZoomPreference(10);
        mMap.setMaxZoomPreference(18);

        // 创建标记对象
        LatLng markerPosition = new LatLng(37.7749, -122.4194);
        MarkerOptions markerOptions = new MarkerOptions()
                .position(markerPosition)
                .title("San Francisco")
                .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));

        // 在地图上添加标记
        mMap.addMarker(markerOptions);

        // 设置标记的点击事件
        mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
            @Override
            public boolean onMarkerClick(Marker marker) {
                // 处理标记的点击事件
                return true;
            }
        });

        // 设置地图的初始位置
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(markerPosition, 12));
    }

    @Override
    public void onResume() {
        super.onResume();
        mMapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mMapView.onDestroy();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mMapView.onLowMemory();
    }
}