标记无法在具有数据库Firebase的地图中显示

Question

iam无法使用数据库Firebase在地图上显示标记，但是成功获取了，请帮助

我试图在maps.java中更改代码，但标记仍然无法显示

我的数据库

Maps.java

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,LocationListener,GoogleMap.OnMarkerClickListener {
private GoogleMap mMap;
private ChildEventListener mChildEventListener;
private DatabaseReference mUploads;
Marker marker;
@Override
protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);


    SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
    ChildEventListener mChildEventListener;
    mUploads = FirebaseDatabase.getInstance().getReference("uploads");
    mUploads.push().setValue(marker);
}
@Override
public void onMapReady(GoogleMap googleMap){
    mMap = googleMap;
    googleMap.setOnMarkerClickListener(this);
    googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
    mUploads.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot s : dataSnapshot.getChildren()){
                Upload upload = s.getValue(Upload.class);
                LatLng location = new LatLng(upload.getLatitude(),upload.getLongitude());
                Marker myMarker = mMap.addMarker(new MarkerOptions().position(location).title(upload.getName()));
                myMarker.setIcon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_YELLOW));


            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}

@Override
public void onLocationChanged(Location location) {

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}

@Override
public boolean onMarkerClick(Marker marker) {
    return false;
}

}

我尝试更改地图中的代码[！[在此处输入图片描述] [2]] [2] .java，但bu仍然无法在地图中显示