Gmap Draggable Markers

@Named
@ViewScoped
public class DraggableMarkersView implements Serializable {

    private MapModel draggableModel;

    private Marker marker;

    @PostConstruct
    public void init() {
        draggableModel = new DefaultMapModel();

        //Shared coordinates
        LatLng coord1 = new LatLng(36.879466, 30.667648);
        LatLng coord2 = new LatLng(36.883707, 30.689216);
        LatLng coord3 = new LatLng(36.879703, 30.706707);
        LatLng coord4 = new LatLng(36.885233, 30.702323);

        //Draggable
        draggableModel.addOverlay(new Marker(coord1, "Konyaalti"));
        draggableModel.addOverlay(new Marker(coord2, "Ataturk Parki"));
        draggableModel.addOverlay(new Marker(coord3, "Karaalioglu Parki"));
        draggableModel.addOverlay(new Marker(coord4, "Kaleici"));

        for (Marker premarker : draggableModel.getMarkers()) {
            premarker.setDraggable(true);
        }
    }

    public MapModel getDraggableModel() {
        return draggableModel;
    }

    public void onMarkerDrag(MarkerDragEvent event) {
        marker = event.getMarker();

        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_INFO,
                        "Marker Dragged",
                        "Lat:" + marker.getLatlng().getLat() + ", Lng:" + marker.getLatlng().getLng()));
    }
}