在地图上添加图层，计算机屏幕闪烁

Question

我通过在图层上添加一个点，然后在地图上添加一个图层，来向地图添加1点。我这样做了，添加屏幕图层的时间闪烁了，要求所有人避免闪烁

我使用Java 8 + Geotools

private void addClickPoint(MapMouseEvent ev){ 
        DirectPosition2D pos = ev.getMapPosition();
        double x = pos.x;
        double y = pos.y;

        SimpleFeatureTypeBuilder builder = new SimpleFeatureTypeBuilder();
        builder.setName("MyFeatureType");
        builder.setCRS(DefaultGeographicCRS.WGS84); // set crs
        builder.add("location", MultiPoint.class); // add geometry

        // build the type
        SimpleFeatureType TYPE = builder.buildFeatureType();
        // create features using the type defined
        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);

        // ===> Tạo ra 1 point khi click
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory(null);
        Coordinate coord = new Coordinate(x, y);
        Point point = geometryFactory.createPoint(coord);

        DefaultFeatureCollection featureCollection = new 
        DefaultFeatureCollection();
        featureBuilder.add(point);
        SimpleFeature feature = featureBuilder.buildFeature("FeaturePoint");
        featureCollection.add(feature); // Add feature 1, 2, 3, etc

        Style style = SLD.createPointStyle("circle", Color.BLUE, Color.BLUE, 0.3f, 15);
        Layer layer = new FeatureLayer(featureCollection, style);

        layer.setTitle("Click Point");
        map.layers().add(layer);
}

我希望屏幕不闪烁