Data driven styling

public class SampleDataDrivenStylingActivity extends AppCompatActivity implements Style.OnStyleLoaded  {

    private MapView mapView;
    private TrimbleMapsMap map;
    private final String SOURCE_ID = "tristatepoints";
    private final String LAYER_ID = "tristatepoints";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);// Authorize the api key for the session.
        // .apiKey() requires your Trimble Maps API key
        TrimbleMapsAccount trimbleMapsAccount = TrimbleMapsAccount.builder()
                .apiKey("Your-API-key-here")
                .addLicensedFeature(LicensedFeature.MAPS_SDK)
                .build();

        // Initialize the session
        TrimbleMapsAccountManager.initialize(trimbleMapsAccount);
        TrimbleMapsAccountManager.awaitInitialization();

        // Get an instance of the map, done before the layout is set.
        TrimbleMaps.getInstance(this);
        setContentView(R.layout.activity_sample_data_driven_styling);

        // Set up the MapView from the layout
        mapView = (MapView) findViewById(R.id.mapView);

        // the onMapReadyCallback is fired when the map is ready to be worked with
        mapView.getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(@NonNull TrimbleMapsMap trimbleMapsMap) {
                // The TrimbleMapsMap object is created, now a style can be applied to render a map.
                map = trimbleMapsMap;
                CameraPosition position = new CameraPosition.Builder()
                        .target(new LatLng(41.36290180612575, -74.6946761628674))
                        .zoom(13)
                        .build();
                map.setCameraPosition(position);

                // This class implements the onStyleLoaded method, that will be called when
                // the style has been loaded.
                map.setStyle(Style.MOBILE_NIGHT, SampleDataDrivenStylingActivity.this);
            }
        });
    }

    @Override
    public void onStyleLoaded(Style style) {
        // In this example a .json file from the assets folder is being used as the source
        // This sample can be found here: @TODO ADD LINK
        // Geojson can either be passed in as a string or the result of a URI call.

        try {
            // Create a source and add it to the style. Important to note, sources are linked to styles.
            // If you change the style you may need to re-add your source and layers
            style.addSource(new GeoJsonSource(SOURCE_ID, new URI("asset://tristate.json")));
            // See sample JSON file (tristate.json) below

            // Create a CircleLayer to display our source information.
            CircleLayer circleLayer = new CircleLayer(LAYER_ID, SOURCE_ID);
            circleLayer.setProperties(
                    // Changing the circle radius and stroke width based on the zoom level
                    PropertyFactory.circleRadius(interpolate(linear(),
                            zoom(),
                            stop(12f, 2f),
                            stop(22f, 10f)
                    )),

                    PropertyFactory.circleStrokeWidth(interpolate(linear(),
                            zoom(),
                            stop(12f, 1f),
                            stop(22f, 12f)
                    )),

                    // Change the color of the circle stroke based on the "state" property in the
                    // json source data. The first color used is the default color if no 'match' is
                    // found
                    PropertyFactory.circleStrokeColor(
                            Expression.match(Expression.get("state"), Expression.color(Color.BLACK),
								Expression.stop("PA", Expression.color(Color.GREEN)),
								Expression.stop("NY", Expression.color(Color.BLUE)),
								Expression.stop("NJ", Expression.color(Color.RED))
								)
                    ),
                    PropertyFactory.circleColor(Color.WHITE)
            );

            // add the layer
            style.addLayer(circleLayer);

        } catch (URISyntaxException e) {
            e.printStackTrace();
        }

    }
	
    /**
     * Activity Overrides
     */
    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mapView.onLowMemory();
    }
    @Override
    public void onStart() {
        super.onStart();
        mapView.onStart();
    }
    @Override
    public void onResume() {
        super.onResume();
        mapView.onResume();
    }
    @Override
    public void onStop() {
        super.onStop();
        mapView.onStop();
    }
    @Override
    public void onPause() {
        super.onPause();
        mapView.onPause();
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        mapView.onDestroy();
    }
}