Properly create new instance of JavaFX Chart - javafx

Question

I can't find a solution of the problem how to create new instance of chart. I tested the below code:
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.concurrent.ScheduledService;
import javafx.concurrent.Task;
import javafx.concurrent.WorkerStateEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.StackedBarChart;
import javafx.scene.chart.XYChart;
import javafx.stage.Stage;
import javafx.util.Duration;
public class MainApp extends Application
{
private StackedBarChart<String, Number> schart;
private CategoryAxis xAxis = new CategoryAxis();
private NumberAxis yAxis = new NumberAxis();
private StackedBarChart<String, Number> inits()
{
schart = new StackedBarChart<>(xAxis, yAxis);
schart.setAnimated(false);
schart.setTitle("Some_value");
return schart;
}
GenDatService data = new GenDatService();
#Override
public void start(Stage stage) throws Exception
{
StackedBarChart<String, Number> inits = inits();
data.setPeriod(new Duration(1000));
data.setOnSucceeded(new EventHandler<WorkerStateEvent>()
{
#Override
public void handle(final WorkerStateEvent workerStateEvent)
{
HashMap<String, Integer> value = data.getValue();
visuData(value);
}
});
data.setOnFailed(new EventHandler<WorkerStateEvent>()
{
#Override
public void handle(WorkerStateEvent t)
{
}
});
data.start();
Scene scene = new Scene(schart);
stage.setTitle("JavaFX and Maven");
stage.setScene(scene);
stage.show();
}
public void visuData(HashMap<String, Integer> map)
{
Set<String> keySet = map.keySet();
ObservableList<XYChart.Series<String, Number>> observableArrayList = FXCollections.observableArrayList();
ObservableList<String> observabtd = FXCollections.observableArrayList();
Iterator<String> iterator = keySet.iterator();
while (iterator.hasNext())
{
String column = iterator.next();
Integer value = map.get(column);
XYChart.Series<String, Number> series1 = new XYChart.Series<>();
XYChart.Data<String, Number> dataS1 = new XYChart.Data<>();
observabtd.add(column);
series1.setName(column);
dataS1.setXValue(column);
dataS1.setYValue(value);
series1.getData().add(dataS1);
observableArrayList.add(series1);
}
xAxis.setCategories(observabtd);
yAxis.setLabel("Some Value");
Scene scene = schart.getScene();
schart = new StackedBarChart<>(xAxis, yAxis);
scene.setRoot(schart);
schart.setAnimated(false);
schart.setData(observableArrayList);
}
public static void main(String[] args)
{
launch(args);
}
class GenDatService extends ScheduledService<HashMap<String, Integer>>
{
#Override
protected Task<HashMap<String, Integer>> createTask()
{
return new Task<HashMap<String, Integer>>()
{
#Override
protected HashMap<String, Integer> call() throws Exception
{
HashMap<String, Integer> usageData = new HashMap<>();
usageData.put("val_1", (int) (Math.random() * 100));
usageData.put("val_2", (int) (Math.random() * 100));
usageData.put("val_3", (int) (Math.random() * 100));
usageData.put("val_4", (int) (Math.random() * 100));
return usageData;
}
};
}
}
}
This code works fine, but the only problem is that I can't think of a way to properly set new instance of the StackedBarChart. This is the code whih I need to fix.
Scene scene = schart.getScene();
schart = new StackedBarChart<>(xAxis, yAxis);
scene.setRoot(schart);
Can you help me to fix this issue?